Login- Download PDF Manual
-
Volume Up
Volume Down
Mode Advance
Seek Up
Seek Down
Resistance
1.210 Kilohms
± 1%
3.010 Kilohms
± 1%
0.0511 Kilohms
± 1%
0.261 Kilohms
± 1%
0.681 Kilohms
± 1%
Pre-Set Station
0.162 Kilohms
Advance
± 1%
(3) Reconnect the battery negative cable. Turn the ignition switch to the On position. Check for 5 volts at the radio control mux circuit cavities of the steer- ing wheel wire harness connectors for both remote radio switches. If OK, go to Step 4. If not OK, repair the open or shorted radio control mux circuit to the Integrated Power Module (IPM) as required.
(4) Disconnect and isolate the battery negative cable. Disconnect the 22-way instrument panel wire harness connector from the IPM. Check for continu- ity between the remote radio switch ground circuit cavities of the steering wheel wire harness connec- tors for both remote radio switches and a good ground. There should be no continuity. If OK, go to Step 5. If not OK, repair the shorted remote radio switch ground circuit to the IPM as required.
connectors
(5) Check for continuity between the remote radio switch ground circuit cavities of the steering wheel wire harness for both remote radio switches and the 22-way instrument panel wire har- ness connector for the IPM. There should be continu- ity. If OK, refer to the proper Diagnostic Procedures manual to test the IPM and the PCI data bus. If not OK, repair the open remote radio switch ground cir- cuit as required.
AUDIO
8A - 12
REMOTE SWITCHES (Continued) REMOVALWARNING: DISABLE THE AIRBAG SYSTEM BEFORE ATTEMPTING ANY STEERING WHEEL, STEERING COLUMN, SEAT BELT TENSIONER, SIDE AIRBAG, OR INSTRUMENT PANEL COMPONENT DIAGNOSIS OR SERVICE. DISCONNECT AND ISO- LATE THE BATTERY NEGATIVE (GROUND) CABLE, THEN WAIT TWO MINUTES FOR THE AIRBAG SYS- TEM CAPACITOR TO DISCHARGE BEFORE PER- FORMING FURTHER DIAGNOSIS OR SERVICE. THIS IS THE ONLY SURE WAY TO DISABLE THE AIRBAG SYSTEM. FAILURE TO TAKE THE PROPER PRE- CAUTIONS COULD RESULT IN ACCIDENTAL AIR- BAG DEPLOYMENT AND POSSIBLE PERSONAL INJURY.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the driver airbag from the vehicle (Refer to 8 - ELECTRICAL/RESTRAINTS/DRIVER AIRBAG - REMOVAL).
(3) Remove the speed control switches (Refer to 8 -
CONTROL/SWITCH
ELECTRICAL/SPEED REMOVAL).
(4) Unplug the wire harness connector from the
remote radio switch(es).
Fig.15REMOTESWITCHES
1 - REMOTE SWITCH 2 - SPEED CONTROL SWITCH 3 - BOLT
(5) Depress the tabs on each side of each switch and push the switch through the rear steering wheel cover (Fig. 15).
INSTALLATION
WARNING: DISABLE THE AIRBAG SYSTEM BEFORE ATTEMPTING ANY STEERING WHEEL, STEERING COLUMN, SEAT BELT TENSIONER, SIDE
DR
AIRBAG, OR INSTRUMENT PANEL COMPONENT DIAGNOSIS OR SERVICE. DISCONNECT AND ISO- LATE THE BATTERY NEGATIVE (GROUND) CABLE, THEN WAIT TWO MINUTES FOR THE AIRBAG SYS- TEM CAPACITOR TO DISCHARGE BEFORE PER- FORMING FURTHER DIAGNOSIS OR SERVICE. THIS IS THE ONLY SURE WAY TO DISABLE THE AIRBAG SYSTEM. FAILURE TO TAKE THE PROPER PRE- CAUTIONS COULD RESULT IN ACCIDENTAL AIR- BAG DEPLOYMENT AND POSSIBLE PERSONAL INJURY.
(1) Install remote radio switch to the steering
wheel.
switch.
(2) Connect the wire harness to the remote radio
(3) Install the speed control switches (Refer to 8 -
CONTROL/SWITCH
ELECTRICAL/SPEED INSTALLATION).
(4) Install the driver airbag (5) Connect the battery negative cable.
SPEAKER DESCRIPTION
STANDARD
The standard equipment speaker system includes speakers in four locations. One 15.2 X 22.8 centime- ter (6 X 9 inch) full-range speaker is located in each front door. There is also one full-range 13.3 centime- ter (5.25 inch) diameter full-range speaker located in each rear door.
PREMIUM
The optional premium speaker system features eleven Premium model speakers in seven locations. Each of the standard speakers is replaced with Pre- mium model speakers. One 8.8 centimeter (3.50 inch) diameter speaker is located on each end of the instrument panel top pad. One 6.3 centimeter (2.50
inch) diameter speaker is located in the center of the instrument panel top pad. One 15.2 X 22.8 centime- ter (6 X 9 inch) Premium speaker is located in each front door. There is also one coaxial 13.3 centimeter (5.25 inch) diameter Premium full-range speaker located in each rear door. The premium speaker sys- tem also includes a power amplifier mounted behind the glove box. The total available power of the pre- mium speaker system is 240 watts.OPERATION
Two wires connected to each speaker, one feed cir- cuit (+) and one return circuit (–), allow the audio output signal electrical current to flow through the voice coil. For complete circuit diagrams, refer to the
DR SPEAKER (Continued)
appropriate wiring information. The wiring informa- tion includes wiring diagrams, proper wire and con- nector repair procedures, details of wire harness routing and retention, connector pin-out information and location views for the various wire harness con- nectors, splices and grounds.
DIAGNOSIS AND TESTING - SPEAKER
Any diagnosis of the Audio system should begin with the use of the DRB IIIt diagnostic tool. For information on the use of the DRB IIIt, refer to the appropriate Diagnostic Service Manual.
Refer to the appropriate wiring information. The wiring information includes wiring diagrams, proper wire and connector repair procedures, details of wire harness routing and retention, connector pin-out information and location views for the various wire harness connectors, splices and grounds.
WARNING: DISABLE THE AIRBAG SYSTEM BEFORE ATTEMPTING ANY STEERING WHEEL, STEERING COLUMN, SEAT BELT TENSIONER, SIDE AIRBAG, OR INSTRUMENT PANEL COMPONENT DIAGNOSIS OR SERVICE. DISCONNECT AND ISO- LATE THE BATTERY NEGATIVE (GROUND) CABLE, THEN WAIT TWO MINUTES FOR THE AIRBAG SYS- TEM CAPACITOR TO DISCHARGE BEFORE PER- FORMING FURTHER DIAGNOSIS OR SERVICE. THIS IS THE ONLY SURE WAY TO DISABLE THE AIRBAG SYSTEM. FAILURE TO TAKE THE PROPER PRE- CAUTIONS COULD RESULT IN ACCIDENTAL AIR- BAG DEPLOYMENT AND POSSIBLE PERSONAL INJURY.
CAUTION: The speaker output of the radio is a “floating ground” system. Do not allow any speaker lead to short to ground, as damage to the radio and/or amplifier may result.
(1) If all speakers are inoperative, check the fuses in the Integrated Power Module (IPM). If OK, go to Step 2. If not OK, repair the shorted circuit or com- ponent as required and replace the faulty fuse.
(2) Check the amplifier fuse (if equipped) in the IPM. If OK, go to Step 3. If not OK, repair the shorted circuit or component as required and replace the faulty fuse.
(3) Turn the ignition switch to the ON position. Turn the radio receiver ON. Adjust the balance and fader control controls to check the performance of each individual speaker. Note the speaker locations that are not performing correctly. Go to Step 4.
(4) Turn the radio receiver OFF. Turn the ignition OFF. Disconnect and isolate the battery negative
AUDIO
8A - 13
cable. If vehicle is not equipped with a amplifier, remove the radio receiver. If vehicle is equipped with an amplifier. disconnect wire harness connector at output side of amplifier. Go to Step 5.
(5) Check both the speaker feed (+) circuit and return (-) circuit cavities for the inoperative speaker at the radio receiver wire harness connector for con- tinuity to ground. There should be no continuity. If OK, go to Step 6. If not OK, repair the shorted speaker feed (+) and/or return (-) circuits(s) to the speaker as required.
(6) Disconnect wire harness connector at the inop- erative speaker. Check for continuity between the speaker feed (+) circuit cavities of the radio receiver wire harness connector or if equipped, the amplifier wire harness connector and the speaker wire harness connector. Repeat the check between the speaker return (-) circuit cavities of the radio receiver wire harness connector and the speaker wire harness con- nector. In each case, there should be continuity. If OK, replace the faulty speaker. If not OK, repair the open speaker feed (+) and/or return (-) circuits(s) as required.
REMOVAL
FRONT DOOR SPEAKER
(1) Disconnect and isolate the battery negative
cable.
(2) Remove front door trim panel (Refer to 23 - BODY/DOOR - FRONT/TRIM PANEL - REMOVAL).
(3) Remove speaker mounting screws (Fig. 16).
Fig.16FRONTDOORSPEAKER
(4) Disconnect electrical harness connector and
remove speaker.
AUDIO
8A - 14
SPEAKER (Continued) INSTRUMENT PANEL CENTER SPEAKERREAR CAB SIDE SPEAKER
DR
(1) Disconnect and isolate the battery negative
(1) Disconnect and isolate the battery negative
cable.
cable.
(2) Remove instrument panel top cover (Refer to 23 - BODY/INSTRUMENT PANEL/INSTRUMENT PANEL TOP COVER - REMOVAL).
(3) Remove speaker mounting screws (Fig. 17).
(2) Remove B-pillar lower trim (Refer to 23 - TRIM -
LOWER
BODY/INTERIOR/B-PILLAR REMOVAL).
(3) Remove speaker mounting screws (Fig. 19).
Fig.17INSTRUMENTPANELCENTERSPEAKER (4) Disconnect electrical harness connector and
remove speaker.
Fig.19REARCABSIDESPEAKER
(4) Disconnect electrical harness connector and
remove speaker.
INSTRUMENT PANEL END SPEAKER
REAR DOOR SPEAKER
(1) Disconnect and isolate the battery negative
(1) Disconnect and isolate the battery negative
cable.
(2) Remove instrument panel top cover (Refer to 23 - BODY/INSTRUMENT PANEL/INSTRUMENT PANEL TOP COVER - REMOVAL).
(3) Remove speaker mounting screws (Fig. 18)
cable.
(2) Remove rear door trim panel (Refer to 23 - BODY/DOORS - REAR/TRIM PANEL - REMOVAL).
(3) Remove speaker mounting screws (Fig. 20).
Fig.18INSTRUMENTPANELENDSPEAKER
(4) Disconnect electrical harness connector and
remove speaker.
Fig.20REARDOORSPEAKER
(4) Disconnect electrical harness connector and
remove speaker.
DR SPEAKER (Continued) INSTALLATION
FRONT DOOR SPEAKER
(1) Connect
electrical harness
connector
and
install speaker.
(2) Install front door trim panel (Refer to 23 - BODY/DOOR - FRONT/TRIM PANEL - INSTALLA- TION).
(3) Connect battery negative cable.
INSTRUMENT PANEL CENTER SPEAKER
(1) Connect
electrical harness
connector
and
install speaker.
(2) Install instrument panel top cover (Refer to 23
PANEL/INSTRUMENTPANEL TOP COVER - INSTALLATION).
BODY/INSTRUMENT
(3) Connect battery negative cable.
INSTRUMENT PANEL END SPEAKER
(1) Connect
install speaker.
electrical harness
connector
and
AUDIO
8A - 15
(2) Install instrument panel top cover (Refer to 23
PANEL/INSTRUMENTPANEL TOP COVER - INSTALLATION).
BODY/INSTRUMENT
(3) Connect battery negative cable.
REAR CAB SIDE SPEAKER
(1) Connect
electrical harness
connector
and
install speaker.
(2) Install B-pillar lower trim (Refer to 23 - BODY/ INTERIOR/B-PILLAR LOWER TRIM - INSTALLA- TION).
(3) Connect battery negative cable.
REAR DOOR SPEAKER
install speaker.
(1) Connect
electrical harness
connector
and
(2) Install rear door trim panel
(Refer to 23 - BODY/DOORS - REAR/TRIM PANEL - INSTALLA- TION).
(3) Connect battery negative cable.
DR
CHIME/BUZZER
8B - 1
CHIME/BUZZER
TABLE OF CONTENTS
CHIME/BUZZER
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . 1
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1DIAGNOSIS AND TESTING - CHIME
CONDITIONS . . . . . . . . . . . . . . . . . . . . . . . . . . 2
page
page
CHIME/BUZZER DESCRIPTION
The chime module is located within the instrument cluster and is not serviceable. The chime system pro- vides the driver with warning chimes for:
† Air Bag † Seat Belt † Low Fuel † Door Ajar † Low Wash † Park Brake † Over Speed † Turn Signal On † Key-In Ignition † Exterior Lamps ON † Warning Lamp Announcement † Transmission Over Temperature
OPERATION
FASTEN SEAT BELT
The seat belt reminder system uses both visual and audible signals. The Instrument Cluster moni- tors the driver seat belt buckle switch. When the ignition switch transitions from OFF to RUN and the driver seat belt has not been buckled, the Instrument Cluster will illuminate the seat belt indicator lamp and sound the chime. The system will always illumi- nate the seat belt reminder lamp for four to eight seconds when the ignition switch is turned to the ON position. The CHIME will sound during the same time interval if the driver’s seat belt is not fastened. The warning lamp will remain illuminated as long as the seat belt remains unbuckled, and the ignition switch is in the RUN position. Passenger seat belts are not connected to the system.
HEADLAMPS REMINDER
The Instrument Cluster monitors the multiplex headlamp switch. The headlamp audible warning will alert the driver that the exterior lamps have been left on. If the ignition switch is left off, the driver’s door open, and the headlamp switch is in the park
lamp or headlamp position, the chime will sound until the headlamp switch is turned off, the door is closed or the battery protection time out expires.
KEY IN IGNITION REMINDER
The Instrument Cluster monitors the ignition switch. The chime will activate if the drivers door is opened and the key is in the ignition switch, with the ignition switch in either the OFF, LOCK, or the accessory (ACC) position. The chime will continue until the key is removed from the ignition switch or the door is closed.
DOOR AJAR CHIME
The Instrument Cluster monitors the door ajar switches. A chime will sound once when the door is opened, the ignition is in RUN position and vehicle speed is present.
TURN SIGNAL ON
The Instrument Cluster monitors the multiplex multifunction switch. The instrument cluster shall remind the driver that either turn signal has been left on by a continuous chime after the turn signal indicator is left ON for 1.0 miles and the vehicle speed is 15 mph or greater.
LOW FUEL REMINDER
When the fuel
level drops to approximately 1/8
tank, the fuel symbol will light and a single chime will sound. The light will remain on until fuel is added.OVER SPEED
During any ignition ON, the Instrument Cluster maintains the most recently received speed. If the vehicle speed exceeds a preprogramed limit set in the instrument cluster it will activate a single chime.
WARNING LAMP ANNOUNCEMENT
The Instrument Cluster monitors critical engine and transmission system parameters. If any of the systems are out of their operating parameters, the instrument cluster will illuminate a lamp and acti- vate and audible chime.
CHIME/BUZZER
8B - 2
CHIME/BUZZER (Continued) LOW WASH INDICATORThe Front Control Module (FCM) monitors the washer reservoir. When the fluid is low the FCM transmits a J1850 message over the bus. The instru- ment cluster will chime and illuminate the LOW WASH indicator. The indicator will remain on until the fluid level is corrected.
AIR BAG
The Instrument Cluster monitors air bag system via the J1850 bus communications from the air bag module. The air bag module will transmit a message once per second, over the J1850 bus, as to whether the warning indicator should be on or off. The warn- ing indicator indicates a part of the air bag system is inoperative and needs to be serviced. It does not indicate that the air bag system will not deploy. If the instrument cluster does not receive a message from the air bag module for 3 consecutive seconds, the Instrument will illuminate the warning indicator.
DR
The air bag module transmits a J1850 message requesting the instrument cluster to perform a bulb check each time the ignition is turned to the on posi- tion
DIAGNOSIS AND TESTING - CHIME CONDITIONS
NOTE: The Chime/Buzzer Warning System is Diag- nosed using a DRBIIIT Scan Tool. Refer to the proper Body Diagnostic Procedures Manual.
Visually inspect the related wiring harness connec- tors. Look for broken, bent, pushed out, or corroded terminals. If any of the conditions are present, repair as necessary. If not use the DRBIIIt scan tool and the proper Body Diagnostic Procedure manual. For to Instrument complete circuit diagrams, Cluster in Wiring Systems.
refer
DR
ELECTRONIC CONTROL MODULES
8E - 1
ELECTRONIC CONTROL MODULES
TABLE OF CONTENTS
page
page
COMMUNICATION
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . 1
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2CONTROLLER ANTILOCK BRAKE
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . 3
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . 3DATA LINK CONNECTOR
DESCRIPTION - DATA LINK CONNECTOR . . . . . 3
. . . . . . 3
OPERATION - DATA LINK CONNECTORENGINE CONTROL MODULE
DESCRIPTION - ECM . . . . . . . . . . . . . . . . . . . . . 4
OPERATION - ECM . . . . . . . . . . . . . . . . . . . . . . 4
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . 5FRONT CONTROL MODULE
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . 5
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
DIAGNOSIS AND TESTING - FRONTCONTROL MODULE
. . . . . . . . . . . . . . . . . . . . 6
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . 6HEATED SEAT MODULE
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . 6
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
DIAGNOSIS AND TESTING - HEATED SEATMODULE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . 7POWERTRAIN CONTROL MODULE
DESCRIPTION
DESCRIPTION - PCM . . . . . . . . . . . . . . . . . . . 8
COMMUNICATION DESCRIPTION
The DaimlerChrysler Programmable Communica- tion Interface (PCI) data bus system is a single wire multiplex system used for vehicle communications on many DaimlerChrysler Corporation vehicles. Multi-
DESCRIPTION - MODES OF OPERATION . . . . 8
DESCRIPTION - 5 VOLT SUPPLIES . . . . . . . 10
DESCRIPTION - IGNITION CIRCUIT SENSE . 10
. . . . . . 10
DESCRIPTION - POWER GROUNDS DESCRIPTION - SENSOR RETURN . . . . . . . 10OPERATION
OPERATION - PCM . . . . . . . . . . . . . . . . . . . . 11
OPERATION - 5 VOLT SUPPLIES . . . . . . . . . 11
OPERATION - IGNITION CIRCUIT SENSE . . . 12
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . 12SENTRY KEY IMMOBILIZER MODULE
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . 13
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
STANDARD PROCEDURE - PCM/SKIMPROGRAMMING . . . . . . . . . . . . . . . . . . . . . . 14
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . 15TRANSFER CASE CONTROL MODULE
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . 15
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . 15TRANSMISSION CONTROL MODULE
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . 19
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
STANDARD PROCEDURESTANDARD PROCEDURE - TCM QUICK
LEARN. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
STANDARD PROCEDURE - DRIVE LEARN . . 21plexing is a system that enables the transmission of several messages over a single channel or circuit. All DaimlerChrysler vehicles use this principle for com- munication between various microprocessor-based electronic control modules. The PCI data bus exceeds the Society of Automotive Engineers (SAE) J1850
Standard for Class B Multiplexing.ELECTRONIC CONTROL MODULES
8E - 2
COMMUNICATION (Continued)Many of the electronic control modules in a vehicle require information from the same sensing device. In the past, if information from one sensing device was required by several controllers, a wire from each con- troller needed to be connected in parallel to that sen- sor. In addition, each controller utilizing analog sensors required an Analog/Digital (A/D) converter in order to 9read9 these sensor inputs. Multiplexing reduces wire harness complexity, sensor current loads and controller hardware because each sensing device is connected to only one controller, which reads and distributes the sensor information to the other controllers over the data bus. Also, because each controller on the data bus can access the con- troller sensor inputs to every other controller on the data bus, more function and feature capabilities are possible.
In addition to reducing wire harness complexity, component sensor current loads and controller hard- ware, multiplexing offers a diagnostic advantage. A multiplex system allows the information flowing between controllers to be monitored using a diagnos- tic scan tool. The DaimlerChrysler system allows an electronic control module to broadcast message data out onto the bus where all other electronic control modules can 9hear9 the messages that are being sent. When a module hears a message on the data bus that it requires, it relays that message to its micro- processor. Each module ignores the messages on the data bus that are being sent to other electronic con- trol modules.
OPERATION
Data exchange between modules is achieved by serial transmission of encoded data over a single wire broadcast network. The wire colors used for the PCI data bus circuits are yellow with a violet tracer, or violet with a yellow tracer, depending upon the appli- cation. The PCI data bus messages are carried over the bus in the form of Variable Pulse Width Modu- lated (VPWM) signals. The PCI data bus speed is an average 10.4 Kilo-bits per second (Kbps). By compar- ison, the prior two-wire Chrysler Collision Detection (CCD) data bus system is designed to run at 7.8125
Kbps.The voltage network used to transmit messages requires biasing and termination. Each module on the PCI data bus system provides its own biasing and termination. Each module (also referred to as a node) terminates the bus through a terminating resistor and a terminating capacitor. There are two types of nodes on the bus. The dominant node termi- nates the bus through a 1 KW resistor and a 3300 pF capacitor. The Powertrain Control Module (PCM) is the only dominant node for the PCI data bus system.
DR
A standard node terminates the bus through an 11
KW resistor and a 330 pF capacitor.The modules bias the bus when transmitting a message. The PCI bus uses low and high voltage lev- els to generate signals. Low voltage is around zero volts and the high voltage is about seven and one- half volts. The low and high voltage levels are gener- ated by means of variable-pulse width modulation to form signals of varying length. The Variable Pulse Width Modulation (VPWM) used in PCI bus messag- ing is a method in which both the state of the bus and the width of the pulse are used to encode bit information. A 9zero9 bit is defined as a short low pulse or a long high pulse. A 9one9 bit is defined as a long low pulse or a short high pulse. A low (passive) state on the bus does not necessarily mean a zero bit. It also depends upon pulse width. If the width is short, it stands for a zero bit. If the width is long, it stands for a one bit. Similarly, a high (active) state does not necessarily mean a one bit. This too depends upon pulse width. If the width is short, it stands for a one bit. If the width is long, it stands for a zero bit. In the case where there are successive zero or one data bits, both the state of the bus and the width of the pulse are changed alternately. This encoding scheme is used for two reasons. First, this ensures that only one symbol per transition and one transi- tion per symbol exists. On each transition, every transmitting module must decode the symbol on the bus and begin timing of the next symbol. Since tim- ing of the next symbol begins with the last transition detected on the bus, all of the modules are re-syn- chronized with each symbol. This ensures that there are no accumulated timing errors during PCI data bus communication.
The second reason for this encoding scheme is to guarantee that the zero bit is the dominant bit on the bus. When two modules are transmitting simul- taneously on the bus, there must be some form of arbitration to determine which module will gain con- trol. A data collision occurs when two modules are transmitting different messages at the same time. When a module is transmitting on the bus, it is read- ing the bus at the same time to ensure message integrity. When a collision is detected, the module that transmitted the one bit stops sending messages over the bus until the bus becomes idle.
Each module is capable of transmitting and receiv- ing data simultaneously. The typical PCI bus mes- sage has the following four components: † Message Header - One to three bytes in length. The header contains information identifying the mes- sage type and length, message priority, target mod- ule(s) and sending module. † Data Byte(s) - This is the actual message that
is being sent.
DR COMMUNICATION (Continued) † Cyclic Redundancy Check (CRC) Byte - This byte is used to detect errors during a message trans- mission. † In-Frame Response (IFR) byte(s)
If a response is required from the target module(s), it can be sent during this frame. This function is described in greater detail in the following paragraph.
The IFR consists of one or more bytes, which are transmitted during a message. If the sending module requires information to be received immediately, the target module(s) can send data over the bus during the original message. This allows the sending module to receive time-critical information without having to wait for the target module to access the bus. After the IFR is received, the sending module broadcasts an End of Frame (EOF) message and releases control of the bus.
The PCI data bus can be monitored using the DRBIIIt scan tool. It is possible, however, for the bus to pass all DRBIIIt tests and still be faulty if the voltage parameters are all within the specified range and false messages are being sent.
CONTROLLER ANTILOCK BRAKE DESCRIPTION
The Controler Antilock Brake (CAB) is mounted to the Hydraulic Control Unit (HCU) and operates the ABS system (Fig. 1).
ELECTRONIC CONTROL MODULES
8E - 3
OPERATION
The CAB voltage source is through the ignition switch in the RUN position. The CAB contains a self check program that illuminates the ABS warning light when a system fault is detected. Faults are stored in a diagnostic program memory and are accessible with the DRB III scan tool. ABS faults remain in memory until cleared, or until after the vehicle is started approximately 50 times. Stored faults are not erased if the battery is disconnected.
NOTE: If the CAB is being replaced with a new CAB is must be reprogrammed with the use of a DRB III.
REMOVAL
(1) Remove the negative battery cable from the
battery.
(2) Pull up on the CAB harness connector release
and remove connector.
(3) Remove the CAB mounting bolts. (4) Remove the pump connector from the CAB. (5) Remove the CAB from the HCU.
INSTALLATION
NOTE: If the CAB is being replaced with a new CAB is must be reprogrammed with the use of a DRB III.
(1) Install CAB to the HCU. (2) Install the pump connector to the CAB. (3) Install mounting bolts. Tighten to 2 N·m (16 in.
lbs.).
(4) Install the wiring harness connector to the CAB and push down on the release to secure the con- nector.
(5) Install negative battery cable to the battery.
DATA LINK CONNECTOR DESCRIPTION - DATA LINK CONNECTOR
The Data Link Connector (DLC) is located at the lower edge of the instrument panel near the steering column.
OPERATION - DATA LINK CONNECTOR
The 16–way data link connector (diagnostic scan tool connector) links the Diagnostic Readout Box (DRB) scan tool or the Mopar Diagnostic System (MDS) with the Powertrain Control Module (PCM).
Fig.1HYDRAULICCONTROLUNIT
1 - HYDRAULIC CONTROL UNIT 2 - MOUNTING BOLTS
8E - 4
ELECTRONIC CONTROL MODULES
DR
ENGINE CONTROL MODULE DESCRIPTION - ECM
The Engine Control Module (ECM) is bolted to the left side of the engine below the intake manifold (Fig. 2).
NOTE: ECM Inputs:
† Accelerator Pedal Position Sensor (APPS) Volts † APPS1 Signal — For off engine APPS † APPS2 Signal — For off engine APPS † APPS Idle Validation Switches #1 and #2
† Battery voltage † Camshaft Position Sensor (CMP) † CCD bus (+) circuits † CCD bus (-) circuits † Crankshaft Position Sensor (CKP) † Data link connection for DRB scan tool † Engine Coolant Temperature (ECT) sensor † Ground circuits † Fuel Pressure Sensor † Battery Temperature † Fan speed † Inlet Air Temperature Sensor/Pressure Sensor † Intake Air Temperature Sensor/MAP Sensor † Oil Pressure SWITCH † Power ground † Sensor return † Signal ground † Water-In-Fuel (WIF) sensorNOTE: ECM Outputs:
Fig.2DIESELECM
1 - ENGINE CONTROL MODULE (ECM) 2 - ECM MOUNTING BOLT 3 - 50-WAY CONNECTOR 4 - SUPPORT PLATE 5 - 60-WAY CONNECTOR
OPERATION - ECM
The main function of the Engine Control Module (ECM) is to electrically control the fuel system. The Powertrain Control Module (PCM) does not control the fuel system.
flashed or re-calibrated,
The ECM can adapt its programming to meet changing operating conditions. If the ECM has been replaced, the ECM must learn the Accelerator Pedal Position Sensor (APPS) idle voltage. Failure to learn this voltage may result in unnecessary diagnos- tic trouble codes. Refer to ECM Removal/Instal- lation for learning procedures.
The ECM receives input signals from various switches and sensors. Based on these inputs, the ECM regulates various engine and vehicle operations through different system components. These compo- nents are referred to as ECM Outputs. The sensors and switches that provide inputs to the ECM are considered ECM Inputs.
After inputs are received by the ECM, certain sen- sors, switches and components are controlled or reg- ulated by the ECM. These are considered ECM Outputs. These outputs are for:
† CCD bus (+) circuits † CCD bus (-) circuits † CKP and APPS outputs to the PCM † Data link connection for DRB scan tool † Five volt sensor supply † Fuel transfer (lift) pump † Intake manifold air heater relays #1 and #2 con- † Malfunction indicator lamp (Check engine lamp) † Oil Pressure Swith/warning lamp (databus) † Fuel Control Actuator † Wait-to-start warning lamp (databus) † Fan Clutch PWM † Water-In-Fuel (WIF) warning lamp (databus)
trol circuits
(databus)
REMOVAL
The Engine Control Module (ECM) is bolted to a support bracket near the fuel filter. The support bracket mounts to the block with four capscrews and vibration isolators. A ground wire is fastened to the bracket. The other end of the wire is fastened to the engine block.
(1) Record any Diagnostic Trouble Codes (DTC’s)
found in the ECM.
DR ENGINE CONTROL MODULE (Continued)
ELECTRONIC CONTROL MODULES
8E - 5
To avoid possible voltage spike damage to either the Engine Control Module ECM, ignition key must be off, and negative battery cables must be discon- nected before unplugging ECM connectors.
(2) Disconnect both negative battery cables at both
batteries.
(3) Remove the 50–way and 60–way connector bolts at the ECM. Note: Tthe connector bolt is a female allen head. As bolt is being removed, very car- fully remove connectors from the ECM.
(4) Remove five ECM mounting bolts and remove
ECM form the vehicle (Fig. 3).
Fig.3DIESELECM
1 - ENGINE CONTROL MODULE (ECM) 2 - ECM MOUNTING BOLT 3 - 50-WAY CONNECTOR 4 - SUPPORT PLATE 5 - 60-WAY CONNECTOR
INSTALLATION
Do not apply paint to ECM. Poor ground will
result.
(1) Position ECM to ECM support bracket and install five mounting bolts. Tighten bolts to 24 N·m (18 ft. lbs.).
(2) Check pin connectors in ECM and the 50–way and 60–way connectors for corrosion or damage. Repair as necessary.
(3) Clean pins in the 50–way and 60–way electri- cal connectors with a quick-dry electrical contact cleaner.
(4) Very carefully install the 50–way and 60–way
connectors to ECM. Tighten connector allen bolts.
(5) Install both negative battery cables.
(6) Turn key to ON position. Without starting engine, slowly press throttle pedal to floor and then slowly release. This step must be done (one time) to ensure accelerator pedal position sensor calibration has been learned by ECM. If not done, possible DTC’s may be set.
(7) Use DRB scan tool to erase any stored compan-
ion DTC’s from ECM.
FRONT CONTROL MODULE DESCRIPTION
The Front Control Module (FCM) is a micro con- troller based module located in the left front corner of the engine compartment. On this model the inte- grated power module must be positioned aside in order to access the front control module. The front control module mates to the power distribution cen- ter to form the Integrated Power Module (IPM). The integrated power module connects directly to the bat- tery and provides the primary means of circuit pro- tection and power distribution for all vehicle electrical systems. The front control module controls power to some of these vehicle systems electrical and electromechanical loads based on inputs received from hard wired switch inputs and data received on the PCI bus circuit (J1850).
For information on the Integrated Power Mod- ule Refer to the Power Distribution Section of the service manual.
OPERATION
As messages are sent over the PCI bus circuit, the front control module reads these messages and con- trols power to some of the vehicles electrical systems by completing the circuit to ground (low side driver) or completing the circuit to 12 volt power (high side driver). The following functions are Controlled by the Front Control Module: † Headlamp Power with Voltage Regulation † Windshield Wiper “ON/OFF” Relay Actuation † Windshield Wiper “HI/LO” Relay Actuation † Windshield Washer Pump Motor † Fog Lamp Relay Actuation † Park Lamp Relay Actuation † Horn Relay Actuation The following inputs are Received/Monitored by † B+ Connection Detection † Power Ground † Ambient Temperature Sensing † Ignition Switch Run † Washer Fluid Level Switch † Windshield Wiper Park Switch † PCI Bus Circuit
the Front Control Module:
ELECTRONIC CONTROL MODULES
8E - 6
FRONT CONTROL MODULE (Continued) DIAGNOSIS AND TESTING - FRONT CONTROL MODULEThe front control module is a printed circuit board based module with a on-board micro-processor. The front control module interfaces with other electronic modules in the vehicle via the Programmable Com- munications Interface (PCI) data bus (J1850). In order to obtain conclusive testing the Programmable Communications Interface (PCI) data bus network and all of the electronic modules that provide inputs to, or receive outputs from the front control module must be checked. All PCI (J1850) communication faults must be resolved prior to further diagnosing any front control module related issues.
The front control module was designed to be diag- nosed with an appropriate diagnostic scan tool, such as the DRB IIIt. The most reliable, efficient, and accurate means to diagnose the front control module requires the use of a DRB IIIt scan tool and the proper Body Diagnostic Procedures manual.
Before any testing of the front control module is attempted, the battery should be fully charged and all wire harness and ground connections inspected around the affected areas on the vehicle.
REMOVAL
(1) Disconnect the positive and negative battery
cables from the battery.
(2) Partially remove the integrated power module from the engine compartment (Refer to 8 - ELECTRI- CAL/POWER DISTRIBUTION/INTEGRATED POWER MODULE - REMOVAL).
(3) Remove the front control module retaining
screws.
(4) Using both hands, pull the front control module straight from the integrated power module assembly to disconnect the 49-way electrical connector and remove the front control module from the vehicle.
INSTALLATION
(1) Install the front control module on the inte- grated power module assembly by pushing the 49-way electrical connector straight in.
(2) Install
the front
control module retaining
screws. Torque the screws to 7 in. lbs.
(3) Install the integrated power module (Refer to 8
ELECTRICAL/POWER DISTRIBUTION/INTE-GRATED POWER MODULE - INSTALLATION).
(4) Connect
the positive and negative battery
cables.
DR
HEATED SEAT MODULE DESCRIPTION
Fig.4HeatedSeatModule
1 - MOUNTING TABS (NOT USED ON DR) 2 - HEATED SEAT MODULE 3 - ELECTRICAL CONNECTOR RECEPTACLE
The heated seat module is also known as the Seat Heat Interface Module. The heated seat module (Fig. 4) is located under the drivers front seat cushion, where it is secured to a mounting bracket. The heated seat module has a single connector receptacle that allows the module to be connected to all of the required inputs and outputs through the seat wire harness.
The heated seat module is an electronic micropro- cessor controlled device designed and programmed to use inputs from the battery, the two heated seat switches and the two heated seat sensors to operate and control the heated seat elements in both front seats and the two heated seat indicator lamp Light- Emitting Diodes (LEDs) in each heated seat switch. The heated seat module is also programmed to per- form self-diagnosis of certain heated seat system functions and provide feedback of that diagnosis through the heated seat switch indicator lamps.
The heated seat module cannot be repaired. If the heated seat module is damaged or faulty, the entire module must be replaced.
OPERATION
The heated seat module operates on fused battery current received from the integrated power module. Inputs to the module include a resistor multiplexed heated seat switch request circuit for each of the two heated seat switches and the heated seat sensor inputs from the seat cushions of each front seat. In response to those inputs the heated seat module con- trols battery current feeds to the heated seat ele-
DR HEATED SEAT MODULE (Continued)
ELECTRONIC CONTROL MODULES
8E - 7
ments and sensors, and controls the ground for the heated seat switch indicator lamps.
When a heated seat switch (Driver or Passenger) is depressed a signal is received by the heated seat module, the module energizes the proper indicator LED (Low or High) in the switch by grounding the indicator lamp circuit to indicate that the heated seat system is operating. At the same time, the heated seat module energizes the selected heated seat sensor circuit and the sensor provides the module with an input the selected seat cushion.
indicating the surface temperature of
The Low heat set point is about 36° C (96.8° F), and the High heat set point is about 42° C (107.6° F). If the seat cushion surface temperature input is below the temperature set point for the selected tem- perature setting, the heated seat module energizes an N-channel Field Effect Transistor (N-FET) within the module which energizes the heated seat elements in the selected seat cushion and back. When the sen- sor input to the module indicates the correct temper- ature set point has been achieved, the module de-energizes the heated seat elements. The heated seat module will continue to cycle the N-FET as needed to maintain the selected temperature set point.
the N-FET which de-energizes
If the heated seat module detects a heated seat sensor value input that is out of range or a shorted or open heated seat element circuit, it will notify the vehicle operator or the repair technician of this con- dition by flashing the High and/or Low indicator lamps in the affected heated seat switch. Refer to Diagnosis and Testing Heated Seat System in Heated Systems for flashing LED diagnosis and test- ing procedures. Refer to Diagnosis and Testing Heated Seat Module in this section for heated seat module diagnosis and testing procedures.
DIAGNOSIS AND TESTING - HEATED SEAT MODULE
If a heated seat fails to heat and one or both of the indicator lamps on a heated seat switch flash, refer to Diagnosis and Testing Heated Seat System in Heated Seats for the location of flashing LED heated seat system diagnosis and testing procedures. If a heated seat heats but one or both indicator lamps on the heated seat switch fail to operate, test the heated to Diagnosis and Testing seat Heated Seat Switch in Heated Seats for heated seat switch diagnosis and testing procedures. If the heated seat switch checks OK, proceed as follows.
switch. Refer
(1) Check the heated seat element (Refer to 8 - SEAT
ELECTRICAL/HEATED SEATS/HEATED ELEMENT - DIAGNOSIS AND TESTING).
(2) Check the heated seat sensor (Refer to 8 - SEAT
ELECTRICAL/HEATED SENSOR - DIAGNOSIS AND TESTING).
SEATS/HEATED
(3) Check the heated seat switch (Refer to 8 - ELECTRICAL/HEATED SEATS/DRIVER HEATED SEAT SWITCH - DIAGNOSIS AND TESTING).
NOTE: Refer to Wiring for the location of complete heated seat system wiring diagrams and connector pin-out information.
(4) Using a voltmeter, backprobe the appropriate heated seat module connector, do not disconnect. Check for voltage at the appropriate pin cavities. 12v should be present. If OK go to Step 5, if Not, Repair the open or shorted voltage supply circuit as required.
(5) Using a ohmmeter, backprobe the appropriate heated seat module connector, do not disconnect. Check for proper continuity to ground on the ground pin cavities. Continuity should be present. If OK replace the heated seat module with a known good unit and retest system, if Not OK, Repair the open or shorted ground circuit as required.
REMOVAL
(1) Position the driver seat to the full rearward
and inclined position.
(2) Working under the driver front seat, remove the two heated seat module retaining screws. Due to the fact that the retaining screws are installed with the seat cushion pan removed, a small right angle screwdriver will be required to access and remove the screws.
(3) Disconnect the seat wire harness connector from the connector receptacle on the back of the heated seat module. Depress the connector retaining tab and pull straight apart.
(4) Remove the heated seat module from under the
front seat.
INSTALLATION
front seat.
(1) Position the heated seat module under the
(2) Connect the seat wire harness connector on the connector receptacle on the back of the heated seat module.
(3) Working under the driver front seat, install the
heated seat module retaining screws.
(4) Re-position the driver seat.
8E - 8
ELECTRONIC CONTROL MODULES
DR
POWERTRAIN CONTROL MODULE
DESCRIPTION
DESCRIPTION - PCM
The Powertrain Control Module (PCM) is located in the right-rear section of the engine compartment under the cowl (Fig. 5).
Two different PCM’s are used (JTEC and NGC). These can be easily identified. JTEC’s use three 32–way connectors, NGC’s use four 38–way connectors
Fig.5POWERTRAINCONTROLMODULE(PCM)
LOCATION
1 - COWL GRILL 2 - PCM 3 - COWL (RIGHT-REAR)
DESCRIPTION - MODES OF OPERATION
As input signals to the Powertrain Control Module (PCM) change, the PCM adjusts its response to the output devices. For example, the PCM must calculate different injector pulse width and ignition timing for idle than it does for wide open throttle (WOT).
The PCM will operate in two different modes:
Open Loop and Closed Loop.
During Open Loop modes, the PCM receives input signals and responds only according to preset PCM programming. Input from the oxygen (O2S) sensors is not monitored during Open Loop modes.
During Closed Loop modes, the PCM will monitor the oxygen (O2S) sensors input. This input indicates to the PCM whether or not the calculated injector pulse width results in the ideal air-fuel ratio. This ratio is 14.7 parts air-to-1 part fuel. By monitoring the exhaust oxygen content through the O2S sensor, the PCM can fine tune the injector pulse width. This is done to achieve optimum fuel economy combined with low emission engine performance.
of operation:
The fuel injection system has the following modes † Ignition switch ON † Engine start-up (crank) † Engine warm-up † Idle † Cruise † Acceleration † Deceleration † Wide open throttle (WOT) † Ignition switch OFF The ignition switch On, engine start-up (crank), engine warm-up, acceleration, deceleration and wide open throttle modes are Open Loop modes. The idle and cruise modes, (with the engine at operating tem- perature) are Closed Loop modes.
IGNITION SWITCH (KEY-ON) MODE
This is an Open Loop mode. When the fuel system is activated by the ignition switch, the following actions occur: † The PCM pre-positions the idle air control (IAC) motor.† The PCM determines atmospheric air pressure from the MAP sensor input to determine basic fuel strategy. † The PCM monitors the engine coolant tempera- ture sensor input. The PCM modifies fuel strategy based on this input. † Intake manifold air temperature sensor input is † Throttle position sensor (TPS) is monitored. † The auto shutdown (ASD) relay is energized by † The fuel pump is energized through the fuel pump relay by the PCM. The fuel pump will operate for approximately three seconds unless the engine is operating or the starter motor is engaged. † The O2S sensor heater element is energized via the ASD or O2S heater relay. The O2S sensor input is not used by the PCM to calibrate air-fuel ratio dur- ing this mode of operation.
the PCM for approximately three seconds.
monitored.
ENGINE START-UP MODE
This is an Open Loop mode. The following actions
occur when the starter motor is engaged.
The PCM receives inputs from:
DR POWERTRAIN CONTROL MODULE (Continued) † Battery voltage † Engine coolant temperature sensor † Crankshaft position sensor † Intake manifold air temperature sensor † Manifold absolute pressure (MAP) sensor † Throttle position sensor (TPS) † Camshaft position sensor signal The PCM monitors the crankshaft position sensor. If the PCM does not receive a crankshaft position sensor signal within 3 seconds of cranking the engine, it will shut down the fuel injection system.
The fuel pump is activated by the PCM through
the fuel pump relay.
Voltage is applied to the fuel injectors with the ASD relay via the PCM. The PCM will then control the injection sequence and injector pulse width by turning the ground circuit to each individual injector on and off.
The PCM determines the proper ignition timing according to input received from the crankshaft posi- tion sensor.
ENGINE WARM-UP MODE
trans. only)
up, the PCM receives inputs from:
This is an Open Loop mode. During engine warm- † Battery voltage † Crankshaft position sensor † Engine coolant temperature sensor † Intake manifold air temperature sensor † Manifold absolute pressure (MAP) sensor † Throttle position sensor (TPS) † Camshaft position sensor signal † Park/neutral switch (gear indicator signal—auto. † Air conditioning select signal (if equipped) † Air conditioning request signal (if equipped) Based on these inputs the following occurs: † Voltage is applied to the fuel injectors with the ASD relay via the PCM. The PCM will then control the injection sequence and injector pulse width by turning the ground circuit to each individual injector on and off. † The PCM adjusts engine idle speed through the idle air control (IAC) motor and adjusts ignition tim- ing.† The PCM operates the A/C compressor clutch through the A/C compressor clutch relay. This is done if A/C has been selected by the vehicle operator and specified pressures are met at the high and low–pres- sure A/C switches. Refer to Heating and Air Condi- tioning for additional information. † When engine has reached operating tempera- ture, the PCM will begin monitoring O2S sensor input. The system will then leave the warm-up mode and go into closed loop operation.
ELECTRONIC CONTROL MODULES
8E - 9
IDLE MODE
trans. only)
When the engine is at operating temperature, this is a Closed Loop mode. At idle speed, the PCM receives inputs from:
† Air conditioning select signal (if equipped) † Air conditioning request signal (if equipped) † Battery voltage † Crankshaft position sensor † Engine coolant temperature sensor † Intake manifold air temperature sensor † Manifold absolute pressure (MAP) sensor † Throttle position sensor (TPS) † Camshaft position sensor signal † Battery voltage † Park/neutral switch (gear indicator signal—auto. † Oxygen sensors Based on these inputs, the following occurs: † Voltage is applied to the fuel injectors with the ASD relay via the PCM. The PCM will then control injection sequence and injector pulse width by turn- ing the ground circuit to each individual injector on and off. † The PCM monitors the O2S sensor input and adjusts air-fuel ratio by varying injector pulse width. It also adjusts engine idle speed through the idle air control (IAC) motor. † The PCM adjusts ignition timing by increasing † The PCM operates the A/C compressor clutch through the A/C compressor clutch relay. This is done if A/C has been selected by the vehicle operator and specified pressures are met at the high and low–pres- sure A/C switches. Refer to Heating and Air Condi- tioning for additional information.
and decreasing spark advance.
CRUISE MODE
When the engine is at operating temperature, this is a Closed Loop mode. At cruising speed, the PCM receives inputs from:
† Air conditioning select signal (if equipped) † Air conditioning request signal (if equipped) † Battery voltage † Engine coolant temperature sensor † Crankshaft position sensor † Intake manifold air temperature sensor † Manifold absolute pressure (MAP) sensor † Throttle position sensor (TPS) † Camshaft position sensor signal † Park/neutral switch (gear indicator signal—auto. † Oxygen (O2S) sensors Based on these inputs, the following occurs: † Voltage is applied to the fuel injectors with the ASD relay via the PCM. The PCM will then adjust
trans. only)
ELECTRONIC CONTROL MODULES
8E - 10
POWERTRAIN CONTROL MODULE (Continued)DR
the injector pulse width by turning the ground circuit to each individual injector on and off. † The PCM monitors the O2S sensor input and adjusts air-fuel ratio. It also adjusts engine idle speed through the idle air control (IAC) motor. † The PCM adjusts ignition timing by turning the ground path to the coil(s) on and off. † The PCM operates the A/C compressor clutch through the clutch relay. This happens if A/C has been selected by the vehicle operator and requested by the A/C thermostat.
ACCELERATION MODE
This is an Open Loop mode. The PCM recognizes an abrupt increase in throttle position or MAP pres- sure as a demand for increased engine output and vehicle acceleration. The PCM increases injector pulse width in response to increased throttle opening.
DECELERATION MODE
When the engine is at operating temperature, this is an Open Loop mode. During hard deceleration, the PCM receives the following inputs.
† Air conditioning select signal (if equipped) † Air conditioning request signal (if equipped) † Battery voltage † Engine coolant temperature sensor † Crankshaft position sensor † Intake manifold air temperature sensor † Manifold absolute pressure (MAP) sensor † Throttle position sensor (TPS) † Camshaft position sensor signal † Park/neutral switch (gear indicator signal—auto. † Vehicle speed If the vehicle is under hard deceleration with the proper rpm and closed throttle conditions, the PCM will ignore the oxygen sensor input signal. The PCM will enter a fuel cut-off strategy in which it will not supply a ground to the injectors. If a hard decelera- tion does not exist, the PCM will determine the proper injector pulse width and continue injection.
trans. only)
Based on the above inputs, the PCM will adjust engine idle speed through the idle air control (IAC) motor.
The PCM adjusts ignition timing by turning the
ground path to the coil on and off.
WIDE OPEN THROTTLE MODE
This is an Open Loop mode. During wide open throttle operation, the PCM receives the following inputs.
† Battery voltage † Crankshaft position sensor † Engine coolant temperature sensor † Intake manifold air temperature sensor † Manifold absolute pressure (MAP) sensor
occurs:
† Throttle position sensor (TPS) † Camshaft position sensor signal During wide open throttle conditions, the following † Voltage is applied to the fuel injectors with the ASD relay via the PCM. The PCM will then control the injection sequence and injector pulse width by turning the ground circuit to each individual injector on and off. The PCM ignores the oxygen sensor input signal and provides a predetermined amount of addi- tional fuel. This is done by adjusting injector pulse width.† The PCM adjusts ignition timing by turning the ground path to the coil(s) on and off.
IGNITION SWITCH OFF MODE
When ignition switch is turned to OFF position, the PCM stops operating the injectors, ignition coil, ASD relay and fuel pump relay.
DESCRIPTION - 5 VOLT SUPPLIES
Two different Powertrain Control Module (PCM) five volt supply circuits are used; primary and sec- ondary.
DESCRIPTION - IGNITION CIRCUIT SENSE
This circuit ties the ignition switch to the Power-
train Control Module (PCM).
DESCRIPTION - POWER GROUNDS
The Powertrain Control Module (PCM) has 2 main grounds. Both of these grounds are referred to as power grounds. All of the high-current, noisy, electri- cal devices are connected to these grounds as well as all of the sensor returns. The sensor return comes into the sensor return circuit, passes through noise suppression, and is then connected to the power ground.
cuits for the following PCM loads:
The power ground is used to control ground cir- † Generator field winding † Fuel injectors † Ignition coil(s) † Certain relays/solenoids † Certain sensors
DESCRIPTION - SENSOR RETURN
The Sensor Return circuits are internal to the Pow-
ertrain Control Module (PCM).
Sensor Return provides a low–noise ground refer- ence for all engine control system sensors. Refer to Power Grounds for more information.
DR POWERTRAIN CONTROL MODULE (Continued) OPERATION
OPERATION - PCM
The PCM operates the fuel system. The PCM is a pre-programmed, triple microprocessor digital com- puter. It regulates ignition timing, air-fuel ratio, emission control devices, charging system, certain transmission features, speed control, air conditioning compressor clutch engagement and idle speed. The PCM can adapt its programming to meet changing operating conditions.
The PCM receives input signals from various switches and sensors. Based on these inputs, the PCM regulates various engine and vehicle operations through different system components. These compo- nents are referred to as Powertrain Control Module (PCM) Outputs. The sensors and switches that pro- vide inputs to the PCM are considered Powertrain Control Module (PCM) Inputs.
The PCM adjusts ignition timing based upon inputs it receives from sensors that react to: engine rpm, manifold absolute pressure, engine coolant tem- perature, throttle position, transmission gear selec- tion (automatic transmission), vehicle speed, power steering pump pressure, and the brake switch.
The PCM adjusts idle speed based on inputs it receives from sensors that react to: throttle position, vehicle speed, transmission gear selection, engine coolant temperature and from inputs it receives from the air conditioning clutch switch and brake switch. Based on inputs that it receives, the PCM adjusts ignition coil dwell. The PCM also adjusts the gener- ator charge rate through control of the generator field and provides speed control operation.
NOTE: PCM Inputs:
† ABS module (if equipped) † A/C request (if equipped with factory A/C) † A/C select (if equipped with factory A/C) † A/C pressure transducer † Auto shutdown (ASD) sense † Battery temperature sensor † Battery voltage † Brake switch † J1850 bus (+) circuits † J1850 bus (-) circuits † Camshaft position sensor signal † Crankshaft position sensor † Data link connection for DRB scan tool † EATX module (if equipped) † Engine coolant temperature sensor † Fuel level (through J1850 circuitry) † Generator (battery voltage) output † Ignition circuit sense (ignition switch in on/off/ crank/run position)
ELECTRONIC CONTROL MODULES
8E - 11
† Intake manifold air temperature sensor † Knock sensors (2 on 3.7L engine) † Leak detection pump (switch) sense (if equipped) † Manifold absolute pressure (MAP) sensor † Oil pressure † Oxygen sensors † Park/neutral switch (auto. trans. only) † Power ground † Power steering pressure switch (if equipped) † Sensor return † Signal ground † Speed control multiplexed single wire input † Throttle position sensor † Transfer case switch (4WD range position) † Vehicle speed signal
NOTE: PCM Outputs: † A/C clutch relay † Auto shutdown (ASD) relay † J1850 bus (+/-) circuits for: speedometer, voltme- ter, fuel gauge, oil pressure gauge/lamp, engine temp. gauge and speed control warn. lamp
† Data link connection for DRB scan tool † EGR valve control solenoid (if equipped) † EVAP canister purge solenoid † Five volt sensor supply (primary) † Five volt sensor supply (secondary) † Fuel injectors † Fuel pump relay † Generator field driver (-) † Generator field driver (+) † Idle air control (IAC) motor † Ignition coil(s) † Leak detection pump (if equipped) † Malfunction indicator lamp (Check engine lamp). † Oxygen sensor heater relays † Oxygen sensors (pulse width modulated) † Radiator cooling fan relay (pulse width modu- lated)† Speed control vacuum solenoid † Speed control vent solenoid † Tachometer (if equipped). Driven through J1850
† Transmission convertor clutch circuit. DrivenDriven through J1850 circuits.
circuits.
through J1850 circuits.
OPERATION - 5 VOLT SUPPLIES
Crankshaft Position (CKP) sensor.
Primary 5–volt supply: † supplies the required 5 volt power source to the † supplies the required 5 volt power source to the † supplies a reference voltage for the Manifold
Camshaft Position (CMP) sensor.
Absolute Pressure (MAP) sensor.
DR
ELECTRONIC CONTROL MODULES
8E - 12
POWERTRAIN CONTROL MODULE (Continued) † supplies a reference voltage for the Throttle Position Sensor (TPS) sensor. Secondary 5–volt supply: † supplies the required 5 volt power source to the oil pressure sensor. † supplies the required 5 volt power source for the Vehicle Speed Sensor (VSS) (if equipped). † supplies the 5 volt power source to the transmis- sion pressure sensor (certain automatic transmis- sions).OPERATION - IGNITION CIRCUIT SENSE
The ignition circuit sense input tells the PCM the
ignition switch has energized the ignition circuit.
Battery voltage is also supplied to the PCM through the ignition switch when the ignition is in the RUN or START position. This is referred to as the 9ignition sense9 circuit and is used to 9wake up9
the PCM. Voltage on the ignition input can be as low as 6 volts and the PCM will still function. Voltage is supplied to this circuit to power the PCM’s 8-volt reg- ulator and to allow the PCM to perform fuel, ignition and emissions control functions.REMOVAL
USE THE DRB SCAN TOOL TO REPROGRAM THE NEW POWERTRAIN CONTROL MODULE (PCM) WITH THE VEHICLES ORIGINAL IDEN- TIFICATION NUMBER (VIN) AND THE VEHI- CLES ORIGINAL MILEAGE. IF THIS STEP IS NOT DONE, A DIAGNOSTIC TROUBLE CODE (DTC) MAY BE SET.
The PCM is located in the engine compartment
attached to the dash panel (Fig. 6).
To avoid possible voltage spike damage to the PCM, ignition key must be off, and negative battery cable must be disconnected before unplugging PCM connectors.
(1) Disconnect negative battery cable at battery. (2) Remove cover over electrical connectors. Cover
snaps onto PCM.
(3) Carefully unplug the three 32–way connectors (four 38–way connectors if equipped with NGC) from PCM (Fig. 7).
(4) Remove three PCM mounting bolts (Fig. 7) and
remove PCM from vehicle.
INSTALLATION
USE THE DRB SCAN TOOL TO REPROGRAM THE NEW POWERTRAIN CONTROL MODULE (PCM) WITH THE VEHICLES ORIGINAL IDEN- TIFICATION NUMBER (VIN) AND THE VEHI- CLES ORIGINAL MILEAGE. IF THIS STEP IS NOT DONE, A DIAGNOSTIC TROUBLE CODE (DTC) MAY BE SET.
(1) Install PCM and 3 mounting bolts to vehicle.
Fig.6PCMLOCATION
1 - COWL GRILL 2 - PCM 3 - COWL (RIGHT-REAR)
Fig.7PCMREMOVAL/INSTALLATION
1 - THREE 32-WAY CONNECTORS WITH JTEC (FOUR 38-WAY CONNECTORS WITH NGC) 2 - PCM MOUNTING BRACKET 3 - PCM 4 - PCM MOUNTING SCREWS (3)
DR POWERTRAIN CONTROL MODULE (Continued)
ELECTRONIC CONTROL MODULES
8E - 13
(2) Tighten bolts. Refer to torque specifications. (3) Check pin connectors in the PCM and the three 32–way if equipped with NGC) for corrosion or damage. Also, the pin heights in connectors should all be same. Repair as necessary before installing connectors.
(four 38–way
connectors
connectors
(4) Install three 32–way connectors (four 38–way
connectors if equipped with NGC).
(5) Install cover over electrical connectors. Cover
snaps onto PCM.
(6) Install negative battery cable. (7) Use the DRB scan tool to reprogram new PCM with vehicles original Vehicle Identification Number (VIN) and original vehicle mileage.
SENTRY KEY IMMOBILIZER MODULE DESCRIPTION
The Sentry Key Immobilizer Module (SKIM) con- tains a Radio Frequency (RF) transceiver and a cen- tral processing unit, which includes the Sentry Key Immobilizer System (SKIS) program logic. The SKIS programming enables the SKIM to program and retain in memory the codes of at least two, but no more than eight electronically coded Sentry Key transponders. The SKIS programming also enables the SKIM to communicate over the Programmable Communication Interface (PCI) bus network with the Powertrain Control Module the DRBIIIt scan tool.
(PCM), and/or
OPERATION
The SKIM transmits and receives RF signals through a tuned antenna enclosed within a molded plastic ring that is integral to the SKIM housing. When the SKIM is properly installed on the steering column, the antenna ring is oriented around the igni- tion lock cylinder housing. This antenna ring must be located within eight millimeters (0.31 inches) of the Sentry Key in order to ensure proper RF communica- tion between the SKIM and the Sentry Key tran- sponder.
For added system security, each SKIM is pro- grammed with a unique “Secret Key” code and a security code. The SKIM keeps the “Secret Key” code in memory. The SKIM also sends the “Secret Key” code to each of the programmed Sentry Key tran- sponders. The security code is used by the assembly plant to access the SKIS for initialization, or by the dealer technician to access the system for service. The SKIM also stores in its memory the Vehicle Identification Number (VIN), which it learns through a PCI bus message from the PCM during initializa- tion.
The SKIM and the PCM both use software that includes a rolling code algorithm strategy, which helps to reduce the possibility of unauthorized SKIS disarming. The rolling code algorithm ensures secu- rity by preventing an override of the SKIS through the unauthorized substitution of the SKIM or the PCM. However, the use of this strategy also means that replacement of either the SKIM or the PCM units will require a system initialization procedure to restore system operation.
When the ignition switch is turned to the ON or START positions, the SKIM transmits an RF signal to excite the Sentry Key transponder. The SKIM then listens for a return RF signal from the transponder of the Sentry Key that is inserted in the ignition lock cylinder. If the SKIM receives an RF signal with valid “Secret Key” and transponder identification codes, the SKIM sends a “valid key” message to the PCM over the PCI bus. If the SKIM receives an invalid RF signal or no response, it sends “invalid key” messages to the PCM. The PCM will enable or disable engine operation based upon the status of the SKIM messages.
The SKIM also sends messages to the Instrument Cluster which controls the VTSS indicator LED. The SKIM sends messages to the Instrument Cluster to turn the LED on for about three seconds when the ignition switch is turned to the ON position as a bulb test. After completion of the bulb test, the SKIM sends bus messages to keep the LED off for a dura- tion of about one second. Then the SKIM sends mes- sages to turn the LED on or off based upon the results of the SKIS self-tests. If the VTSS indicator LED comes on and stays on after the bulb test, it indicates that the SKIM has detected a system mal- function and/or that the SKIS has become inopera- tive.
If the SKIM detects an invalid key when the igni- tion switch is turned to the ON position, it sends messages to flash the VTSS indicator LED. The SKIM can also send messages to flash the LED as an indication to the customer that the SKIS has been placed in it’s “Customer Learn” programming mode. See Sentry Key Immobilizer System Transponder Programming in this section for more information on the “Customer Learn” programming mode.
For diagnosis or initialization of the SKIM and the PCM, a DRBIIIt scan tool and the proper Powertrain Diagnostic Procedures manual are required. The SKIM cannot be repaired and, if faulty or damaged, the unit must be replaced.
ELECTRONIC CONTROL MODULES
8E - 14
SENTRY KEY IMMOBILIZER MODULE (Continued) STANDARD PROCEDURE - PCM/SKIM PROGRAMMINGNOTE: There are two procedures for transfering the secret key to the SKIM: † When ONLY the SKIM module is replaced, the secret key is transfered from the PCM to the SKIM. The ORGINAL KEYS may then be programmed to the SKIM. † When ONLY the PCM is replaced, then the secret key is transfered from the SKIM to the PCM. The ORGINAL KEYS may be used. † When BOTH the SKIM and the PCM are replaced the secret key is transferred from the SKIM to the PCM, and NEW KEYS must be pro- grammed.
NOTE: Before replacing the Powertrain Control Module (PCM) for a failed driver, control circuit, or ground circuit, be sure to check the related compo- nent/circuit integrity for failures not detected due to a double fault in the circuit. Most PCM driver/con- trol circuit failures are caused by internal compo- nent failures (i.e. relay and solenoids) and shorted circuits (i.e. pull-ups, drivers and switched circuits). These failures are difficult to detect when a double fault has occurred and only one Diagnostic Trouble Code (DTC) has set.
When a PCM (SBEC) and the Sentry Key Immobi- lizer Module (SKIM) are replaced at the same time perform the following steps in order: (1) Program the new PCM (SBEC). (2) Program the new SKIM. (3) Replace all ignition keys and program them to
the new SKIM.
PROGRAMMING THE PCM (SBEC)
The Sentry Key Immobilizer System (SKIS) Secret Key is an ID code that is unique to each SKIM. This code is programmed and stored in the SKIM, PCM and transponder chip (ignition keys). When replacing the PCM it is necessary to program the secret key into the new PCM using the DRBIIIt scan tool. Per- form the following steps to program the secret key into the PCM.
(1) Turn the ignition switch on (transmission in
park/neutral).
(2) Use the DRBIIIt scan tool and select THEFT
ALARM, SKIM then MISCELLANEOUS.
(3) Select PCM REPLACED (GAS ENGINE). (4) Enter secured access mode by entering the
vehicle four-digit PIN.
(5) Select ENTER to update PCM VIN.
DR
NOTE: If three attempts are made to enter secure access mode using an incorrect PIN, secured access mode will be locked out for one hour. To exit this lockout mode, turn the ignition to the RUN position for one hour then enter the correct PIN. (Ensure all accessories are turned OFF. Also moni- tor the battery state and connect a battery charger if necessary).
(6) Press ENTER to transfer the secret key (the
SKIM will send the secret key to the PCM).
(7) Press Page Back to get to the Select System menu and select ENGINE, MISCELLANEOUS, and SRI MEMORY CHECK.
(8) The DRBIIIt scan tool will ask, Is odometer reading between XX and XX? Select the YES or NO button on the DRB IIIt scan tool. If NO is selected, the DRBIIIt scan tool will read, Enter odometer Reading
. Enter the odometer reading from the instrument cluster and press ENTER. PROGRAMMING THE SKIM
(1) Turn the ignition switch on (transmission in
park/neutral).
(2) Use the DRBIIIt scan tool and select THEFT
ALARM, SKIM then MISCELLANEOUS.
(3) Select SKIM REPLACED (GAS ENGINE). (4) Program the vehicle four-digit PIN into SKIM. (5) Select COUNTRY CODE and enter the correct
country.
NOTE: Be sure to enter the correct country code. If the incorrect country code is programmed into the SKIM, the SKIM must be replaced.
(6) Select YES to update the VIN (the SKIM will
learn the VIN from the PCM).
(7) Press ENTER to transfer the secret key (the PCM will send the secret key information to the SKIM).
(8) Program ignition keys to the SKIM.
NOTE: If the PCM and the SKIM are replaced at the same time, all vehicle keys will need to be replaced and programmed to the new SKIM.
PROGRAMMING IGNITION KEYS TO THE SKIM
(1) Turn the ignition switch on (transmission in
park/neutral).
(2) Use the DRBIIIt scan tool and select THEFT
ALARM, SKIM then MISCELLANEOUS.
(3) Select PROGRAM IGNITION KEY’S. (4) Enter secured access mode by entering the
vehicle four-digit PIN.
DR SENTRY KEY IMMOBILIZER MODULE (Continued)
ELECTRONIC CONTROL MODULES
8E - 15
NOTE: A maximum of eight keys can be learned to each SKIM. Once a key is learned to a SKIM, it (the key) cannot be transferred to another vehicle.
(5) If ignition key programming is unsuccessful, the DRBIIIt scan tool will display one of the follow- ing messages:
(a) Programming Not Attempted - The DRBIIIt scan tool attempts to read the programmed key status and there are no keys programmed into SKIM memory.
(b) Programming Key Failed (Possible Used Key From Wrong Vehicle) - SKIM is unable to program key due to one of the following: † Faulty ignition key transponder. † Ignition key is programmed to another vehicle. (c) 8 Keys Already Learned, Programming Not
Done - SKIM transponder ID memory is full. (6) Obtain ignition keys to be programmed from
customer (8 keys maximum).
(7) Using the DRBIIIt scan tool, erase all ignition keys by selecting MISCELLANEOUS and ERASE ALL CURRENT IGN. KEYS.
(8) Program all ignition keys. Learned Key In Ignition - Ignition key transponder
ID is currently programmed in SKIM memory.
REMOVAL
cable.
(1) Disconnect and isolate the battery negative
(2) Remove the steering column upper and lower to Steering, Column, Shroud,
shrouds. Refer Removal.
(3) Disconnect the steering column wire harness connector from the Sentry Key Immobilizer Module (SKIM)
(4) Remove the screw securing the SKIM module
to the steering column (Fig. 8).
