pcm DODGE RAM 2003 Service Manual PDF

NOTE: If a PCM is replaced, the unique ªSecret
Keyº data must be transferred from the SKIM to the
PCM. This procedure requires the SKIM to be
placed in SECURED ACCESS MODE using the four
digit PIN code.
SENTRY KEY IMMOBILIZER SYSTEM
TRANSPONDER PROGRAMMING
Two programmed Sentry Key transponders are
included with the Sentry Key Immobilizer System
(SKIS) when it is shipped from the factory. The Sen-
try Key Immobilizer Module (SKIM) can be pro-
grammed to recognize up to six additional
transponders, for a total of eight Sentry Keys. The
following ªCustomer Learnº programming procedure
for the programming of additional transponders
requires access to at least two of the valid Sentry
Keys. If two valid Sentry Keys are not available, Sen-
try Key programming will require the use of a
DRBIIItscan tool.
CUSTOMER LEARN PROGRAMMING
(1) Obtain the additional Sentry Key transponder
blank(s) that are to be programmed for the vehicle.
Cut the additional Sentry Key transponder blanks to
match the ignition lock cylinder mechanical key
codes.
(2) Insert one of the two valid Sentry Key tran-
sponders into the ignition switch and turn the igni-
tion switch to the ON position.
(3) After the ignition switch has been in the ON
position for about three seconds, but no more than
fifteen seconds, cycle the ignition switch back to the
OFF position. Replace the first valid Sentry Key in
the ignition lock cylinder with the second valid Sen-
try Key and turn the ignition switch back to the ON
position. Both operations must be performed within
15 seconds.
(4) In approximately ten seconds the VTSS indica-
tor LED will start to flash to indicate that the sys-
tem has entered the ªCustomer Learnº programming
mode.
(5) Within approximately sixty seconds of entering
the ªCustomer Learnº programming mode, turn the
ignition switch to the OFF position, replace the valid
Sentry Key with a blank Sentry Key transponder,
and turn the ignition switch back to the ON position.
(6) In approximately ten seconds, the VTSS indica-
tor LED will stop flashing and stay on solid for
approximately three seconds and then turn OFF to
indicate that the blank Sentry Key transponder has
been successfully programmed. The SKIS will imme-
diately return to normal system operation following
exit from the ªCustomer Learnº programming mode.(7) Repeat this process for each additional Sentry
Key transponder blank to be programmed.
If any of the above steps is not completed in the
proper sequence, or within the allotted time, the
SKIS will automatically exit the ªCustomer Learnº
programming mode. The SKIS will also automatically
exit the ªCustomer Learnº programming mode if it
sees a non-blank Sentry Key transponder when it
should see a blank, if it has already programmed
eight valid Sentry Keys, or if the ignition switch is
turned to the OFF position for more than about fifty
seconds.
NOTE: While in Customer Learn mode (LED flash-
ing), the engine will not START and RUN.
PROGRAMMING BLANK SENTRY KEY
TRANSPONDERS WITH A DRBIIITSCAN TOOL
When programming a blank Sentry Key transpon-
der, the key blank must first be cut to match the
ignition lock cylinder. It will also be necessary to
enter the vehicle's four digit PIN code into the
DRBIIItscan tool to enter the Sentry Key Immobi-
lizer Module's (SKIM's) secured access mode.
NOTE: Once a Sentry Key is programmed to a par-
ticular vehicle, it cannot be transferred to another
vehicle.
Insert the blank key into the ignition and turn it to
the RUN position. Using the DRBIIItscan tool,
select ªTheft Alarm,º then ªSKIM,º then ªMiscella-
neous.º Select ªProgram New Key.º Enter the four
digit PIN code using the DRBIIIt. When program-
ming is completed, the SKIM will exit secured access
mode and the DRBIIItwill display the status of the
key. One of five different status messages may be dis-
played as follows:
²ªProgramming Successfulº is displayed if SKIM
Sentry Key programming succeeds.
²ªLearned Key in Ignitionº is displayed if the key
in the ignition has already been programmed into
that vehicle's SKIM.
²ª8 Keys Already Learned (At The Maximum)
Programming Not Doneº is displayed if eight keys
have already been programmed into the SKIM. In
this case, if a new key needs to be added due to a
lost or defective key, the ªErase All Keysº function
(requires entering secured access mode) has to be
performed. Then the customer's seven keys plus the
new key MUST be reprogrammed into the SKIM.
²ªProgramming Not Attemptedº is displayed after
an ªErase All Keysº function is executed.
²ªProgramming Key Failedº is displayed if fur-
ther diagnosis is required.
8Q - 4 VEHICLE THEFT SECURITYDR
VEHICLE THEFT SECURITY (Continued)

through the normally open contacts of the energized
wiper on/off relay and the normally open contacts of
the energized wiper high/low relay to the high speed
brush of the wiper motor, causing the wipers to cycle
at high speed.
When the Off position of the multi-function switch
control knob is selected, the instrument cluster sends
an electronic wiper switch off message to the FCM. If
the wiper motor was operating at high speed, the
FCM immediately de-energizes the wiper high/low
relay causing the wiper motor to return to low speed
operation. Then one of two events will occur. The
event that occurs depends upon the position of the
wiper blades on the windshield at the moment that
the control knob Off position is selected.
If the wiper blades are in the down position on the
windshield when the Off position is selected, the
park switch that is integral to the wiper motor is
closed to ground and provides a hard wired park
switch sense input to the FCM. The FCM then de-en-
ergizes the wiper on/off relay and the wiper motor
ceases to operate. If the wiper blades are not in the
down position on the windshield at the moment the
Off position is selected, the park switch is an open
circuit and the FCM keeps the wiper on/off relay
energized, which causes the wiper motor to continue
running at low speed until the wiper blades are in
the down position on the windshield and the park
switch input to the FCM is again closed to ground.
INTERMITTENT WIPE MODE
When the control knob on the control stalk of the
multi-function switch is moved to one of the Delay
interval positions the instrument cluster sends an
electronic wiper switch delay message to the FCM,
then the FCM electronic intermittent wipe logic cir-
cuit responds by calculating the correct length of
time between wiper sweeps based upon the selected
delay interval input. The FCM monitors the changing
state of the wiper motor park switch through a hard
wired park switch sense input. This input allows the
FCM to determine the proper intervals at which to
energize and de-energize the wiper on/off relay to
operate the wiper motor intermittently for one low
speed cycle at a time.
The FCM logic is also programmed to provide vehi-
cle speed sensitivity to the selected intermittent wipe
delay intervals. In order to provide this feature the
FCM monitors electronic vehicle speed messages
from the Powertrain Control Module (PCM) and dou-
bles the selected delay interval whenever the vehicle
speed is about sixteen kilometers-per-hour (ten miles-
per-hour) or less.PULSE WIPE MODE
When the control knob on the control stalk of the
multi-function switch is depressed to the momentary
Wash position for less than about one-half second,
the instrument cluster sends an electronic washer
switch message to the FCM, then the FCM the ener-
gizes the wiper on/off relay for one complete wipe
cycle. The FCM de-energizes the relay when the state
of the park switch sense changes to ground, parking
the wiper blades near the base of the windshield.
WASH MODE
When the control knob on the control stalk of the
multi-function switch is depressed to the momentary
Wash position for more than about one-half second,
the instrument cluster sends an electronic washer
switch message to the FCM, then the FCM directs
battery current to the washer pump/motor unit. This
will cause the washer pump/motor unit to be ener-
gized for as long as the Wash switch is held closed up
to about thirty seconds, and to de-energize when the
front Wash switch is released.
When the control knob is depressed to the momen-
tary Wash position while the wiper system is operat-
ing in one of the Delay interval positions, the washer
pump/motor operation is the same. However, the
FCM also energizes the wiper on/off relay to override
the selected delay interval and operate the wiper
motor in a continuous low speed mode for as long as
the control knob is held depressed, then de-energizes
the relay and reverts to the selected delay mode
interval several wipe cycles after the control knob is
released. If the control knob is held depressed for
more than about thirty seconds, the FCM will sus-
pend washer pump/motor operation until the knob is
released for about two seconds, then cycled back to
the Wash position.
WIPE-AFTER-WASH MODE
When the control knob on the control stalk of the
multi-function switch is depressed to the momentary
Wash position for more than about one-half second
while the wiper system is not operating, the instru-
ment cluster sends an electronic washer switch mes-
sage to the FCM, then the FCM the directs battery
current to the washer pump/motor unit and energizes
the wiper on/off relay. This will cause the washer
pump/motor unit to be energized and operate the
wiper motor in a continuous low speed mode for as
long as the Wash switch is held closed up to about
thirty seconds. When the control knob is released,
the FCM de-energizes the washer pump/motor unit,
but allows the wiper motor to operate for several
additional wipe cycles before it de-energizes the
wiper on/off relay and parks the wiper blades near
the base of the windshield.
DRWIPERS/WASHERS 8R - 5
WIPERS/WASHERS (Continued)

CRANKSHAFT POSITION SENSOR - BLACK 3 WAY
CAV CIRCUIT FUNCTION
1 K24 18GY/BK CRANKSHAFT POSITION SENSOR SIGNAL
1 K7 18OR (5.7L) 5 VOLT SUPPLY
1 K24 18GY/BK (4.7L/) CKP SIGNAL
2 K4 18BK/LB (3.7L/4.7L/5.7L) SENSOR GROUND
2 K4 20BK/LB (5.9L) SENSOR GROUND
3 K7 18OR (3.7L/4.7L) 5 VOLT SUPPLY
3 K24 18GY/BK (5.7L) CKP SIGNAL
3 K7 20OR (5.9L) 5 VOLT SUPPLY
CYLINDER LOCK SWITCH-DRIVER (PREMIUM) - BLACK 2 WAY
CAV CIRCUIT FUNCTION
1 G73 20LG/OR DRIVER CYLINDER LOCK SWITCH MUX
2 Z70 20BK/LG GROUND
CYLINDER LOCK SWITCH-PASSENGER (PREMIUM) - LT GRAY 2 WAY
CAV CIRCUIT FUNCTION
1 G72 20DG/OR PASSENGER CYLINDER LOCK SWITCH MUX
2 Z69 20BK/LG GROUND
DATA LINK CONNECTOR - BLACK 16 WAY
CAV CIRCUIT FUNCTION
1- -
2 D25 20LB/VT PCI BUS
3- -
4 Z305 18BK/DG GROUND
5 Z306 18OR/BK GROUND
6- -
7 D21 18PK SCI TRANSMIT (PCM)
8- -
9 D6 18PK/LB SCI RECEIVE (TCM)
10 - -
11 - -
12 D20 20LG SCI RECEIVE (PCM)
13 - -
14 - -
15 D15 18WT/DG SCI TRANSMIT (TCM)
16 M1 18PK FUSED B(+)
DR8W-80 CONNECTOR PIN-OUTS 8W - 80 - 49

POWERTRAIN CONTROL MODULE C1 (NGC) - BLACK 38 WAY
CAV CIRCUIT FUNCTION
1 K98 18LB/RD COIL CONTROL NO.8
2- -
3 K97 18BR COIL CONTROL NO.7
4 K28 18GY/LB INJECTOR CONTROL NO.8
5 K26 18VT/TN INJECTOR CONTROL NO.7
6- -
7- -
8 B222 20DG/WT (5.7L) VEHICLE SPEED SIGNAL NO. 2
9 Z81 16BK/TN GROUND
10 - -
11 Y135 18LG/BK FUSED IGNITION SWITCH OUTPUT
12 A51 16RD/WT (4.7) FUSED IGNITION SWITCH OUTPUT (OFF-RUN-START)
12 Y135 LG/BK (5.7) FUSED IGNITION SWITCH OUTPUT
13 B22 20DG/YL (5.7L) VEHICLE SPEED SIGNAL NO.1
13 G7 18WT/OR (4.7L) VEHICLE SPEED SIGNAL
14 - -
15 - -
16 - -
17 - -
18 Z82 16BK/TN GROUND
19 - -
20 G60 18GY/YL OIL PRESSURE SIGNAL
21 C18 18DB A/C PRESSURE SIGNAL
22 G31 18VT/LG AAT SIGNAL
23 - -
24 - -
25 D20 18LG SCI RECEIVE (PCM)
26 D6 18PK/LB SCI RECEIVE (TCM)
27 K6 18VT/WT (4.7L) 5-VOLT SUPPLY
28 - -
29 A14 20RD/WT FUSED B+
30 A41 16YL FUSED IGNITION SWITCH OUTPUT
31 K141 18TN/WT O2 1/2 SIGNAL
32 Y213 18PK/LB O2 RETURN UPSTREAM
33 K341 18TN/WT (4.7L) O2 2/2 SIGNAL
34 - -
35 - -
36 D21 18PK SCI TRANSMIT (PCM)
37 D15 18WT/DG (4.7L) SCI TRANSMIT (TCM)
38 D25 20VT/BR PCI BUS
8W - 80 - 88 8W-80 CONNECTOR PIN-OUTSDR

INSPECTION
(1) Inspect oil drain plug and plug hole for
stripped or damaged threads. Repair as necessary.
(2) Inspect the oil pan mounting flange for bends
or distortion. Straighten flange, if necessary.
INSTALLATION
(1) Clean the oil pan gasket mating surface of the
bedplate and oil pan.
(2) Inspect integrated oil pan gasket, and replace
as necessary.
(3) Position the integrated oil pan gasket/windage
tray assembly.
(4) Install the oil pickup tube
(5) Install the mounting bolt and nuts. Tighten
nuts to 28 N´m (20 ft. lbs.).
(6) Position the oil pan and install the mounting
bolts. Tighten the mounting bolts to 15 N´m (11 ft.
lbs.) in the sequence shown (Fig. 75).
(7) Lower the engine into mounts using special
tool # 8534.
(8) Install both the left and right side engine
mount through bolts. Tighten the nuts to 68 N´m (50
ft. lbs.).
(9) Remove special tool # 8534.
(10) Install structural dust cover, if equipped.
(11) Install the front crossmember(Refer to 13 -
FRAME & BUMPERS/FRAME/FRONT CROSS-
MEMBER - INSTALLATION).
(12) Fill engine oil.
(13) Reconnect the negative battery cable.
(14) Start engine and check for leaks.
OIL PRESSURE SENSOR/
SWITCH
DESCRIPTION
The 3±wire, solid-state engine oil pressure sensor
(sending unit) is located in an engine oil pressure
gallery.
OPERATION
The oil pressure sensor uses three circuits. They
are:²A 5±volt power supply from the Powertrain Con-
trol Module (PCM)
²A sensor ground through the PCM's sensor
return
²A signal to the PCM relating to engine oil pres-
sure
The oil pressure sensor has a 3±wire electrical
function very much like the Manifold Absolute Pres-
sure (MAP) sensor. Meaning different pressures
relate to different output voltages.
A 5±volt supply is sent to the sensor from the PCM
to power up the sensor. The sensor returns a voltage
signal back to the PCM relating to engine oil pres-
sure. This signal is then transferred (bussed) to the
instrument panel on either a CCD or PCI bus circuit
(depending on vehicle line) to operate the oil pressure
gauge and the check gauges lamp. Ground for the
sensor is provided by the PCM through a low-noise
sensor return.
Fig. 75 Oil Pan Mounting Bolt Sequence
9 - 66 ENGINE - 3.7LDR
OIL PAN (Continued)

OIL PRESSURE SENSOR/
SWITCH
DESCRIPTION
DESCRIPTION
The 3±wire, solid-state engine oil pressure sensor
(sending unit) is located in an engine oil pressure
gallery.
DESCRIPTION
The 3±wire, electrical/mechanical engine oil pres-
sure sensor (sending unit) is located in an engine oil
pressure gallery.
OPERATION
OPERATION
The oil pressure sensor uses three circuits. They
are:
²A 5±volt power supply from the Powertrain Con-
trol Module (PCM)
²A sensor ground through the PCM's sensor
return
²A signal to the PCM relating to engine oil pres-
sure
The oil pressure sensor has a 3±wire electrical
function very much like the Manifold Absolute Pres-
sure (MAP) sensor. Meaning different pressures
relate to different output voltages.
A 5±volt supply is sent to the sensor from the PCM
to power up the sensor. The sensor returns a voltage
signal back to the PCM relating to engine oil pres-
sure. This signal is then transferred (bussed) to the
instrument panel on either a CCD or PCI bus circuit
(depending on vehicle line) to operate the oil pressure
gauge and the check gauges lamp. Ground for the
sensor is provided by the PCM through a low-noise
sensor return.
OPERATION
The oil pressure sensor uses two circuits. They are:
²A signal to the PCM relating to engine oil pres-
sure
²A sensor ground through the PCM's sensor
return
The oil pressure sensor returns a voltage signal
back to the PCM relating to engine oil pressure. This
signal is then transferred (bussed) to the instrument
panel on a CCD bus circuit to operate the oil pres-
sure gauge and the check gauges lamp. Ground for
the sensor is provided by the PCM through a low-
noise sensor return.
REMOVAL
(1) Disconnect the negative cable from the battery.
(2) Raise vehicle on hoist.
(3) Remove front splash shield.
(4) Disconnect oil pressure sender wire (Fig. 100).
(5) Remove the pressure sender (Fig. 100).
INSTALLATION
(1) Install oil pressure sender.
(2) Connect oil pressure sender wire.
(3) Install front splash shield.
(4) Lower vehicle.
(5) Connect the negative battery cable.
OIL PUMP
REMOVAL
(1) Remove the oil pan and pick-up tube (Refer to
9 - ENGINE/LUBRICATION/OIL PAN - REMOVAL).
(2) Remove the timing chain cover (Refer to 9 -
ENGINE/VALVE TIMING/TIMING BELT / CHAIN
COVER(S) - REMOVAL).
(3) Remove the timing chains and tensioners
(Refer to 9 - ENGINE/VALVE TIMING/TIMING
BELT/CHAIN AND SPROCKETS - REMOVAL).
(4) Remove the four bolts, primary timing chain
tensioner and the oil pump.
Fig. 100 OIL PRESSURE SENDING UNIT
1 - BELT
2 - OIL PRESSURE SENSOR
3 - OIL FILTER
4 - ELEC. CONNECTOR
9 - 154 ENGINE - 4.7LDR

(2) Remove fuel pump relay from Power Distribu-
tion Center (PDC). For location of relay, refer to label
on underside of PDC cover.
(3) Start and run engine until it stalls.
(4) Attempt restarting engine until it will no
longer run.
(5) Turn ignition key to OFF position.
CAUTION: Steps 1, 2, 3 and 4 must be performed to
relieve high pressure fuel from within fuel rail. Do
not attempt to use following steps to relieve this
pressure as excessive fuel will be forced into a cyl-
inder chamber.
(6) Unplug connector from any fuel injector.
(7) Attach one end of a jumper wire with alligator
clips (18 gauge or smaller) to either injector terminal.
(8) Connect other end of jumper wire to positive
side of battery.(9) Connect one end of a second jumper wire to
remaining injector terminal.
CAUTION: Powering an injector for more than a few
seconds will permanently damage the injector.
(10) Momentarily touch other end of jumper wire
to negative terminal of battery for no more than a
few seconds.
(11) Place a rag or towel below fuel line quick-con-
nect fitting at fuel rail.
(12) Disconnect quick-connect fitting at fuel rail.
Refer to Quick-Connect Fittings.
(13) Return fuel pump relay to PDC.
(14) One or more Diagnostic Trouble Codes (DTC's)
may have been stored in PCM memory due to fuel
pump relay removal. The DRBtscan tool must be
used to erase a DTC.
SPECIFICATIONS
FUEL SYSTEM PRESSURE
339 kPa +/- 34 kPa (49.2 psi +/- 2 psi).
TORQUE - FUEL SYSTEM
DESCRIPTION N-m Ft. Lbs. In. Lbs.
Accelerator Pedal Bracket
Mounting12 - 105
Accelerator Pedal Position
Sensor Bracket-to-Battery
Tray Bolts3-30
Crankshaft Position
Sensor - 3.7L28 21 -
Crankshaft Position
Sensor - 4.7L28 21 -
Crankshaft Position
Sensor - 5.7L12 - 105 (+/-20)
Crankshaft Position
Sensor - 5.9L8-70
Crankshaft Position
Sensor - 8.0L8-70
Camshaft Position Sensor
- 3.7L12 - 106
Camshaft Position Sensor
- 4.7L12 - 106
Camshaft Position Sensor
- 5.7L12 9 105 (+/-) 20
Camshaft Position Sensor
- 8.0L6-50
DRFUEL DELIVERY - GAS 14 - 3
FUEL DELIVERY - GAS (Continued)

DESCRIPTION N-m Ft. Lbs. In. Lbs.
Map Sensor Mounting
Screws - 4.7L3-25
Map Sensor Mounting
Screws - 5.9L3-25
Map Sensor Mounting
Screws - 8.0L2-20
PCM-to-Mounting Bracket
Mounting Screws4-35
Power Steering Pressure
Switch - 3.7L14-22 - 124-195
Power Steering Pressure
Switch - 4.7L14-22 - 124-195
TPS Mounting Screws -
3.7L7-60
TPS Mounting Screws -
4.7L7-60
TPS Mounting Screws -
5.9L7-60
TPS Mounting Screws -
8.0L7-60
Throttle Body Mounting
Bolts - 3.7L11 - 100
Throttle Body Mounting
Bolts - 4.7L12 - 105
Throttle Body Mounting
Bolts - 5.7L12 - 105
Throttle Body Mounting
Bolts - 5.9L23 - 200
Throttle Body Mounting
Bolts - 8.0L22 - 192
Oxygen Sensors 30 22 -
SPECIAL TOOLS
FUEL SYSTEM
FUEL PRESSURE TESTER - #8978
TEST KIT, FUEL PRESSURE, 8.0L ENGINE - #5069
DRFUEL DELIVERY - GAS 14 - 5
FUEL DELIVERY - GAS (Continued)

FUEL FILTER/PRESSURE
REGULATOR
DESCRIPTION
A combination fuel filter and fuel pressure regula-
tor (Fig. 2) is used on all engines. It is located on the
top of the fuel pump module. A separate frame
mounted fuel filter is not used with any engine.
Both fuel filters (at bottom of fuel pump module
and within fuel pressure regulator) are designed for
extended service. They do not require normal sched-
uled maintenance. Filters should only be replaced if
a diagnostic procedure indicates to do so.
OPERATION
Fuel Pressure Regulator Operation:The pres-
sure regulator is a mechanical device that is not con-
trolled by engine vacuum or the Powertrain Control
Module (PCM).
The regulator is calibrated to maintain fuel system
operating pressure of approximately 339 kPa   34
kPa (49.2 psi   5 psi) at the fuel injectors. It contains
a diaphragm, calibrated springs and a fuel return
valve. The internal fuel filter (Fig. 2) is also part of
the assembly.
Fuel is supplied to the filter/regulator by the elec-
tric fuel pump through an opening tube at the bot-
tom of filter/regulator (Fig. 2).
The regulator acts as a check valve to maintain
some fuel pressure when the engine is not operating.
This will help to start the engine. A second check
valve is located at the outlet end of the electric fuel
ADAPTERS, FUEL PRESSURE TEST, 8.0L - #6539
AND/OR #6631
SPANNER WRENCH - #6856
FITTING, AIR METERING - #6714
O2S (OXYGEN SENSOR) REMOVER/INSTALLER -
#C-4907
Fig. 2 SIDE VIEW - FILTER/REGULATOR
1 - INTERNAL FUEL FILTER
2 - FUEL FLOW TO FUEL INJECTORS
3 - FUEL FILTER/FUEL PRESSURE REGULATOR
4 - EXCESS FUEL BACK TO TANK
5 - FUEL INLET
6 - RUBBER GROMMET
7 - TOP OF PUMP MODULE
14 - 6 FUEL DELIVERY - GASDR
FUEL DELIVERY - GAS (Continued)

pump.Refer to Fuel Pump - Description and
Operation for more information.
If fuel pressure at the pressure regulator exceeds
approximately 49.2 psi, an internal diaphragm opens
and excess fuel pressure is routed back into the tank
through the bottom of pressure regulator.
Both fuel filters (at bottom of fuel pump module
and within fuel pressure regulator) are designed for
extended service. They do not require normal sched-
uled maintenance. Filters should only be replaced if
a diagnostic procedure indicates to do so.
FUEL LEVEL SENDING UNIT /
SENSOR
DESCRIPTION
The fuel gauge sending unit (fuel level sensor) is
attached to the side of the fuel pump module. The
sending unit consists of a float, an arm, and a vari-
able resistor track (card).
OPERATION
The fuel pump module has 4 different circuits
(wires). Two of these circuits are used for the fuel
gauge sending unit for fuel gauge operation, and for
certain OBD II emission requirements. The other 2
wires are used for electric fuel pump operation.
For Fuel Gauge Operation:A constant current
source is supplied to the resistor track on the fuel
gauge sending unit. This is fed directly from the
Powertrain Control Module (PCM).NOTE: For
diagnostic purposes, this 12V power source can
only be verified with the circuit opened (fuel
pump module electrical connector unplugged).
With the connectors plugged, output voltages
will vary from about 0.6 volts at FULL, to about
8.6 volts at EMPTY (about 8.6 volts at EMPTY
for Jeep models, and about 7.0 volts at EMPTY
for Dodge Truck models).The resistor track is
used to vary the voltage (resistance) depending on
fuel tank float level. As fuel level increases, the float
and arm move up, which decreases voltage. As fuel
level decreases, the float and arm move down, which
increases voltage. The varied voltage signal is
returned back to the PCM through the sensor return
circuit.
Both of the electrical circuits between the fuel
gauge sending unit and the PCM are hard-wired (not
multi-plexed). After the voltage signal is sent from
the resistor track, and back to the PCM, the PCM
will interpret the resistance (voltage) data and send
a message across the multi-plex bus circuits to the
instrument panel cluster. Here it is translated into
the appropriate fuel gauge level reading. Refer to
Instrument Panel for additional information.For OBD II Emission Monitor Requirements:
The PCM will monitor the voltage output sent from
the resistor track on the sending unit to indicate fuel
level. The purpose of this feature is to prevent the
OBD II system from recording/setting false misfire
and fuel system monitor diagnostic trouble codes.
The feature is activated if the fuel level in the tank
is less than approximately 15 percent of its rated
capacity. If equipped with a Leak Detection Pump
(EVAP system monitor), this feature will also be acti-
vated if the fuel level in the tank is more than
approximately 85 percent of its rated capacity.
REMOVAL
The fuel level sending unit (fuel level sensor) and
float assembly is located on the side of the fuel pump
module (Fig. 3).
(1) Remove fuel pump module from fuel tank.
Refer to Fuel Pump Module Removal/Installation.
(2) To remove sending unit from pump module, lift
on plastic locking tab (Fig. 4) while sliding sending
unit tracks.
(3) Disconnect 4±wire electrical connector (Fig. 3)
from fuel pump module. Separate necessary sending
unit wiring from connector using terminal pick /
removal tool. Refer to Special Tools in 8W Wiring for
tool part numbers.
Fig. 3 LOCATION - FUEL GAUGE SENDING UNIT
1 - FUEL FILTER / FUEL PRESSURE REGULATOR
2 - FUEL PUMP MODULE ASSEMBLY
3 - 4-WAY ELEC. CONNECT.
4 - FLOAT ARM
5 - ELEC. FUEL PUMP
6 - INLET FILTER
7 - FUEL GAUGE SENDING UNIT
8 - GASKET (SEAL)
DRFUEL DELIVERY - GAS 14 - 7
FUEL FILTER/PRESSURE REGULATOR (Continued)