jump start DODGE RAM 1999 Service Repair Manual

knob pointer) is flush with base of A/C-heater control panel.
5) Rotate temperature control knob to its full clockwise
stop. Release knob. Knob pointer should be aimed at end of Red stripe.
If knob is pointed at end of Red stripe, go to next step. If knob is
not pointed at end of Red stripe, go back to step 2) and repeat
adjustment procedure.
6) Rotate temperature control knob to its full
counterclockwise stop. Release knob. If knob springs back, self-
adjuster clip securing temperature control cable to blend-air door
lever is improperly installed. See TEMPERATURE CONTROL CABLE R & I. If
knob does not spring back, temperature control cable adjustment is
complete.
TESTING
* PLEASE READ THIS FIRST *
WARNING: To avoid injury from accidental air bag deployment, read and
carefully follow all SERVICE PRECAUTIONS and DISABLING &
ACTIVATING AIR BAG SYSTEM procedures in AIR BAG SYSTEM SAFETY
article.
A/C-HEATER CONTROL PANEL TEST
1) Connect a vacuum gauge in line with Black A/C-heater
vacuum supply hose, located at tee near power brake booster (Dakota)
or in engine compartment (Durango and Ram Pickup). Position gauge so
it can be viewed from passenger compartment.
2) Start engine. While observing gauge, rotate mode control
knob to each mode position (one position at a time). Pause after each
selection. Test gauge should drop, then return to 8 in. Hg shortly
after each selection is made. If gauge reading is as specified, go to
next step. If gauge reading is not as specified, check for vacuum leak
in vacuum lines or A/C-heater control panel.
3) Move temperature control knob quickly to full hot and full
cold positions. A distinct sound of blend-air door hitting its stops
should be heard. No spring-back of knob should exist.
4) If temperature control knob operates as specified,
temperature control system is okay. On Dakota and Durango, if
temperature control knob does not operate as specified, check
condition, routing, installation, and adjustment of temperature
control cable. See TEMPERATURE CONTROL CABLE ADJUSTMENT . Also check
blend air door for proper installation, obstructions, or faulty seals.
A/C SYSTEM PERFORMANCE
1) Park vehicle out of direct sunlight. Ensure ambient
temperature is at least 70F (21C). Connect tachometer and manifold
gauge set to vehicle. Turn A/C on. Turn mode control to panel and
recirculated air positions, temperature control lever to maximum
cooling, and blower to high.
2) Start engine and allow it to run at 1000 RPM, with A/C
compressor clutch engaged. Engine should be at operating temperature
with doors, windows, and hood closed. Insert thermometer into left
center air outlet.
3) Run engine and operate system for 5 minutes. The A/C
compressor clutch may cycle, depending on temperature. If A/C
compressor clutch cycles, stop engine and disconnect negative battery
cable. Remove clutch cycling pressure switch connector. Place a jumper
wire across terminals of clutch cycling pressure switch harness
connector.
4) Connect negative battery cable. Turn A/C on. Start and

control panel and blower motor.
Fig. 3: Identifying Blower Motor Switch Connector Terminals (Typical)\
Courtesy of Chrysler Corp.
Rear (Durango)
1) Disconnect negative battery cable. Remove rear blower
motor switch located in headliner. See BLOWER MOTOR SWITCH (REAR)
under REMOVAL & INSTALLATION. Disconnect rear blower motor switch
connector. Using an ohmmeter, check continuity between rear blower
motor switch connector Black wire and ground. If continuity exists, go
to next step. If continuity does not exist, repair open in Black wire
between rear blower motor switch connector and ground connector
located at left rear of vehicle body.
2) Place blower motor switch knob to any position except OFF.
Using an ohmmeter, check for continuity between rear blower motor
switch connector Black wire and Black/Light Blue wire, and
Black/Orange wire and Dark Green wire while rotating blower motor
switch.
3) If continuity does not exist at any terminal, replace
faulty blower motor switch. If continuity exists as specified, check
for open in circuits between blower motor switch and blower motor
resistor. Also check for an open in circuit between blower motor
switch connector and blower motor relay.
CLUTCH CYCLING PRESSURE SWITCH
Dakota & Ram Pickup
1) Locate clutch cycling pressure switch on side or top of
A/C accumulator. Ensure clutch cycling pressure switch is properly
installed on A/C accumulator fitting. Ensure system pressure is
correct. See A/C SYSTEM PERFORMANCE test.
2) Start and run engine with A/C on. If clutch cycles, turn
engine off and disconnect negative battery cable. Disconnect clutch
cycling pressure switch connector. Place a jumper wire across
terminals of clutch cycling pressure switch harness connector. Connect
negative battery cable. Connect manifold gauge set. Set A/C-heater

1) Locate low pressure cut-out switch located on suction
line, near firewall. Ensure system pressure is correct. See
A/C SYSTEM PERFORMANCE test. Disconnect negative battery cable.
Disconnect low pressure cut-out switch connector.
2) Place a jumper wire across terminals of low pressure cut-
out switch harness connector. Connect negative battery cable. Connect
manifold gauge set. Set A/C-heater controls to A/C. Start and operate
engine at idle speed.
3) Using an ohmmeter, check for continuity between switch
terminals. Continuity should exist when suction pressure reading is
between 13-27 psi (.9-1.9 kg/cm
). Continuity should not exist when
suction pressure reading is 10 psi (.7 kg/cm) or lower. If switch is
okay, repair open or short in Brown wire between low pressure cut-out
switch and PCM. If switch is not okay, replace faulty low pressure
cut-out switch.
REMOVAL & INSTALLATION
* PLEASE READ THIS FIRST *
WARNING: To avoid injury from accidental air bag deployment, read and
carefully follow all SERVICE PRECAUTIONS and DISABLING &
ACTIVATING AIR BAG SYSTEM procedures in AIR BAG SYSTEM SAFETY
article.
A/C-HEATER ASSEMBLY
Removal (Dakota & Durango - Front)
1) Disconnect negative battery cable. Drain cooling system.
Discharge A/C system, using approved refrigerant recovery/recycling
equipment. Disconnect refrigerant lines from evaporator and plug or
cover all openings in A/C system. Remove instrument panel. See
INSTRUMENT PANEL .
2) In engine compartment, disconnect heater hoses. Remove 4
A/C-heater assembly nuts from engine compartment firewall. Inside
vehicle, remove A/C-heater assembly support brace screw, and swing
support brace out of way. Move passenger seat rearward.
3) Carefully pull A/C-heater assembly rearward until studs
and heater core tubes clear firewall. Lower A/C-heater assembly and
rotate assembly until studs are facing downward. Remove A/C-heater
assembly from vehicle. See Fig. 4.
4) Place A/C-heater assembly on work bench with assembly
housing cover facing down. Remove 2 screws securing A/C-heater
assembly housing cover to blower motor housing cover. Unplug vacuum
harness connector from panel/defrost door actuator.
5) Remove floor duct from A/C-heater assembly housing. Remove
2 screws securing A/C-heater assembly housing cover to lower housing
near floor outlet. Turn assembly over. Disengage vacuum harness
retainer and vacuum harness. Remove 13 screws securing housing cover.
6) Remove blend-air door lever. Gently pry panel-defrost door
lever off. Pull up on A/C-heater assembly housing cover far enough to
separate cover sealant and remove cover.
Installation
Ensure blower motor housing cover sealant is in place and in
good condition. To complete installation, reverse removal procedure.

step.
4) Observe AIR BAG warning light. Turn ignition off and wait
5 minutes. After 5 minutes, turn ignition on (engine off). If AIR BAG
warning light comes on for 6 to 8 seconds, replace ACM. If AIR BAG
warning light does not come on for 6 to 8 seconds, replace instrument
cluster.
REPAIRING PAD SWITCH
NOTE: Perform AIR BAG VERIFICATION TEST after
all repairs. Each time a connector is disconnected, inspect
it to ensure it is in good condition. Always focus on circuit
being tested. Dirt, water and corrosion, are most common
problems in connectors. Due to manufacturer changes in wire
colors, use terminal identification whenever possible.
1) Using DRB, read active DTCs. If DRB displays LOSS OF
IGNITION RUN/START, go to LOSS OF IGNITION RUN/START. If DRB does not
display LOSS OF IGNITION RUN/START, go to next step.
2) Disconnect PAD switch 2-pin connector. Using a voltmeter,
check voltage between PAD switch 2-pin connector terminals No. 1
(Light Green/Yellow wire) and No. 2 (Black wire). If voltage is less\
than 10 volts, repair open in Light Green/Yellow wire. If voltage is
more than 10 volts, go to next step.
3) Turn ignition off. Using an ohmmeter, check resistance
between ground and PAD switch connector terminal No. 2 (Black wire).
If resistance is more than 5 ohms, repair open in Black wire. If
resistance is less than 5 ohms, replace PAD switch.
PAD SWITCH INDICATOR PROBLEMS
1) If PAD switch off indicator fails to illuminate in OFF
position, go to next step. If PAD switch off indicator does not fail
to illuminate in OFF position, go to step 5).
2) Using DRB, read active DTCs. If DRB displays LOSS OF
IGNITION RUN/START, go to diagnostic test for that DTC. If DRB does
not display LOSS OF IGNITION RUN/START, go to next step.
3) Disconnect PAD switch 2-pin connector. Turn ignition on.
Measure voltage between ground and PAD switch 2-pin connector Light
Green/Yellow wire. If voltage is more than 10 volts, go to next step.
If voltage is less than 10 volts, repair open in Light Green/Yellow
wire.
4) Turn ignition off. Measure resistance between ground and
PAD switch 2-pin connector Black/Pink wire. If resistance is less than
5 ohms, replace PAD switch. If resistance is more than 5 ohms, repair
open in Black/Pink wire.
5) Ensure battery is fully charged. Using DRB, read and
record both active and stored code(s). Erase stored codes. Check for
active DTC(s) in either PAD switch position. If PAD switch off
indicator illuminates in ON position, replace PAD switch. If PAD
switch off indicator does not illuminate in ON position, test
complete.
AIR BAG VERIFICATION TEST
1) Remove all jumper wires. Reconnect all previously
disconnected components (except battery). Turn ignition on and
reconnect battery. Connect DRB to data link connector. Using DRB,
erase stored codes.
2) Turn ignition off and wait 15 seconds before turning
ignition on. Wait one minute. Read active codes. If DRB displays any
active codes, perform appropriate diagnostic test. If DRB does not
display any active codes, go to next step.

6) Using DRB in voltmeter mode, check voltage at ACM
connector terminal No. 22 (White/Black wire). If voltage is 1.8-2.6
volts, replace ACM. If voltage is not 1.8-2.6 volts, repair open in
White/Black wire.
OPEN FUSED IGNITION SWITCH OUTPUT (RUN/START) CKT
NOTE: Perform COMPONENT VERIFICATION TEST under DIAGNOSTIC TESTS
after all repairs. Each time a connector is disconnected,
inspect it to ensure it is in good condition. Always focus on
circuit being tested. Dirt, water and corrosion, are most
common problems in connectors. Due to manufacturer changes in
wire colors, use terminal identification whenever possible.
1) Turn ignition on (engine off). Using DRB in voltmeter
mode, probe output side (Dark Blue wire) of fuse No. 19 located in
junction block. If voltage is less than 10 volts, repair open in Dark
Blue wire. If voltage is more than 10 volts, go to next step.
2) Turn ignition off and wait 2 minutes before proceeding.
Using DRB in ohmmeter mode, probe fused side (Light Green/Yellow wire)\
of fuse No. 19 located in junction block. If resistance is less than 5
ohms, go to next step. If resistance is more than 5 ohms, go to step
4).
3) Disconnect ACM connector. Using DRB in ohmmeter mode,
probe fused side (Light Green/Yellow wire) of fuse No. 19 located in
junction block. If resistance is less than 5 ohms, repair short to
ground in Light Green/Yellow wire an replace fuse No. 19. If
resistance is more than 5 ohms, replace ACM and fuse No. 19.
4) Turn ignition off and wait 2 minutes before proceeding.
Disconnect ACM. Using an ohmmeter, check resistance between ACM
connector terminal No. 14 (Light Green/Yellow wire) and fused side
(Light Green/Yellow wire) of fuse No. 19 located in junction block. If\
resistance is more than 5 ohms, repair open in Light Green/Yellow wire
and replace fuse No. 19. If resistance is less than 5 ohms, go to next
step.
5) Reconnect ACM connector. Turn ignition on (engine off).
replace fuse No. 19. Perform appropriate diagnostic test under
DIAGNOSTIC TESTS.
NO RESPONSE FROM POWERTRAIN CONTROL MODULE
NOTE: Perform COMPONENT VERIFICATION TEST under DIAGNOSTIC TESTS
after all repairs. Each time a connector is disconnected,
inspect it to ensure it is in good condition. Always focus on
circuit being tested. Dirt, water and corrosion, are most
common problems in connectors. Due to manufacturer changes in
wire colors, use terminal identification whenever possible.
1) If engine does not run, repair as required. If engine
runs, disconnect Powertrain Control Module (PCM) connectors. Connect a\
jumper wire between ground and PCM Gray connector terminal C30
(Violet/Brown wire). Using DRB, perform CCD bus test. If DRB does not
display SHORT TO GROUND, repair open Violet/Brown wire. If DRB
displays SHORT TO GROUND, go to next step.
2) Connect a jumper wire between ground and PCM Gray
connector terminal C28 (White/Black wire). Using DRB, perform CCD bus
test. If DRB does not display SHORT TO GROUND, repair open White/Black
wire. If DRB displays SHORT TO GROUND, replace PCM.
REPAIRING SHORT TO BATTERY
NOTE: Perform COMPONENT VERIFICATION TEST under DIAGNOSTIC TESTS
after all repairs. Each time a connector is disconnected,

Minimum Compression Pressure
Dakota
2.5L ........................................................ (1)
3.9L, 5.2L & 5.9L ............................. 100 psi (690 kPa)\
Durango ........................................ 100 psi (690 kPa)\
Ram Pickup ..................................... 100 psi (690 kPa)\
Ram Van Ram Wagon .............................. 100 psi (690 kPa)\
Maximum Variation Between Cylinders ............................ ( 1)
( 1) - Information is not available from manufacturer.









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FUEL SYSTEM
FUEL PRESSURE RELEASE
WARNING: Fuel system is under high pressure. ALWAYS release fuel
pressure before attempting to open system for testing or
component replacement. DO NOT allow fuel to flow onto engine
or electrical parts while testing fuel system components.
Vehicles With Fuel Rail Test Port
1) Loosen fuel tank filler cap. Ensure ignition is off.
Remove protective cap from fuel rail test port.
2) Place one end of Fuel Pressure Release Hose (C-4799-1)
into an approved fuel container. Attach remaining end of hose to fuel
rail test port. Use care, as fuel system may be under pressure. Fuel
pressure will be released from fuel system. Remove hose, reinstall
protective cap, and fuel tank filler cap.
3) Wait 5 seconds. Use care when disconnecting fuel lines, as
some fuel pressure may still exist in fuel lines.
NOTE: One or more DTCs may set when fuel pump relay is removed.
Clear DTCs from PCM after fuel pressure release procedure. To
clear DTCs from PCM, see CLEARING DTCS under SELF-DIAGNOSTIC
SYSTEM in SELF-DIAGNOSTICS - JEEP, TRUCKS & RWD VANS
article.
Vehicles Without Fuel Rail Test Port
1) Remove gas cap. Using a non-metallic tool, open flapper
valve in filler neck to relieve pressure. Remove fuel pump relay from
Power Distribution Center (PDC). Relays are identified on label under
PDC cover. Start and run engine until it stalls. Attempt to start
engine. Continue restarting engine until it will no longer run. Turn
ignition off.
CAUTION: DO NOT supply power to fuel injector for more than 4 seconds,
or fuel injector may be damaged.
2) Disconnect any fuel injector connector. Connect a jumper
wire between either fuel injector terminal and positive battery
terminal. Connect another jumper wire to other fuel injector terminal.
Momentarily touch other end of jumper wire to negative battery
terminal.
3) Place a shop towel under fuel line quick-connector at fuel
rail. Use care when disconnecting fuel lines, as some fuel pressure
may still exist in fuel lines. Disconnect fuel line quick-connector.
Reinstall fuel pump relay in PDC. Clear DTCs from PCM. To clear DTCs
from PCM, see CLEARING DTCS under SELF-DIAGNOSTIC SYSTEM in SELF-
DIAGNOSTICS - JEEP, TRUCKS & RWD VANS article.
FUEL PRESSURE TEST

Connect a jumper wire between OPS connector terminals. Start engine
and allow to idle for 20 seconds. Increase engine speed to 1600 RPM.
If chime sounds, system is currently functioning properly. If chime
does not sound, go to next step.
4) Remove instrument cluster. See appropriate INSTRUMENT
PANELS article. Disconnect Instrument cluster 10-pin Gray connector
"B". Connect a jumper wire between ground and Dark Blue/Red wire of
instrument cluster 10-pin Gray connector terminal No. 7. Turn ignition
on. If chime sounds, replace instrument cluster. If chime does not
sound, repair open Dark Blue/Red wire.
CHIME INOPERATIVE - KEY IN IGNITION & LF DOOR OPEN
NOTE: For connector terminal identification and wiring diagrams,
see BODY CONTROL COMPUTER - INTRODUCTION article. Perform
VERIFICATION TEST VER-1A after each repair.
CAUTION: Always turn ignition switch to OFF position prior to
disconnecting any module connector.
1) Turn ignition off. Open driver's door. If chime does not
sound, go to next step. If chime sounds, system is currently
functioning correctly.
2) Using scan tool, read driver's door ajar switch status. If
scan tool displays LFDOOR AJAR SWITCH: CLOSED, go to next step. If
scan tool does not display LFDOOR AJAR SWITCH: CLOSED, go to OPEN LEFT
DOOR AJAR CIRCUIT.
3) Using scan tool, read key-in ignition chime state. If scan
tool does not display KEY-IN IGNITION CHIME STATE: ON, go to next
step. If scan tool displays KEY-IN IGNITION CHIME STATE: ON, replace
Central Timer Module (CTM). CTM is located under left side of
instrument panel.
4) Disconnect key-in ignition switch connector. See Fig. 1.
Connect jumper wire between key-in ignition switch connector Light
Blue wire and ground. Using scan tool, read key-in ignition chime
state. If scan tool does not display KEY-IN IGNITION CHIME STATE: ON,
go to next step. If scan tool displays KEY-IN IGNITION CHIME STATE:
ON, replace ignition switch. See appropriate STEERING COLUMN SWITCHES
article.
Fig. 1: Identifying Steering Column Harness Connector Locations
Courtesy of Chrysler Corp.
5) Access CTM 14-pin Green connector C1. Remove connector
cover. Do not disconnect connector. Connect a backprobe jumper wire

disconnecting any module connector.
1) Disconnect Oil Pressure Switch (OPS). OPS is located near\
bottom of distributor. Connect a jumper wire between OPS connector
terminals. Start engine and allow to idle for 20 seconds. Increase
engine speed to 1600 RPM. If chime sounds, go to next step. If chime
does not sound, go to step 3).
2) Turn ignition on. Using scan tool, actuate chime. If chime
does not sound, replace Central Timer Module (CTM). CTM is located
under left side of instrument panel. If chime sounds, system is
currently functioning properly.
3) Using scan tool, access CLUSTER MONITOR. With engine
running, read CCD oil pressure. If scan tool reading does not match
instrument cluster reading, replace instrument cluster. If scan tool
reading matches instrument cluster reading, go to next step.
4) Remove jumper wire. Connect a jumper wire between ground
and OPS connector Gray wire. Start engine and allow to idle for 20
seconds. Increase engine speed to 1600 RPM. If chime sounds, repair
open ground circuit between OPS connector and ground. If chime does
not sound, go to next step.
5) Turn ignition on. Using scan tool, actuate chime. If chime
does not sound, replace Central Timer Module (CTM). CTM is located
under left side of instrument panel. If chime sounds, go to next step.
6) Remove instrument cluster. See appropriate INSTRUMENT
PANELS article. Disconnect CTM 14-pin Green connector C1. Using an
external ohmmeter, measure resistance of Dark Blue/Red wire between
CTM 14-pin Green connector C1 terminal No. 2 and instrument cluster
10-pin connector C2 terminal No. 7. If resistance is less than 5 ohms,
replace CTM. If resistance is 5 ohms or more, repair open Dark
Blue/Red wire.
CHIME SOUNDS WITH DRIVER DOOR OPEN
NOTE: For connector terminal identification and wiring diagrams,
see BODY CONTROL COMPUTER - INTRODUCTION article. Perform
VERIFICATION TEST VER-1A after each repair.
CAUTION: Always turn ignition switch to OFF position prior to
disconnecting any module connector.
1) Ensure all interior and exterior lights are off. Remove
ignition key and open driver's door. If chime does not sound, system
is currently functioning correctly. If chime sounds, go to next step.
2) Using scan tool, read key-in ignition chime state. If scan
tool displays KEY-IN IGNITION CHIME STATE: "ON/OFF", go to next step.
If scan tool does not display KEY-IN IGNITION CHIME STATE: "ON/OFF",
replace Central Timer Module (CTM). CTM is located under left side of
instrument panel.
3) Disconnect key-in ignition switch connector. See Fig. 1.
Using scan tool, read key-in ignition chime state. If scan tool
displays KEY-IN IGNITION CHIME STATE: ON, go to next step. If scan
tool does not display KEY-IN IGNITION CHIME STATE: ON, replace
ignition switch. See appropriate STEERING COLUMN SWITCHES article.
4) Turn ignition off. Disconnect Central Timer Module (CTM).\
CTM is located under left side of instrument panel. Remove ignition
key. Ensure all lights and accessories are off. Close all doors. Using
external ohmmeter, measure resistance between ground and terminal No.
9 (Light Blue wire) on CTM Green connector "A". If resistance is less
than 10 ohms, repair Light Blue wire between CTM and ignition switch
for short to ground. If resistance is 10 ohms or more, replace CTM.
DOOR AJAR SYSTEM

operator's foot off accelerator pedal, S/C compensates for excessive
S/C cable slack. If lift foot sets are continually used, speed control
overshoot/undershoot condition will develop.
To "unlearn" overshoot/undershoot condition, operator must
press and release set button while maintaining desired speed with
accelerator pedal, then turn S/C switch to OFF position after waiting
10 seconds. This procedure must be repeated 10-15 times to completely
unlearn overshoot/undershoot condition.
COMPONENT TESTS
WARNING: Vehicle is equipped with an air bag. Air bag must be
deactivated before servicing speed control components on or
around steering column. See appropriate AIR BAG RESTRAINT
SYSTEMS article.
NOTE: For component locations, See COMPONENT LOCATIONS. For
connector terminal identification, see CONNECTOR
IDENTIFICATION. For wiring diagram, see WIRING DIAGRAMS.
BRAKE SWITCH
Disconnect brake switch 6-pin connector. Using an ohmmeter,
check for continuity at brake switch. See Fig. 1. If continuity is not
as specified in BRAKE SWITCH CONTINUITY table, check brake switch
adjustment. See BRAKE SWITCH under REMOVAL & INSTALLATION. If brake
switch adjustment is okay, replace defective brake switch.
BRAKE SWITCH CONTINUITY








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Switch Plunger  Check Between  Continuity 


Position  Terminals  










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Depressed  1 & 2  Yes 











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SPEED CONTROL SERVO
1) Start engine. Disconnect Speed Control (S/C) servo 4-pin
connector. Turn S/C on. Using a voltmeter, check voltage at S/C servo
connector terminal No. 3 (Dark Blue/Red wire). Battery voltage should
exist when brake pedal is not depressed. If battery voltage exists, go
to next step. If battery voltage does not exist, check circuit between
brake switch and S/C servo. See WIRING DIAGRAMS.
2) Connect a jumper wire between S/C servo pin No. 3 and S/C
servo connector terminal No. 3. Check voltage at S/C servo pins No. 1,
2 and 4. If battery voltage does not exist, replace S/C servo. If
battery voltage exists, go to next step.
3) Turn ignition off. Check for continuity between S/C servo
connector terminal No. 4 and ground. If continuity exists, test is
complete. If continuity does not exist, repair open ground circuit as
necessary.
VACUUM SUPPLY
Gasoline Engines
1) Disconnect vacuum hose at speed control servo. Install
vacuum gauge to disconnected vacuum hose. Start engine and observe

TROUBLE SHOOTING
NOTE: To trouble shoot mechanical engine components, see
appropriate table in TROUBLE SHOOTING article in GENERAL
INFORMATION.
REMOVAL & INSTALLATION
CAUTION: When battery is disconnected, vehicle computer and memory
systems may lose memory data. Driveability problems may exist
until computer systems have completed a relearn cycle. See
COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION
before disconnecting battery.
NOTE: For installation reference, label all electrical connectors,
vacuum hoses and fuel lines before removal. Also place mating
marks on engine hood and other major assemblies before
removal.
FUEL PRESSURE RELEASE
CAUTION: Fuel system is under pressure. Pressure must be released
before servicing fuel system components.
Gasoline
1) Disconnect negative battery cable. Loosen fuel tank cap to
release tank pressure. Press on filler tube flap to relieve any
additional tank pressure.
NOTE: Fuel filler tube has spring-loaded flap located below fuel
fill cap to serve as secondary seal if fuel fill cap is not
tightened. It is part of EVAP monitor system when vehicle is
equipped with leak detection pump (LDP). Vehicle may be
equipped with flap installed into fuel filler tube even if
vehicle is NOT equipped with LDP and EVAP monitor system.
2) Remove fuel pump relay from Power Distribution Center
(PDC). For location of relay, refer to label on underside of PDC
cover. Start and run engine until it stalls. Attempt restarting engine
until it will no longer run.
3) Unplug connector from an injector. Attach one end of a
jumper wire (18 gauge or smaller) with alligator clips to either
injector terminal. Connect other end of jumper wire to positive side
of battery. Connect one end of a second jumper wire to remaining
injector terminal.
WARNING: Powering an injector for more than a few seconds will
permanently damage injector.
4) Touch other end of second jumper wire to negative terminal
of battery for no more than a few seconds. Place a rag below fuel
line. Disconnect quick-connect fitting at fuel rail. See FUEL LINE
DISCONNECT FITTINGS. Return fuel pump relay to PDC.
Compressed Natural Gas Fuel Tube Purging (5.2L)
1) Close control valve (clockwise) on all fuel cylinders.
Open manual shutoff valve (open when handle is parallel to fuel
tubes).
2) Start and operate engine until it runs out of fuel.
Attempt 3 more engine starts. If check valve or fuel fill receptacle