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Upstream Sensor - Federal Emissions Pack- age : The upstream sensor (1/1) provides an input voltage to the PCM. The input tells the PCM the oxy- gen content of the exhaust gas. The PCM uses this information to fine tune fuel delivery to maintain the correct oxygen content at the downstream oxygen sensor. The PCM will change the air/fuel ratio until the upstream sensor inputs a voltage that the PCM has determined will make the downstream sensor output (oxygen content) correct.
The upstream oxygen sensor also provides an input
to determine catalytic convertor efficiency.
DR
Refer to (Fig. 39) or (Fig. 40) for typical O2S (oxy-
gen sensor) locations.
WARNING: THE EXHAUST MANIFOLD, EXHAUST PIPES AND CATALYTIC CONVERTER BECOME VERY HOT DURING ENGINE OPERATION. ALLOW ENGINE TO COOL BEFORE REMOVING OXYGEN SENSOR.
(1) Raise and support vehicle. (2) Disconnect wire connector from O2S sensor.
CAUTION: When disconnecting sensor electrical connector, do not pull directly on wire going into sensor.
(3) Remove O2S sensor with an oxygen sensor
removal and installation tool.
(4) Clean threads in exhaust pipe using appropri-
ate tap.
Fig.39O2SENSORSYSTEM-WITH4SENSORS
FUEL INJECTION - GAS
14 - 44
OXYGEN SENSOR (Continued)Downstream Sensor
- Federal Emissions Package : The downstream oxygen sensor (1/2) is also used to determine the correct air-fuel ratio. As the oxygen content changes at the downstream sen- sor, the PCM calculates how much air-fuel ratio change is required. The PCM then looks at the upstream oxygen sensor voltage and changes fuel delivery until the upstream sensor voltage changes enough to correct the downstream sensor voltage (oxygen content).
The downstream oxygen sensor also provides an
input to determine catalytic convertor efficiency.
Upstream Sensors
- California Emissions Package : Two upstream sensors are used (1/1 and 2/1). The 1/1 sensor is the first sensor to receive exhaust gases from the #1 cylinder. They provide an input voltage to the PCM. The input tells the PCM the oxygen content of the exhaust gas. The PCM uses this information to fine tune fuel delivery to main- tain the correct oxygen content at the downstream oxygen sensors. The PCM will change the air/fuel ratio until the upstream sensors input a voltage that the PCM has determined will make the downstream sensors output (oxygen content) correct.
The upstream oxygen sensors also provide an input to determine mini-catalyst efficiency. Main catalytic convertor efficiency is not calculated with this pack- age.
Downstream Sensors - California Emissions Package : Two downstream sensors are used (1/2
and 2/2). The downstream sensors are used to deter- mine the correct air-fuel ratio. As the oxygen content changes at the downstream sensor, the PCM calcu- lates how much air-fuel ratio change is required. The PCM then looks at the upstream oxygen sensor volt- age, and changes fuel delivery until the upstream sensor voltage changes enough to correct the down- stream sensor voltage (oxygen content).The downstream oxygen sensors also provide an input to determine mini-catalyst efficiency. Main cat- alytic convertor efficiency is not calculated with this package.
convertor efficiency.
Engines equipped with either a downstream sen- sor(s), or a post-catalytic sensor, will monitor cata- lytic If efficiency is below emission standards, the Malfunction Indicator Lamp (MIL) will be illuminated and a Diagnostic Trouble Code (DTC) will be set. Refer to Monitored Systems in Emission Control Systems for additional informa- tion.
REMOVAL
CAUTION: Never apply any type of grease to the oxygen sensor electrical connector, or attempt any soldering of the sensor wiring harness.
Fig.40O2SENSORSYSTEM-WITH2SENSORS 1 - POST CATALYST OXYGEN SENSOR (1/3) 2 - PRE-CATALYST OXYGEN SENSOR (1/2)
DR OXYGEN SENSOR (Continued) INSTALLATION
Threads of new oxygen sensors are factory coated with anti-seize compound to aid in removal. DO NOT add any additional anti-seize compound to threads of a new oxygen sensor.
(1) Install O2S sensor. Tighten to 30 N·m (22 ft.
lbs.) torque.
(2) Connect O2S sensor wire connector. (3) Lower vehicle.
THROTTLE BODY DESCRIPTION
The throttle body is located on the intake manifold. Fuel does not enter the intake manifold through the throttle body. Fuel is sprayed into the manifold by the fuel injectors.
OPERATION
Filtered air from the air cleaner enters the intake manifold through the throttle body. The throttle body contains an air control passage controlled by an Idle Air Control (IAC) motor. The air control passage is used to supply air for idle conditions. A throttle valve (plate) is used to supply air for above idle conditions.
5.7L V-8 Engine: The throttle body on the 5.7L engine is an electri- cally controlled unit. A mechanical cable is not used to connect the throttle body to the accelerator pedal. The Accelerator Pedal Position Sensor (APPS) along with inputs from other sensors sets the throttle blade to pre-determined positions. Except 5.7L V-8 Engine: Certain sensors are attached to the throttle body. The accelerator pedal cable, speed control cable and transmission control cable (when equipped) are con- nected to the throttle body linkage arm.
A (factory adjusted) set screw is used to mechani- cally limit the position of the throttle body throttle plate. Never attempt to adjust the engine idle speed using this screw. All idle speed functions are controlled by the PCM.
REMOVAL
3.7L V-6
A (factory adjusted) set screw is used to mechani- cally limit the position of the throttle body throttle plate. Never attempt to adjust the engine idle speed using this screw. All idle speed functions are controlled by the Powertrain Control Module (PCM).
(1) Remove air cleaner tube at throttle body. (2) Disconnect throttle body electrical connectors
at IAC motor and TPS.
FUEL INJECTION - GAS
14 - 45
(3) Remove all control cables from throttle body (lever) arm. Refer to the Accelerator Pedal and Throt- tle Cable section for removal/installation procedures. (4) Disconnect necessary vacuum lines at throttle
(5) Remove 3 throttle body mounting bolts (Fig.
body.
41).
(6) Remove throttle body from intake manifold. (7) Check condition of old throttle body-to-intake
manifold o-ring (Fig. 42).
Fig.41THROTTLEBODYMOUNTINGBOLTS-3.7L
V-6
1 - THROTTLE BODY 2 - MOUNTING BOLTS (3)
4.7L V-8
(1) Remove air duct and air resonator box at throt-
tle body.
(2) Disconnect throttle body electrical connectors
at IAC motor and TPS (Fig. 43).
(3) Remove vacuum line at throttle body. (4) Remove all control cables from throttle body (lever) arm. Refer to Accelerator Pedal and Throttle Cable.
(5) Remove three throttle body mounting bolts
(Fig. 43).
(6) Remove throttle body from intake manifold.
5.7L V-8
CAUTION: Do not use spray (carb) cleaners on any part of the throttle body. Do not apply silicone lubri- cants to any part of the throttle body.
FUEL INJECTION - GAS
14 - 46
THROTTLE BODY (Continued)DR
(5) Check condition of throttle body o-ring (Fig.
45).
(6) If the throttle body has been changed, the fol-
lowing procedure must be performed:
(a) Disconnect negative battery cable from bat- tery. Leave cable disconnected for approximately 90
seconds.(b) Reconnect cable to battery. (c) Turn ignition switch ON, but do not crank
engine.
(d) Leave ignition switch ON for a minimum of 10 seconds. This will allow PCM to learn throttle body electrical parameters.
Fig.42THROTTLEBODYO-RING-3.7LV-6
1 - INTAKE MANIFOLD 2 - THROTTLE BODY O-RING
Fig.43THROTTLEBODYMOUNTINGBOLTS-4.7L
V-8
1 - MOUNTING BOLTS (3) 2 - THROTTLE BODY 3 - IAT SENSOR CONNECTOR 4 - IAC MOTOR CONNECTOR 5 - TPS CONNECTOR
(1) Remove air duct and air resonator box at throt-
(2) Disconnect electrical connector at throttle body
(3) Remove 4 throttle body mounting bolts (Fig.
tle body.
(Fig. 44).
44).
(4) Remove throttle body from intake manifold.
Fig.445.7LV-8THROTTLEBODY
1 - THROTTLE BODY 2 - ELECTRICAL CONNECTOR 3 - SILICONE SEAL 4 - MOUNTING BOLTS (4)
5.9L V-8
A (factory adjusted) set screw is used to mechani- cally limit the position of the throttle body throttle plate. Never attempt to adjust the engine idle speed using this screw. All idle speed functions are controlled by the powertrain control module (PCM).
(1) Remove the air cleaner resonator tube. (2) Disconnect throttle body electrical connectors
at MAP sensor, IAC motor and TPS (Fig. 46).
(3) Remove vacuum line at throttle body. (4) Remove all control cables from throttle body (lever) arm. Refer to the Accelerator Pedal and Throt- tle Cable section of this group for additional informa- tion.
DR THROTTLE BODY (Continued)
FUEL INJECTION - GAS
14 - 47
Fig.455.7LV-8THROTTLEBODYO-RING
1 - INTAKE MANIFOLD 2 - THROTTLE BODY O-RING
(5) Remove four throttle body mounting bolts (Fig.
(6) Remove throttle body from intake manifold. (7) Discard old throttle body-to-intake manifold
47).
gasket.
Fig.47THROTTLEBODYMOUNTINGBOLTS-5.9L
V-8
1 - THROTTLE BODY MOUNTING BOLTS (4) 2 - THROTTLE BODY
8.0L V-10
A (factory adjusted) set screw is used to mechani- cally limit the position of the throttle body throttle plate. Never attempt to adjust the engine idle speed using this screw. All idle speed functions are controlled by the powertrain control module (PCM).
(1) Remove air plenum resonator. (2) Disconnect throttle body electrical connectors
at the IAC motor and TPS.
(3) Remove all control cables from throttle body (lever) arm. Refer to the Accelerator Pedal and Throt- tle Cable section of this group for additional informa- tion.
(4) Remove four throttle body mounting nuts (Fig.
(5) Remove throttle body from intake manifold. (6) Discard old throttle body-to-intake manifold
48).
gasket.
Fig.46SENSORELECTRICALCONNECTORS-5.9L
V-8
1 - MAP SENSOR 2 - IDLE AIR CONTROL MOTOR 3 - THROTTLE POSITION SENSOR
INSTALLATION
3.7L V-6
(1) Check condition of throttle body-to-intake man-
ifold o-ring. Replace as necessary.
(2) Clean mating surfaces of throttle body and
intake manifold.
(3) Install throttle body-to-intake manifold o-ring. (4) Install throttle body to intake manifold. (5) Install 3 mounting bolts. Tighten bolts to 12
N·m (105 in. lbs.) torque.
FUEL INJECTION - GAS
14 - 48
THROTTLE BODY (Continued)DR
(3) Install throttle body to intake manifold by posi-
tioning throttle body to manifold alignment pins.
(4) Install 4 mounting bolts. Refer to Torque Spec-
ifications.
(5) Install electrical connector. (6) Install air plenum. (7)
If the throttle body has been changed, the
following procedure must be performed:
(a) Disconnect negative battery cable from bat- tery. Leave cable disconnected for approximately 90
seconds.(b) Reconnect cable to battery. (c) Turn ignition switch ON, but do not crank
(d) Leave ignition switch ON for a minimum of 10 seconds. This will allow PCM to learn throttle body electrical parameters.
engine.
5.9L V-8
Fig.48THROTTLEBODYMOUNTINGNUTS-8.0L
V-10
1 - INTAKE MANIFOLD UPPER HALF 2 - GASKET 3 - THROTTLE BODY 4 - MOUNTING NUTS (4)(6) Install control cables. (7) Install electrical connectors. (8) Install necessary vacuum lines. (9) Install air plenum.
4.7L V-8
(1) Clean throttle body-to-intake manifold o-ring. (2) Clean mating surfaces of throttle body and
intake manifold.
(3) Install throttle body to intake manifold by posi-
tioning throttle body to manifold alignment pins.
(4) Install three mounting bolts. Tighten bolts to
12 N·m (105 in. lbs.) torque.
(5) Install control cables. (6) Install vacuum line to throttle body. (7) Install electrical connectors. (8) Install air plenum.
5.7L V-8
CAUTION: Do not use spray (carb) cleaners on any part of the throttle body. Do not apply silicone lubri- cants to any part of the throttle body.
(1) Clean and check condition of throttle body-to-
intake manifold o-ring.
intake manifold.
(2) Clean mating surfaces of throttle body and
A (factory adjusted) set screw is used to mechani- cally limit the position of the throttle body throttle plate. Never attempt to adjust the engine idle speed using this screw. All idle speed functions are controlled by the powertrain control module (PCM). (1) Clean the mating surfaces of the throttle body
and the intake manifold.
(2) Install new throttle body-to-intake manifold
gasket.
(3) Install throttle body to intake manifold. (4) Install four mounting bolts. Tighten bolts to 23
N·m (200 in. lbs.) torque.
(5) Install control cables. (6) Install vacuum line to throttle body. (7) Install electrical connectors. (8) Install air plenum.
8.0L V-10
A (factory adjusted) set screw is used to mechani- cally limit the position of the throttle body throttle plate. Never attempt to adjust the engine idle speed using this screw. All idle speed functions are controlled by the powertrain control module (PCM). (1) Clean mating surfaces of throttle body and
intake manifold.
gasket.
(2) Install new throttle body-to-intake manifold
(3) Install throttle body to intake manifold. (4) Install four mounting nuts (Fig. 48). Refer to
Torque Specifications.
(5) Install control cables. (6) Install electrical connectors. (7) Install air plenum and hoses.
DR
FUEL INJECTION - GAS
14 - 49
THROTTLE CONTROL CABLE REMOVAL
3.7L V-6
CAUTION: Be careful not to damage or kink cable core wire (within cable sheathing) while servicing accelerator pedal or throttle cable.
(1) From inside vehicle, hold up accelerator pedal. Remove plastic cable retainer (clip) and throttle cable core wire from upper end of pedal arm (Fig. 1). Plas- tic cable retainer snaps into top of pedal arm.
(2) Remove cable core wire at pedal arm. (3) From inside vehicle, remove metal clip holding
cable to dashpanel (Fig. 1).
(4) Remove air resonator box at throttle body. (5) Unsnap cable from dashpanel routing clip. (6) Remove cable housing from dash panel and
pull into engine compartment.
(7) Hold throttle in wide open position. While held in this position, slide throttle cable pin (Fig. 49) from throttle body bellcrank.
(8) Using a pick or small screwdriver, press release tab (Fig. 50) to release plastic cable mount from bracket. Press on tab only enough to release cable from bracket. If tab is pressed too much, it will be broken. Slide plastic mount (Fig. 50) towards right side of vehicle to remove throttle cable from throttle body bracket.
(9) Remove throttle cable from vehicle.
Fig.49THROTTLECABLEPIN-3.7LV-6
1 - THROTTLE CABLE PIN 2 - THROTTLE BODY BELLCRANK 3 - PUSH UP HERE
Fig.50THROTTLECABLERELEASETAB-3.7LV-6
1 - THROTTLE CABLE 2 - RELEASE TAB 3 - PICK OR SCREWDRIVER 4 - PLASTIC CABLE MOUNT4.7L V-8
CAUTION: Be careful not to damage or kink cable core wire (within cable sheathing) while servicing accelerator pedal or throttle cable.
(1) From inside vehicle, hold up accelerator pedal. Remove plastic cable retainer (clip) and throttle cable core wire from upper end of pedal arm (Fig. 1). Plas- tic cable retainer (clip) snaps into pedal arm.
(2) Remove cable core wire at pedal arm. (3) From inside vehicle, remove cable clip holding
cable to dashpanel (Fig. 1).
(4) Remove air box at throttle body. (5) Unsnap cable from dashpanel routing clip. (6) Remove cable housing from dash panel and
pull into engine compartment.
(7) Using finger pressure only, disconnect accelera- tor cable connector at throttle body bellcrank pin by pushing connector off bellcrank pin towards front of vehicle (Fig. 51). DO NOT try to pull connector off perpendicular to bellcrank pin. Connector will be broken.
(8) Lift accelerator cable from top of cable cam
(Fig. 51).
(9) Press tab (Fig. 52) to release plastic cable mount from bracket. Press on tab only enough to release cable from bracket. If tab is pressed too much, it will be broken. Slide plastic mount (Fig. 52) towards passenger side of vehicle to remove cable from bracket.
(10) Remove throttle cable from vehicle.
FUEL INJECTION - GAS
14 - 50
THROTTLE CONTROL CABLE (Continued)DR
Fig.51ACCELERATORCABLEATBELLCRANK-
4.7LV-8
1 - THROTTLE BODY 2 - SPEED CONTROL CABLE CONNECTOR 3 - OFF 4 - OFF 5 - ACCELERATOR CABLE CONNECTOR 6 - CABLE CAM 7 - BELLCRANK
5.7L V-8
The Throttle Control Cable on the 5.7L V-8 engine connects the accelerator pedal to the Accelerator Pedal Position Sensor (APPS). A separate mechanical cable is not routed to the throttle body.
CAUTION: Be careful not to damage or kink cable core wire (within cable sheathing) while servicing accelerator pedal, cables or APPS.
(1) From inside vehicle, hold up accelerator pedal. Remove plastic cable retainer and throttle cable core wire from upper end of pedal arm (Fig. 1). The plas- tic cable retainer snaps into pedal arm.
(2) Remove cable core wire at pedal arm. (3) Remove APPS. Refer to Accelerator Pedal Posi-
tion Sensor (APPS) Removal / Installation.
(4) From inside vehicle, remove cable clip (Fig. 1). (5) Remove cable housing from dash panel and
pull cable into engine compartment.
(6) Remove cable housing at APPS bracket by pressing on release tab with a small screwdriver. To prevent cable housing breakage, press on tab only enough to release cable from APPS bracket.
Fig.52ACCELERATORCABLERELEASETAB-
4.7LV-8
1 - ACCELERATOR CABLE 2 - PLASTIC CABLE MOUNT 3 - PRESS TAB FOR REMOVAL 4 - CABLE BRACKET 5 - SLIDE FOR REMOVAL
5.9L V-8
CAUTION: Be careful not to damage or kink cable core wire (within cable sheathing) while servicing accelerator pedal or cables.
(1) From inside vehicle, hold up accelerator pedal. Remove plastic cable retainer and throttle cable core wire from upper end of pedal arm (Fig. 1). The plas- tic cable retainer snaps into pedal arm.
(2) Remove cable core wire at pedal arm. (3) Remove air resonator at throttle body. (4) From inside vehicle, remove cable clip (Fig. 1). (5) Remove cable housing from dash panel and
pull cable into engine compartment.
(6) Disconnect cable from routing/holddown clip. (7) Slip cable end rearward from pin on throttle
body (Fig. 53).
(8) Remove cable housing at throttle body mount- ing bracket by pressing on release tab with a small screwdriver (Fig. 54). To prevent cable housing breakage, press on tab only enough to release cable from bracket. Lift cable housing straight up from bracket while pressing on release tab. Remove throttle cable from vehicle.
DR THROTTLE CONTROL CABLE (Continued)
FUEL INJECTION - GAS
14 - 51
(3) Remove necessary air intake tubes and resona-
tor housing.
(4) From inside vehicle, pinch both sides of plastic
cable housing retainer tabs at dash panel (Fig. 1).
(5) Remove cable housing from dash panel and
pull cable into engine compartment.
(6) Remove throttle cable socket at throttle lever
ball (Fig. 55) (snaps off).
Fig.53THROTTLECABLEATTHROTTLEBODY-
5.9L
1 - THROTTLE LEVER PIN 2 - CAM (V-8 ENGINE ONLY) 3 - THROTTLE CABLE END
Fig.54CABLERELEASE-5.9LV-8
1 - TAB
8.0L V-10
CAUTION: Be careful not to damage or kink cable core wire (within cable sheathing) while servicing accelerator pedal or cables.
(1) From inside vehicle, hold up accelerator pedal. Remove plastic cable retainer and throttle cable core wire from upper end of pedal arm (Fig. 1). The plas- tic cable retainer snaps into pedal arm.
(2) Remove cable core wire at pedal arm.
Fig.55THROTTLECABLEATTHROTTLEBODY-
8.0LV-10
1 - PRESS TAB FOR CABLE REMOVAL 2 - THROTTLE CABLE 3 - CABLE SOCKET 4 - LEVER BALL 5 - MOUNTING BRACKET(7) Remove cable housing at throttle body mount- ing bracket by pressing on release tab with a small screwdriver (Fig. 55). To prevent cable housing breakage, press on tab only enough to release cable from bracket. Lift cable housing straight up from bracket while pressing on release tab. Remove throttle cable from vehicle.
INSTALLATION
3.7L V-6
(1) Slide accelerator cable plastic mount into throt- tle body mounting bracket. Continue sliding until release tab (Fig. 50) is aligned to hole in mounting bracket.
(2) Hold throttle in wide open position. While held in this position, slide throttle cable pin (Fig. 49) into throttle body bellcrank.
(3) Push cable housing into rubber grommet and
through opening in dash panel.
FUEL INJECTION - GAS
14 - 52
THROTTLE CONTROL CABLE (Continued)DR
(4) From inside vehicle, install metal clip holding
cable to dashpanel (Fig. 1).
(5) From inside vehicle, slide throttle cable core
wire into opening (slot) in top of pedal arm.
(2) Hold throttle in wide open position. While held in this position, slide throttle cable pin into throttle body bellcrank.
(3) Push cable housing into rubber grommet and
(6) Push plastic cable retainer (clip) into pedal arm
through opening in dash panel.
(5) Install rubber grommet into dash panel until
bracket (push down and lock)
opening until it snaps in place.
(7) Install air resonator tube to throttle body. (8) Before starting engine, operate accelerator
pedal to check for any binding.
4.7L V-8
(1) Slide accelerator
cable plastic mount
bracket. Continue sliding until aligned to hole in mounting bracket.
tab (Fig. 52)
into is
(2) Route accelerator cable over top of cable cam. (3) Connect cable end to throttle body bellcrank
pin (snaps on rearward).
(4) Slide rubber grommet away from plastic cable
housing.
seated.
(6) Push cable housing into rubber grommet and
through opening in dash panel.
(7) From inside vehicle, install clip holding cable
to dashpanel (Fig. 1).
(8) From inside vehicle, slide throttle cable core
wire into opening in top of pedal arm.
(9) Push cable retainer (clip) into pedal arm open-
ing until it snaps in place.
(10) Snap cable into dashpanel routing clip. (11) Install air resonator tube to throttle body. (12) Before starting engine, operate accelerator
pedal to check for any binding.
5.7L V-8
(1) Attach cable to Accelerator Pedal Position Sen-
sor (APPS). Refer to APPS Removal / Installation.
(2) Push cable housing into rubber grommet and
through opening in dash panel.
(3) From inside vehicle, install clip holding cable
to dashpanel (Fig. 1).
(4) From inside vehicle, slide throttle cable core
wire into opening in top of pedal arm.
(5) Push cable retainer (clip) into pedal arm open-
ing until it snaps in place.
(6) Before starting engine, operate accelerator
pedal to check for any binding.
(7) If necessary, use DRB IIIt Scan Tool to erase from
any APPS Diagnostic Trouble Codes (DTC’s) PCM.
5.9L V-8
(1) Slide accelerator cable plastic mount into throt- tle body mounting bracket. Continue sliding until release tab (Fig. 54) is aligned to hole in mounting bracket.
(4) From inside vehicle, install metal clip holding
cable to dashpanel (Fig. 1).
(5) From inside vehicle, slide throttle cable core
wire into opening (slot) in top of pedal arm.
(6) Push plastic cable retainer (clip) into pedal arm
opening until it snaps in place.
(7) Install air resonator tube to throttle body. (8) Before starting engine, operate accelerator
pedal to check for any binding.
8.0L V-10
(1) Connect cable end socket to throttle body lever
ball (snaps on) (Fig. 55). to
(2) Connect
cable
throttle body mounting
(3) Install the remaining cable housing end into and through the dash panel opening (snaps into posi- tion). The two plastic pinch tabs (Fig. 1) should lock the cable to dash panel.
(4) From inside the vehicle, hold up the accelera- tor pedal. Install the throttle cable core wire and plastic cable retainer into and through the upper end of the pedal arm (the plastic retainer is snapped into the pedal arm). When installing the plastic retainer to the accelerator pedal arm, note the index tab on the pedal arm (Fig. 1). Align the index slot on the plastic cable retainer to this index tab.
(5) Install air resonator tube to throttle body. (6) Before starting engine, operate accelerator
pedal to check for any binding.
THROTTLE POSITION SENSOR DESCRIPTION
The 3-wire Throttle Position Sensor
is mounted on the throttle body and is connected to the throttle blade shaft.
(TPS)
The 5.7L V-8 engine does not use a separate TPS
on the throttle body.
OPERATION
The 5.7L V-8 engine does not use a separate Throt-
tle Position Sensor (TPS) on the throttle body.
The 3–wire TPS provides the Powertrain Control Module (PCM) with an input signal (voltage) that represents the throttle blade position of the throttle body. The sensor is connected to the throttle blade shaft. As the position of the throttle blade changes, the output voltage of the TPS changes.
DR THROTTLE POSITION SENSOR (Continued)
FUEL INJECTION - GAS
14 - 53
The PCM supplies approximately 5 volts to the TPS. The TPS output voltage (input signal to the PCM) represents the throttle blade position. The PCM receives an input signal voltage from the TPS. This will vary in an approximate range of from .26
volts at minimum throttle opening (idle), to 4.49 volts at wide open throttle. Along with inputs from other sensors, the PCM uses the TPS input to determine current engine operating conditions. In response to engine operating conditions, the PCM will adjust fuel injector pulse width and ignition timing.The PCM needs to identify the actions and position of the throttle blade at all times. This information is needed to assist in performing the following calcula- tions:† Ignition timing advance † Fuel injection pulse-width † Idle (learned value or minimum TPS) † Off-idle (0.06 volt) † Wide Open Throttle (WOT) open loop (2.608
volts above learned idle voltage) † Deceleration fuel lean out † Fuel cutoff during cranking at WOT (2.608 volts † A/C WOT cutoff(certain automatic transmis-
above learned idle voltage)
sions only)
REMOVAL
3.7L V6
The Throttle Position Sensor (TPS) is mounted to
the throttle body (Fig. 56), or (Fig. 57).
(1) Remove air resonator tube at throttle body. (2) Disconnect TPS electrical connector. (3) Remove 2 TPS mounting screws. (4) Remove TPS.
4.7L V-8
The TPS is located on the throttle body (Fig. 58). (1) Remove air duct and tube at throttle body. (2) Disconnect TPS electrical connector. (3) Remove two TPS mounting bolts (screws) (Fig.
58).
(4) Remove TPS from throttle body.
5.7L V-8
The 5.7L V-8 engine does not use a separate Throt-
tle Position Sensor (TPS) on the throttle body.
5.9L V-8
The TPS is located on the side of the throttle body
(Fig. 59).
(1) Remove air intake tube at throttle body. (2) Disconnect TPS electrical connector. (3) Remove two TPS mounting bolts (Fig. 59). (4) Remove TPS from throttle body.
Fig.56TPSLOCATION-3.7LV-6
1 - THROTTLE POSITION SENSOR (TPS) 2 - MOUNTING SCREWS 3 - IDLE AIR CONTROL MOTOR (IAC) 4 - MOUNTING SCREWS
Fig.57TPSINSTALLATION-3.7V-6
1 - THROTTLE BODY 2 - TPS 3 - THROTTLE BODY SHAFT 4 - SOCKET LOCATING TANGS
8.0L V-10
The TPS is located on the side of the throttle body
(Fig. 60).
(1) Remove air plenum. (2) Disconnect TPS electrical connector.
FUEL INJECTION - GAS
14 - 54
THROTTLE POSITION SENSOR (Continued)DR
Fig.58TPSLOCATION-4.7L
1 - THROTTLE BODY 2 - TPS 3 - IAC MOTOR 4 - IAT SENSOR 5 - MOUNTING SCREWS
Fig.59TPSLOCATION-5.9LV-8
1 - THROTTLE POSITION SENSOR 2 - MOUNTING SCREWS
(3) Remove two TPS mounting bolts (Fig. 60). (4) Remove TPS from throttle body.
Fig.60TPSMOUNTINGBOLTS-8.0LV-10
1 - MOUNTING BOLTS (2) 2 - IDLE AIR CONTROL MOTOR 3 - THROTTLE POSITION SENSOR 4 - THROTTLE BODY
INSTALLATION
3.7L V-6
The Throttle Position Sensor (TPS) is mounted to
the throttle body (Fig. 56).
The throttle shaft end of throttle body slides into a socket in TPS (Fig. 61). The TPS must be installed so that it can be rotated a few degrees. (If sensor will not rotate, install sensor with throttle shaft on other side of socket tangs). The TPS will be under slight tension when rotated.
(1) Install TPS and retaining screws. (2) Tighten screws to 7 N·m (60 in. lbs.) torque. (3) Connect TPS electrical connector to TPS. (4) Manually operate throttle (by hand) to check
for any TPS binding before starting engine.
(5) Install air cleaner tube to throttle body.
4.7L V-8
The throttle shaft end of throttle body slides into a socket in TPS (Fig. 62). The TPS must be installed so that it can be rotated a few degrees. If sensor will not rotate, install sensor with throttle shaft on other side of socket tangs. The TPS will be under slight tension when rotated.
(1) Install TPS and two retaining bolts. (2) Tighten bolts to 7 N·m (60 in. lbs.) torque. (3) Manually operate throttle control lever by hand
to check for any binding of TPS.
(4) Connect TPS electrical connector to TPS.
DR THROTTLE POSITION SENSOR (Continued)
FUEL INJECTION - GAS
14 - 55
5.9L V-8
The throttle shaft end of the throttle body slides into a socket in the TPS (Fig. 63). The TPS must be installed so that it can be rotated a few degrees. If sensor will not rotate, install sensor with throttle shaft on other side of socket tangs. The TPS will be under slight tension when rotated.
(1) Install TPS and two retaining bolts. (2) Tighten bolts to 7 N·m (60 in. lbs.) torque. (3) Manually operate throttle control lever by hand
to check for any binding of TPS.
(4) Connect TPS electrical connector to TPS. (5) Install air intake tube.
Fig.61TPSINSTALLATION-3.7L
1 - THROTTLE BODY 2 - TPS 3 - THROTTLE BODY SHAFT 4 - SOCKET LOCATING TANGS
(5) Install air duct/air box to throttle body.
Fig.63TPSINSTALLATION-5.9LV-8AND8.0LV-10
1 - THROTTLE BODY 2 - THROTTLE POSITION SENSOR 3 - THROTTLE SHAFT 4 - SOCKET LOCATING TANGS8.0L V-10
The throttle shaft end of the throttle body slides into a socket in the TPS (Fig. 63). The TPS must be installed so that it can be rotated a few degrees. If sensor will not rotate, install sensor with throttle shaft on other side of socket tangs. The TPS will be under slight tension when rotated.
(1) Install TPS and two retaining bolts. Refer to
Torque Specifications.
(2) Manually operate throttle control lever by hand
to check for any binding of TPS.
(3) Connect TPS electrical connector to TPS. (4) Install air plenum.
Fig.62TPSINSTALLATION-4.7L
1 - THROTTLE BODY 2 - LOCATING TANGS 3 - THROTTLE POSITION SENSOR 4 - SOCKET 5 - THROTTLE SHAFT
14 - 56
FUEL DELIVERY - DIESEL
FUEL DELIVERY - DIESEL
TABLE OF CONTENTS
page
DR
page
FUEL DELIVERY - DIESEL
FUEL LINES
DESCRIPTION - DIESEL FUEL SYSTEM . . . . . 57
STANDARD PROCEDURESTANDARD PROCEDURES - WATER
DRAINING AT FUEL FILTER . . . . . . . . . . . . . . 57
STANDARD PROCEDURES - CLEANING
FUEL SYSTEM PARTS . . . . . . . . . . . . . . . . . 58
STANDARD PROCEDURE - FUEL SYSTEM
PRIMING . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
SPECIFICATIONS
FUEL SYSTEM PRESSURE - DIESEL FUEL INJECTOR FIRING ORDER - DIESEL
. . . . . . 60
. 60SPECIAL TOOLS
DIESEL FUEL SYSTEM . . . . . . . . . . . . . . . . . 60
FUEL FILTER / WATER SEPARATOR
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . 61
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . 62FUEL HEATER
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . 63
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
DIAGNOSIS AND TESTING - FUEL HEATER . . . 63
REMOVALREMOVAL/INSTALLATION . . . . . . . . . . . . . . . 64
FUEL HEATER RELAY
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . 64
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . 64FUEL INJECTION PUMP
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . 64
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
DIAGNOSIS AND TESTING - FUEL INJECTIONPUMP TIMING . . . . . . . . . . . . . . . . . . . . . . . . 65
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . 67FUEL LEVEL SENDING UNIT / SENSOR
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . 68
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
REMOVALREMOVAL/INSTALLATION . . . . . . . . . . . . . . . 68
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . 69
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
DIAGNOSIS AND TESTING - HIGH-PRESSURE FUEL LINE LEAKS . . . . . . . . . . . 69
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . 71FUEL PRESSURE SENSOR
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . 72
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . 72FUEL PRESSURE LIMITING VALVE
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . 72
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . 73FUEL TANK
DESCRIPTION - DIESEL . . . . . . . . . . . . . . . . . . 73
. . . . . . . . . . . . . . . . . . . . . 73
REMOVAL - DIESEL INSTALLATION - DIESEL . . . . . . . . . . . . . . . . . 74FUEL TANK MODULE
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . 75
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . 75FUEL TRANSFER PUMP
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . 75
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . 76CASCADE OVERFLOW VALVE
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . 77
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
REMOVALREMOVAL/INSTALLATION . . . . . . . . . . . . . . . 77
WATER IN FUEL SENSOR
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . 77
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78FUEL DRAIN CIRCUIT
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
DR
FUEL DELIVERY - DIESEL
14 - 57
FUEL DELIVERY - DIESEL DESCRIPTION - DIESEL FUEL SYSTEM
The fuel system used on the Cummins engine is an electronically controlled, Bosch HPCR (High-Pressure Common Rail) system. The HPCR system consists of five main components: † Electric Fuel Transfer (lift) Pump † Fuel Pump/Gear Pump (attached to fuel injec- tion pump) † High-Pressure Fuel Injection Pump † Fuel Injection Rail † Fuel Injectors Also to be considered as part of the overall fuel system are: † Accelerator Pedal † Air Cleaner Housing/Element † Fuel Drain Manifold (passage) † Fuel Drain Valve (at filter) † Fuel Filter/Water Separator † Fuel Heater † Fuel Heater Relay † Fuel Level (gauge) Sending Unit † Fuel Tank † Fuel Tank Module (containing fuel gauge send- ing unit and separate fuel filter located at bottom of tank module)
† Fuel Tank Filler/Vent Tube Assembly † Fuel Tank Filler Tube Cap † Fuel Tubes/Lines/Hoses † High-Pressure Fuel Injector Lines † In-Tank Fuel Filter (at bottom of fuel tank mod- ule)† Low-Pressure Fuel Supply Lines † Low-Pressure Fuel Return Line † Overflow Valve † Quick-Connect Fuel Line Fittings † Throttle Cable † Water Draining (maintenance) † Water-In-Fuel (WIF) Sensor The fuel injection pump supplies high pressure to the fuel rail independent of engine speed. This high pressure is then accumulated in the fuel rail. High pressure fuel is constantly supplied to the injectors by the fuel rail. The Engine Control Module (ECM) controls the fueling and timing of the engine by actu- ating the injectors.
Fuel enters the system from the electric fuel trans- fer (lift) pump, which is attached to the fuel filter assembly. Fuel is forced through the fuel filter ele- ment and then enters the Fuel Pump/Gear Pump, which is attached to the rear of the fuel injection pump. The Fuel Pump/Gear Pump is a low-pressure pump and produce pressures ranging from 551.5 kpa (80 psi) to 1241 kpa (180) psi. Fuel then enters the fuel injection pump. Low pressure fuel is then sup- plied to the FCA (Fuel Control Actuator).
The FCA is an electronically controlled solenoid valve. The ECM controls the amount of fuel that enters the high-pressure pumping chambers by open- ing and closing the FCA based on a demanded fuel pressure. The FPS (Fuel Pressure Sensor) on the fuel rail provides the actual fuel pressure. When the actuator is opened, the maximum amount of fuel is being supplied to the fuel injection pump. Any fuel that does not enter the injection pump is directed to the overflow valve. The overflow valve regulates how much excess fuel is used for lubrication of the pump and how much is returned to the tank through the drain manifold.
Fuel entering the injection pump is pressurized to between 300 - 1600 bar by three radial pumping chambers. The pressurized fuel is then supplied to the fuel rail.
Some fuel system components are shown in.
WARNING: HIGH-PRESSURE FUEL LINES DELIVER DIESEL FUEL UNDER EXTREME PRESSURE FROM THE INJECTION PUMP TO THE FUEL INJECTORS. THIS MAY BE AS HIGH AS 160,000 KPA (23,206
PSI). USE EXTREME CAUTION WHEN INSPECTING FOR HIGH-PRESSURE FUEL LEAKS. INSPECT FOR HIGH-PRESSURE FUEL LEAKS WITH A SHEET OF CARDBOARD. HIGH FUEL INJECTION PRESSURE CAN CAUSE PERSONAL INJURY IF CONTACT IS MADE WITH THE SKIN.Certain fuel system components can be found in
(Fig. 1), or (Fig. 2).
STANDARD PROCEDURE
STANDARD PROCEDURES - WATER DRAINING AT FUEL FILTER
Refer to Fuel Filter/Water Separator removal/in-
stallation for procedures.
FUEL DELIVERY - DIESEL
14 - 58
FUEL DELIVERY - DIESEL (Continued)DR
Fig.1DIESELFUELSYSTEMCOMPONENTS
1 - ENGINE COOLANT TEMPERATURE (ECT) SENSOR 2 - THROTTLE LEVER BELLCRANK AND APPS (ACCELERATOR PEDAL POSITION SENSOR) 3 - INTAKE MANIFOLD AIR HEATER/ELEMENTS 4 - FUEL PRESSURE SENSOR 5 - FUEL LIMITING VALVE 6 - HIGH-PRESSURE FUEL LINES 7 - FUEL HEATER 8 - HIGH-PRESSURE FUEL INJECTOR RAIL 9 - FUEL HEATER TEMPERATURE SENSOR (THERMOSTAT) 10 - FUEL FILTER/WATER SEPARATOR 11 - FUEL TRANSFER (LIFT) PUMP 12 - FUEL DRAIN MANIFOLD 13 - DRAIN VALVE
STANDARD PROCEDURES - CLEANING FUEL SYSTEM PARTS
CAUTION: Cleanliness cannot be overemphasized when handling or replacing diesel fuel system com- ponents. This especially includes the fuel injectors, high-pressure fuel injection pump. Very tight tolerances are used with these parts. Dirt contamination could cause rapid part wear and pos- sible plugging of fuel injector nozzle tip holes. This in turn could lead to possible engine misfire.
lines and fuel
14 - FUEL SUPPLY LINE (LOW-PRESSURE, TO ENGINE) 15 - FUEL RETURN LINE CONNECTION (TO FUEL TANK)
16 - FUEL DRAIN TUBE 17 - OIL PRESSURE SENSOR 18 - ENGINE CONTROL MODULE (ECM) 19 - FUEL INJECTION PUMP 20 - CRANKSHAFT POSITION (ENGINE SPEED) SENSOR 21 - CAMSHAFT POSITION SENSOR (CMP) 22 - FUEL CONTROL ACTUATOR (FCA) 23 - CASCADE OVERFLOW VALVE
Always wash/clean any fuel system component thoroughly before disassembly and then air dry. Cap or cover any open part after disassembly. Before assembly, examine each part for dirt, grease or other contaminants and clean if necessary. When installing new parts, lubricate them with clean engine oil or clean diesel fuel only.
DR FUEL DELIVERY - DIESEL (Continued)
FUEL DELIVERY - DIESEL
14 - 59
25 seconds after the starter is quickly engaged, and then disengaged without allowing the engine to start. The pump shuts off immediately if the key is on and the engine stops running.
(1) Turn key to CRANK position and quickly release key to ON position before engine starts. This will operate fuel transfer pump for approximately 25
seconds.(2) If the engine does not start after 25 seconds, turn key OFF. Repeat previous step until engine starts.
(3) Fuel system priming is now completed. (4) Attempt to start engine. If engine will not start, proceed to following steps. When engine does start, it may run erratically and be noisy for a few minutes. This is a normal condition.
CAUTION: Do not engage the starter motor for more than 30 seconds at a time. Allow two minutes between cranking intervals.
Fig.2FUELINJECTORS
1 - SOLENOID CONNECTIONS 2 - ROCKER HOUSING 3 - FUEL INJECTOR 4 - PASSTHROUGH CONNECTOR
STANDARD PROCEDURE - FUEL SYSTEM PRIMING
A certain amount of air becomes trapped in the fuel system when fuel system components on the supply and/or high-pressure side are serviced or replaced. Fuel system priming is accomplished using the electric fuel transfer (lift) pump.
Servicing or replacing fuel system components usu-
ally will not require fuel system priming.
The fuel transfer (lift) pump is self-priming: When the key is first turned on (without cranking engine), the pump operates for approximately 2 seconds and then shuts off. The pump will also operate for up to
(5) Perform previous fuel priming procedure steps using fuel transfer pump. Be sure fuel is present at fuel tank.
(6) Crank the engine for 30 seconds at a time to
allow fuel system to prime.
WARNING: THE FUEL INJECTION PUMP SUPPLIES EXTREMELY HIGH FUEL PRESSURE TO EACH INDI- VIDUAL INJECTOR THROUGH THE HIGH-PRES- SURE LINES. FUEL UNDER THIS AMOUNT OF PRESSURE CAN PENETRATE THE SKIN AND CAUSE PERSONAL INJURY. WEAR SAFETY GOG- GLES AND ADEQUATE PROTECTIVE CLOTHING. DO NOT LOOSEN FUEL FITTINGS WHILE ENGINE IS RUNNING.
WARNING: ENGINE MAY START WHILE CRANKING STARTER MOTOR.
FUEL DELIVERY - DIESEL
14 - 60
FUEL DELIVERY - DIESEL (Continued) SPECIFICATIONSFUEL SYSTEM PRESSURE - DIESEL
DR
DESCRIPTION
Fuel Transfer (Lift) Pump Pressure
PRESSURE
Minimum 9.5 psi
FUEL INJECTOR FIRING ORDER - DIESEL
1–5–3–6–2–4
SPECIAL TOOLS
DIESEL FUEL SYSTEM
FUELPRESSURETESTADAPTER-#9012
FUELPRESSURETESTADAPTER-#9014
FUELINJECTORREMOVER-#9010
PRESSURECAP-#9011
FUELPRESSURETESTADAPTER-#9013
DR FUEL DELIVERY - DIESEL (Continued)
FUEL DELIVERY - DIESEL
14 - 61
A Water-In-Fuel (WIF) sensor is attached to side of canister. Refer to Water-In-Fuel Sensor Description/ Operation.
The fuel heater is installed into the top of the fil- ter/separator housing. Refer to Fuel Heater Descrip- tion/Operation.
REMOVAL
FUELINJECTORTUBE(CONNECTOR)REMOVER-
#9015
SPANNERWRENCH(FUELTANKMODULE
REMOVAL/INSTALLATION)-#6856
ENGINEROTATING(BARRING)TOOL-#7471B
(ALSOPARTOFKIT#6860)
FUEL FILTER / WATER SEPARATOR DESCRIPTION
The fuel filter/water separator assembly is located on left side of engine above starter motor. The assem- bly also includes the fuel heater and Water-In-Fuel (WIF) sensor, and fuel transfer pump.
OPERATION
The fuel
filter/water separator protects the fuel injection pump by removing water and contaminants from the fuel. The construction of the filter/separator allows fuel to pass through it, but helps prevent moisture (water) from doing so. Moisture collects at the bottom of the canister.
Refer to the maintenance schedules for the recom-
mended fuel filter replacement intervals.
For draining of water from canister, refer to Fuel Filter/Water Separator Removal/Installation section.
Refer to maintenance schedules in this manual for
recommended fuel filter replacement intervals.
Draining water from fuel filter/water separa-
tor housing:
The housing drain valve (Fig. 3) or (Fig. 4) serves two purposes. One is to partially drain filter hous- ing of excess water. The other is to completely drain housing for fuel filter, drain valve, heater element, , water-in-fuel sensor replacement or transfer pump replacement.
The filter housing should be partially drained whenever water-in-fuel warning lamp remains illumi- nated. lamp will be illuminated for approximately two seconds when ignition key is ini- tially placed in ON position for a bulb check).
(Note that
(1) A drain hose (Fig. 3) or (Fig. 4) is located at bottom of drain valve. Place drain pan under drain. (2) With engine not running, rotate drain valve handle rearward to OPEN (DRAIN) position. Hold drain valve open until all water and contaminants have been removed and clean fuel exits.
(3) If drain valve, fuel heater element or Water-In- Fuel (WIF) sensor is being replaced, drain housing completely. Dispose of mixture in drain pan according to applicable regulations.
(4) After draining operation, push valve handle
forward to CLOSE position.
(5) Fuel Filter Replacement: The fuel filter is
located inside of the fuel filter housing.
(a) Clean all debris from around canister. (b) Remove filter lid (Fig. 5) using a socket. Attach socket to large hex on top of lid (Fig. 5). Rotate removal. Remove o-ring.
counter-clockwise
for
(c) Remove filter element by twisting element
sideways from filter lid. (6) Water-In-Fuel (WIF) Sensor Replacement: The WIF sensor is located on the side of the fuel fil- ter housing (Fig. 3) or (Fig. 4).
(a) Disconnect electrical connector at sensor. (b) Clean area around sensor. (c) Remove sensor by rotating counter-clockwise. (d) Check condition of sensor o-ring. Replace if
damaged. (7) Fuel Heater Element Replacement: The heater element is located in the fuel filter housing (Fig. 3) or (Fig. 4).
(a) Remove fuel filter. See previous steps.
FUEL DELIVERY - DIESEL
14 - 62
FUEL FILTER / WATER SEPARATOR (Continued)DR
(b) Disconnect electrical connector. (c) Remove two T-15 Torx head mounting screws
from fuel heater element.
(d) Remove fuel filter cover and filter element. (e) Remove fuel heater.
(8) Drain Valve Replacement: The drain valve assembly is located on the side of the fuel filter hous- ing (Fig. 3) or (Fig. 4).
(a) Disconnect drain hose from the fuel drain
valve.
Torx head).
(b) Remove 4 drain valve mounting screws (T-15
(c) Remove drain valve from filter housing.
Fig.4FILTERHOUSING(LATE)
1 - FILTER HOUSING 2 - FUEL HEATER AND THERMOSTAT 3 - FUEL HEATER MOUNTING SCREWS 4 - FUEL HEATER ELEC. CONNECTOR 5 - WIF SENSOR 6 - WIF SENSOR ELEC. CONNECTOR 7 - DRAIN HOSE 8 - DRAIN VALVE MOUNTING SCREWS 9 - DRAIN VALVE
Fig.5FILTERCOVER(LID)
1 - FILTER COVER 2 - ATTACH SOCKET HERE
Fig.3FILTERHOUSING(EARLY)
1 - FILTER HOUSING 2 - FUEL HEATER AND THERMOSTAT 3 - FUEL HEATER MOUNTING SCREWS 4 - FUEL HEATER ELEC. CONNECTOR 5 - DRAIN VALVE 6 - DRAIN VALVE MOUNTING SCREWS 7 - DRAIN HOSE 8 - WIF SENSOR 9 - WIF SENSOR ELEC. CONNECTOR
INSTALLATION
Refer to maintenance schedules for recommended
fuel filter replacement intervals.
(1) Thoroughly clean inside of filter housing, filter
cap and all related components.
(2) Fuel Filter:
(a) The engine has a self-priming low-pres- sure fuel system. Refer to Standard Proce- dures-Fuel System Priming.
(b) Install new o-ring to canister lid and lubri-
cate o-ring with 30W oil.
DR FUEL FILTER / WATER SEPARATOR (Continued)
FUEL DELIVERY - DIESEL
14 - 63
(c) Position new element to canister lid. Place
this assembly into canister by rotating clockwise.
(d) Tighten cap to 34 N·m (25 ft. lbs.) torque. Do
not overtighten cap. (3) Water-In-Fuel (WIF) Sensor:
(a) Install new o-ring seal to WIF sensor. (b) Apply a light film of clean diesel oil to o-ring
seal.
(c) Install sensor into housing. (d) Tighten sensor to 4.5 N·m (39 in. lbs.) torque. (e) Connect electrical connector to WIF sensor.
(4) Fuel Heater Element:
(a) Install fuel heater into fuel filter housing. (b) Install fuel heater thermostat into fuel filter
housing.
thermostat.
(c) Install
fuel heater mounting screws and
tighten to 1-1.5 N·m torque.
(d) Connect electrical connector to fuel heater
(e) Install new filter cover O-ring onto fuel filter
housing cover and lubricate with 30W oil.
(f) Tighten fuel filter housing cover (lid) to 34
N·m (25 ft. lbs.). (5) Drain Valve:
ing.
(a) Install 2 new o-rings to valve and filter hous-
(b) Lubricate with silicon grease. (c) Install fuel drain valve. (d) Install 4 mounting screws and tighten to
1–1.5 N·m (8–13 in. lbs.) torque.
(e) Connect drain hose to drain valve.
(6) Start engine and check for leaks.
FUEL HEATER DESCRIPTION
The fuel heater assembly is located on the side of
the fuel filter housing (Fig. 3) or (Fig. 4).
The heater/element assembly is equipped with a temperature sensor (thermostat) that senses fuel temperature. This sensor is attached to the fuel heat- er/element assembly.
OPERATION
The fuel heater is used to prevent diesel fuel from
waxing during cold weather operation.
When the temperature is below 45 ±8 degrees F, the temperature sensor allows current to flow to the heater element warming the fuel. When the temper- ature is above 75 ±8 degrees F, the sensor stops cur- rent flow to the heater element.
Battery voltage to operate the fuel heater element is supplied from the ignition switch and through the fuel heater relay. Also refer to Fuel Heater Relay.
The fuel heater element and fuel heater relay are not computer controlled.
The heater element operates on 12 volts, 300 watts
at 0 degrees F.
DIAGNOSIS AND TESTING - FUEL HEATER
The fuel heater is used to prevent diesel fuel from
waxing during cold weather operation.
NOTE: The fuel heater element, fuel heater relay and fuel heater temperature sensor are not con- trolled by the Engine Control Module (ECM), or the Powertrain Control Module (PCM).
A malfunctioning fuel heater can cause a wax build-up in the fuel filter/water separator. Wax build-up in the filter/separator can cause engine starting problems and prevent the engine from rev- ving up. It can also cause blue or white fog-like exhaust. If the heater is not operating in cold tem- peratures, the engine may not operate due to fuel waxing.
The fuel heater assembly is located on the side of
fuel filter housing.
The heater assembly is equipped with a built-in fuel temperature sensor (thermostat) that senses fuel temperature. When fuel temperature drops below 45
degrees ± 8 degrees F, the sensor allows current to flow to built-in heater element to warm fuel. When fuel temperature rises above 75 degrees ± 8 degrees F, the sensor stops current flow to heater element (circuit is open).Voltage to operate fuel heater element is supplied from ignition switch, through fuel heater relay (also refer to Fuel Heater Relay), to fuel temperature sen- sor and on to fuel heater element.
The heater element operates on 12 volts, 300 watts at 0 degrees F. As temperature increases, power requirements decrease.
A minimum of 7 volts is required to operate fuel heater. The resistance value of heater element is less than 1 ohm (cold) and up to 1000 ohms warm.
TESTING
(Fig. 3) or (Fig. 4).
(1) Disconnect electrical connector from thermostat
Ambient temperature must be below circuit close temperature, If necessary, induce this ambient tem- perature by placing ice packs on thermostat to pro- duce an effective ambient temperature below circuit close temperature. For first check of thermostat you can hear click of thermostat when circuit closes.
Measure resistance across two pins. Operating
range is 0.3 — 0.45 Ohms.
(2) If resistance is out of range, remove thermostat and check resistance across terminal connections of
FUEL DELIVERY - DIESEL
14 - 64
FUEL HEATER (Continued)heater. The heater can be check at room tempera- ture. Operating range is 0.3 — 0.45 Ohms.
(3) Replace heater if resistance is not within oper-
ating range.
heater thermostat.
(4) If heater is within operating range, replace
REMOVAL
REMOVAL/INSTALLATION
The fuel heater/element/sensor assembly is located inside of the fuel filter housing. Refer to Fuel Filter/ Water Separator Removal/Installation for procedures.
FUEL HEATER RELAY DESCRIPTION
The fuel heater relay is located in Power Distribu- tion Center (PDC) (Fig. 6). Refer to label on inside of PDC cover for relay location.
Fig.6POWERDISTRIBUTIONCENTERLOCATION 1 - CLIP 2 - BATTERY 3 - TRAY 4 - NEGATIVE CABLE 5 - POSITIVE CABLE 6 - CLIP 7 - FENDER INNER SHIELD 8 - POWER DISTRIBUTION CENTER
OPERATION
Battery voltage to operate the fuel heater element is supplied from the ignition switch through the fuel heater relay. The fuel heater element and fuel heater relay are not computer controlled.
REMOVAL
The fuel heater relay is located in the Power Dis- tribution Center (PDC) (Fig. 7). Refer to label under PDC cover for relay location.
(1) Remove PDC cover. (2) Remove relay from PDC.
DR
(3) Check condition of relay terminals and PDC connector terminals for damage or corrosion. Repair if necessary before installing relay.
(4) Check for pin height (pin height should be the same for all terminals within the PDC connector). Repair if necessary before installing relay.
Fig.7POWERDISTRIBUTIONCENTERLOCATION 1 - CLIP 2 - BATTERY 3 - TRAY 4 - NEGATIVE CABLE 5 - POSITIVE CABLE 6 - CLIP 7 - FENDER INNER SHIELD 8 - POWER DISTRIBUTION CENTER
INSTALLATION
The fuel heater relay is located in the Power Dis- tribution Center (PDC) (Fig. 7). Refer to label under PDC cover for relay location.
(1) Install relay to PDC. (2) Install cover to PDC.
FUEL INJECTION PUMP DESCRIPTION
A Robert Bosch high-pressure fuel injection pump is used. The pump is attached to the back of the tim- ing gear cover at the left / rear side of the engine.
OPERATION
The fuel injection pump supplies high pressure to the fuel rail independent of engine speed. This high pressure is then accumulated in the fuel rail. High pressure fuel is constantly supplied to the injectors by the fuel rail. The Engine Control Module (ECM) controls the fueling and timing of the engine by actu- ating the injectors.
Fuel enters the system from the electric fuel trans- fer (lift) pump, which is attached to the fuel filter assembly. Fuel is forced through the fuel filter ele- ment and then enters the Fuel Pump/Gear Pump, which is attached to the rear of the fuel injection
DR FUEL INJECTION PUMP (Continued)
FUEL DELIVERY - DIESEL
14 - 65
pump. The Fuel Pump/Gear Pump is a low-pressure pump and produce pressures ranging from 551.5 kpa (80 psi) to 1241 kpa (180) psi. Fuel then enters the fuel injection pump. Low pressure fuel is then sup- plied to the FAC (Fuel Control Actuator).
The FAC is an electronically controlled solenoid valve. The ECM controls the amount of fuel that enters the high-pressure pumping chambers by open- ing and closing the FAC based on a demanded fuel pressure. The FPS (Fuel Pressure Sensor) on the fuel rail provides the actual fuel pressure. When the actuator is opened, the maximum amount of fuel is being supplied to the fuel injection pump. Any fuel that does not enter the injection pump is directed to the overflow valve. The overflow valve regulates how much excess fuel is used for lubrication of the pump and how much is returned to the tank through the drain manifold.
Fuel entering the injection pump is pressurized to between 300 - 1600 bar by three radial pumping chambers. The pressurized fuel is then supplied to the fuel rail.
DIAGNOSIS AND TESTING - FUEL INJECTION PUMP TIMING
With the Bosch injection pump,
there are no mechanical adjustments needed or necessary to accomplish fuel injection timing. All timing and fuel adjustments are electrically made by the engine mounted Engine Control Module (ECM).
REMOVAL
lines and fuel
CAUTION: Cleanliness cannot be overemphasized when handling or replacing diesel fuel system com- ponents. This especially includes the fuel injectors, high-pressure fuel injection pump. Very tight tolerances are used with these parts. Dirt contamination could cause rapid part wear and pos- sible plugging of fuel injector nozzle tip holes. This in turn could lead to possible engine misfire. Always wash/clean any fuel system component thoroughly before disassembly and then air dry. Cap or cover any open part after disassembly. Before assembly, examine each part for dirt, grease or other contaminants and clean if necessary. When installing new parts, lubricate them with clean engine oil or clean diesel fuel only.
(1) Disconnect both negative battery cables at both
batteries. Cover and isolate ends of both cables.
(2) Remove intake manifold air intake tube (above injection pump) and its rubber connector hose (Fig. 8).
(3) The Engine Control Module (ECM) is mounted to left side of engine (Fig. 9). Remove 5 ECM mount-
ing bolts and position ECM for injection pump removal. Do not disconnect wiring connectors from ECM.
(4) Remove cooling fan shroud. (5) Remove cooling fan assembly. (6) Remove accessory drive belt. (7) Thoroughly clean the rear of injection pump, and attachment points for its 3 fuel lines (Fig. 10). Also clean the opposite ends of these same 3 lines at their attachment points.
(8) Disconnect Fuel Control Actuator (FCA) electri-
cal connector at rear of injection pump (Fig. 11).
(9) Remove fuel
line (injection pump-to-overflow
valve).
housing).
(10) Remove fuel line (injection pump-to-fuel rail). (11) Remove fuel line (injection pump-to-fuel filter
(12) Remove fuel pump drive gear access cover (plate) with a 1/2 inch drive ratchet. Plate is threaded to timing gear cover (Fig. 12).
(13) Remove fuel pump drive gear mounting nut
and washer.
(14) Attach C3428B, or L4407A (or equivalent) gear puller (Fig. 13) to pump drive gear with 2 bolts, and separate gear from pump (a keyway is not used on this particular injection pump). Leave drive gear hanging loose within timing gear cover.
(15) Remove 3 injection pump mounting nuts (Fig.
14), and remove pump from engine.
Fig.8INTAKETUBEANDCONNECTINGHOSE
1 - MANIFOLD ABOVE HEATERS 2 - RUBBER CONNECTING HOSE 3 - METAL INTAKE TUBE 4 - CLAMPS (2)
FUEL DELIVERY - DIESEL
14 - 66
FUEL INJECTION PUMP (Continued)DR
Fig.9ECMREMOVAL/INSTALLATION
Fig.11FUELCONTROLACTUATOR
1 - ECM LOCATION 2 - ELECTRICAL CONNECTORS (2) 3 - CONNECTOR BOLTS 4 - ECM MOUNTING BOLTS (5) 5 - BOTTOM OF INJECTION PUMP
1 - ACTUATOR MOUNTING BOLTS 2 - FCA (FUEL CONTROL ACTUATOR) 3 - ACTUATOR ELECTRICAL CONNECTOR
Fig.10OVERFLOWVALVE
1 - BANJO BOLTS 2 - PUMP MOUNTING NUTS (3) 3 - FUEL INJECTION PUMP 4 - CASCADE OVERFLOW VALVE
Fig.12PUMPDRIVEGEARACCESSCOVER
1 - FRONT TIMING GEAR COVER 2 - GEAR ACCESS PLATE (COVER) 3 - HEX DRIVE (FOR COVER REMOVAL/INSTALLATION)
DR FUEL INJECTION PUMP (Continued)
FUEL DELIVERY - DIESEL
14 - 67
INSTALLATION
lines and fuel
CAUTION: Cleanliness cannot be overemphasized when handling or replacing diesel fuel system com- ponents. This especially includes the fuel injectors, high-pressure fuel injection pump. Very tight tolerances are used with these parts. Dirt contamination could cause rapid part wear and pos- sible plugging of fuel injector nozzle tip holes. This in turn could lead to possible engine misfire. Always wash/clean any fuel system component thoroughly before disassembly and then air dry. Cap or cover any open part after disassembly. Before assembly, examine each part for dirt, grease or other contaminants and clean if necessary. When installing new parts, lubricate them with clean engine oil or clean diesel fuel only.
Fig.13DRIVEGEARREMOVAL
1 - FRONT TIMING GEAR COVER 2 - GEAR PULLER TOOL
(1) Inspect pump mounting surfaces at pump and mounting flange for nicks, cuts or damage. Inspect o-ring surfaces for nicks, cuts or damage.
(2) Clean injection pump mounting flange at gear
housing. Also clean front of injection pump.
(3) Install new rubber o-ring into machined groove
(Fig. 14) at pump mounting area.
1 - PUMP DRIVE GEAR NUT 2 - WASHER 3 - PUMP DRIVE GEAR 4 - RUBBER O-RING 5 - FUEL INJECTION PUMP
Fig.14FUELINJECTIONPUMPREMOVAL/INSTALLATION
6 - PUMP MOUNTING NUTS (3) 7 - PUMP MOUNTING STUDS (3) 8 - O-RING MACHINED GROOVE 9 - FRONT TIMING GEAR COVER
FUEL DELIVERY - DIESEL
14 - 68
FUEL INJECTION PUMP (Continued)(4) Apply clean engine oil to injection pump
o-ring only.
The machined tapers on both injection pump shaft and injection pump gear must be abso- lutely dry, clean and free of any dirt or oil film. This will ensure proper gear-to-shaft tighten- ing.
(5) Clean pump gear and pump shaft at machined tapers with an evaporative type cleaner such as brake cleaner.
(6) Position injection pump to mounting flange on cover while aligning injection pump shaft
gear through back of injection pump gear. (7) After pump is positioned flat
to mounting flange, install 3 pump mounting nuts and tighten finger tight only. Do not attempt a final tightening at this time. Do not attempt to tighten (pull) pump to gear cover using mounting nuts. Dam- age to pump or gear cover may occur. The pump must be positioned flat to its mounting flange before attempting to tighten 3 mounting nuts.
(8) To prevent damage or cracking of components,
install and tighten nuts in the following sequence:
(a) Install injection pump shaft washer and nut
to pump shaft. Tighten nut finger tight only.
(b) Do preliminary (light) tightening of injection
pump shaft nut.
N·m (70.8 in. lbs.).
(c) Tighten 3 injection pump mounting nuts to 8
(d) Do a final tightening of pump shaft nut to
105 N·m (77 ft. lbs.). (9) Install drive gear access cover (plate) using a 1/2 inch drive ratchet. Plate is threaded to timing gear cover.
(10) Install Engine Control Module (ECM) to left
side of engine. (11) Install
fuel
line (injection pump-to-overflow
valve). Tighten bolts to 24 N·m (17 ft. lbs.) torque.
(12) Install fuel line (injection pump-to-fuel rail).
Tighten to 24 N·m (17 ft. lbs.) torque.
(13) Install fuel line (injection pump-to-fuel filter
housing). Tighten to 24 N·m (17 ft. lbs.) torque.
(14) Connect Fuel Control Actuator (FCA) electri-
cal connector to rear of injection pump.
(15) Install intake manifold air intake tube (above
injection pump). Tighten clamps.
(16) Install accessory drive belt. (17) Install cooling fan shroud. (18) Install cooling fan assembly. (19) Connect both negative battery cables to both
batteries.
(20) Check system for fuel or engine oil leaks.
DR
FUEL LEVEL SENDING UNIT / SENSOR DESCRIPTION
The fuel gauge sending unit (fuel level sensor) is attached to the side of the fuel tank module. The sending unit consists of a float, an arm, and a vari- able resistor track (card).
