NOTE: For additional information on fuel pressure and fuel pump
testing procedures, see appropriate NO TROUBLE CODE (NTC)
TEST and NO START (NS) TEST in SELF-DIAGNOSTICS - JEEP,
TRUCKS & RWD VANS article.
Vehicles With Fuel Rail Test Port
1) Disconnect negative battery cable. Release fuel pressure.
See FUEL PRESSURE RELEASE. Install fuel pressure gauge with hose on
fuel pressure test port.
2) Start engine and allow to idle. Fuel pressure should be
44-54 psi (3.1-3.8 kg/cm
). If no fuel pressure exists and engine will
not start, fuel pump relay and control circuit may be defective. See
FUEL PUMP RELAY.
3) If fuel pressure exceeds specification, fuel pump is okay,
but fuel pressure regulator is defective. Replace fuel pressure
regulator. Fuel pressure regulator is incorporated with the fuel
filter. Fuel filter/fuel pressure regulator is located on top of fuel
tank, in fuel pump module. See REMOVAL, OVERHAUL & INSTALLATION -
TRUCKS & RWD VANS - GASOLINE article.
Vehicles Without Fuel Rail Test Port
1) Disconnect negative battery cable. Release fuel pressure.
See FUEL PRESSURE RELEASE. Fuel pressure gauge is installed between
fuel supply line and fuel line fitting on fuel rail.
2) To disconnect fuel supply line from fuel rail, ensure area
around fuel supply line and fuel rail are clean. Note direction of
latch clip installation. Latch clip is located on top of fuel supply
line at fuel rail. See Fig. 1. Using 2 screwdrivers, pry latch clip
upward, and remove from fuel rail.
3) Pull fuel supply line from fuel rail. Install Adapter
(6923) into fuel rail. Ensure adapter is fully seated in fuel rail.
Install latch clip into fuel rail, with latch clip fingers pointing
downward. If latch clip will not fully seat so latch clip fingers
extend downward below fitting on fuel rail, adapter may not be fully
seated in fuel rail.
4) Connect fuel supply line to adapter. Ensure fuel supply
line fully seats in adapter. Remove protective cap from test port, and
install Fuel Pressure Gauge/Hose (5069) at test port.
5) Start engine and allow to idle. Fuel pressure should be
44-54 psi (3.1-3.8 kg/cm
). If no fuel pressure exists and engine will
not start, fuel pump relay and control circuit may be defective. See
FUEL PUMP RELAY.
6) If fuel pressure exceeds specification, fuel pump is okay,
but fuel pressure regulator is defective. Replace fuel pressure
regulator. Fuel pressure regulator is incorporated with the fuel
filter. Fuel filter/fuel pressure regulator is located on top of fuel
tank, in fuel pump module. See REMOVAL, OVERHAUL & INSTALLATION -
TRUCKS & RWD VANS - GASOLINE article.
7) On all models, release fuel pressure. See FUEL PRESSURE
RELEASE. Remove latch clip. Remove test equipment. Before reinstalling
fuel supply line, ensure fuel supply line fitting and fitting on fuel
rail are clean.
8) Lubricate fuel supply line fitting and fitting on fuel
rail with engine oil. Install fuel supply line on fuel rail.
9) Install latch clip into fuel rail, with latch clip fingers
pointing downward. Ensure latch clip is fully seated. Latch clip
fingers should extend downward below fitting on fuel rail when fully
seated.
10) Pull on fuel supply line to ensure fuel supply line is
fully locked on fuel rail. Reinstall negative battery cable. Start
engine and check for fuel leaks.
Fig. 1: Identifying Latch Clip & Installing Fuel Pressure Gauge
Courtesy of Chrysler Corp.
FUEL PUMP RELAY
On all models, if fuel pump relay or control circuit becomes
defective, a Diagnostic Trouble Code (FTC) may be stored in the PCM.
For additional information on diagnosis for fuel pump relay and
control circuit, see TEST TC-101A in SELF-DIAGNOSTICS - JEEP, TRUCKS &
RWD VANS article.
IGNITION CHECKS
NOTE: For ignition system spark testing and component testing, see
TEST NTC-2A in SELF-DIAGNOSTICS - JEEP, TRUCKS & RWD VANS
article.
NO-START TESTS
NO-START TESTING PROCEDURES
For no-start testing procedures, see TEST NS-1A in SELF-
DIAGNOSTICS - JEEP, TRUCKS & RWD VANS article.
IDLE SPEED & IGNITION TIMING
Idle speed and mixture are controlled by Powertrain Control
Module (PCM). No adjustment is required. PCM controls Idle Air Control\
(IAC) motor for proper idle speed. See TEST TC-25A in SELF-DIAGNOSTICS\
- JEEP, TRUCKS & RWD VANS article.
Ignition timing is controlled by PCM and is nonadjustable. If
vehicle is equipped with a distributor, DO NOT attempt to adjust
timing by rotating distributor. If distributor is rotated, fuel system
synchronization will be changed. If distributor is rotated or removed,
check fuel system synchronization. See FUEL SYSTEM SYNCHRONIZATION
under FUEL SYSTEM in ON-VEHICLE ADJUSTMENTS - TRUCKS & RWD VANS - CNG
& GASOLINE article.
SUMMARY
If no faults were found while performing basic diagnostic
procedures, proceed to SELF-DIAGNOSTICS - JEEP, TRUCKS & RWD VANS
article. If no diagnostic trouble codes are found in self-diagnostics,
proceed to TROUBLE SHOOTING - NO CODES - GASOLINE article for
diagnosis by symptom (i.e., ROUGH IDLE, NO-START, etc.) or
intermittent diagnostic procedures.
* ONE GAUGE NOT OPERATING PROPERLY
OVERHEAD CONSOLE CONCERNS
* AVERAGE MPH/FUEL ECON INOPERATIVE OR WRONG (CMTC FAILS TO
RESPOND TO INSTRUMENT CLUSTER DIMMING, DISTANCE TO EMPTY
INOPERATIVE OR WRONG, ELAPSED TIME INOPERATIVE/WRONG, SWITCH
ON CMTC INOPERATIVE, TRIP ODOMETER INOPERATIVE/WRONG)
* CMTC DISPLAY SHOWS FAILED
* CMTC SEGMENTS FAIL TO LIGHT UP
* INCORRECT READING BEYOND +/- 5
* REPAIRING "OC" IN CMTC DISPLAY
* REPAIRING "SC" IN CMTC DISPLAY
POWER DOOR LOCK SYSTEM
* DOOR LOCK SWITCH FAILURE (PDL)
* DOOR UNLOCK SWITCH FAILURE (PDL)
* AUTOMATIC (ROLLING) DOOR LOCKS INOPERATIVE
* DOORS LOCK WITH KEY IN IGNITION & LEFT DOOR OPEN
* ONE OR ALL DOORS FAILING TO LOCK FROM ONE SWITCH (ONE OR ALL
DOORS FAILING TO UNLOCK FROM ONE SWITCH)
* REMOTE KEYLESS ENTRY PROBLEM
VEHICLE THEFT/SECURITY SYSTEM
* DOOR DISARM SWITCH FAILURE
* DOOR LOCK SWITCH FAILURE
* DOOR UNLOCK SWITCH FAILURE
* EEPROM CHECKSUM FAILURE
* INTERNAL ROM TEST FAILURE
* IDENTIFYING VTSS PROBLEMS
WINDSHIELD WIPER SYSTEM
* WIPER PARK SWITCH FAILURE
* INTERMITTENT WIPERS INOPERATIVE
* NO WIPER ACTUATION AFTER WASH BUTTON PUSHED
* WIPER SPEED SENSITIVE FEATURE INOPERATIVE
CHIME SYSTEM
CHIME INOPERATIVE WITH EXTREME COOLANT TEMPERATURE
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) Using scan tool, actuate chime. If chime sounds, go to
next step. If chime does not sound, replace Central Timer Module
(CTM). CTM is located under left side of instrument panel.
2) Using scan tool, read Powertrain Control Module (PCM)
DTCs. If no engine coolant temperature related codes exist, go to next
step. If engine coolant temperature related codes exist, see
appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE section.
3) Due to difficult access of coolant temperature sensor, Oil
Pressure Switch (OPS) will be used to verify CCD bus message from PCM.\
Disconnect OPS connector. OPS is located near bottom of distributor.
circuit.
ONE GAUGE NOT OPERATING PROPERLY
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 or connecting any module connector.
1) Push and hold RESET button while cycling ignition key; ON-
OFF-ON. Instrument cluster self-test will start. If inoperative gauge
reached proper calibration point, go to next step. If inoperative
gauge did not reach proper calibration point, replace instrument
cluster.
2) Stop instrument cluster self-test. If problem is with
speedometer, go to next step. If problem is with oil pressure gauge,
go to step 5). If problem is with temperature gauge, go to step 14).
If problem is with fuel level gauge, go to appropriate SELF-
DIAGNOSTICS article in ENGINE PERFORMANCE section and review
powertrain symptoms. If problem is with volt gauge, go to step 16). If
problem is with tachometer, go to step 18).
3) Using scan tool, select BODY, SYSTEMS TESTS then PCM
MONITOR. If scan tool displays PCM ACTIVE ON BUS, go to next step. If
scan tool does not display PCM ACTIVE ON BUS, go to appropriate
VEHICLE COMMUNICATIONS article.
4) Raise and support all wheels. Start engine and place gear
selector in drive. Using scan tool, select MIC, MONITORS then CCD BUS
ENGINE INFO. Read VSS. If vehicle speed on scan tool matches
speedometer, see appropriate ANTI-LOCK BRAKE article. If vehicle speed
on scan tool does not match speedometer, replace instrument cluster
circuit board.
5) Turn ignition on. If CHECK GAUGES light illuminated, go to
next step. If CHECK GAUGES light did not illuminate, go to step 11).
6) Turn ignition off. Inspect oil level. If oil level is
within specification, go to next step. If oil level is not within
specification, adjust oil level and retest.
7) Turn ignition on. Disconnect engine Oil Pressure Switch
(OPS) connector. OPS is located near bottom of distributor. If CHECK
GAUGES light went out, go to next step. If CHECK GAUGES light did not
go out, go to step 10).
8) Remove OPS. Connect mechanical oil pressure gauge to OPS
port. Start engine. If engine oil pressure at idle is 4 psi or more,
go to next step. If engine oil pressure at idle is less than 4 psi,
repair mechanical engine problem.
9) Run engine to reach normal operating temperature. If
engine oil pressure at idle is 4 psi or more, replace OPS. If engine
oil pressure at idle is less than 4 psi, repair mechanical engine
problem.
10) Turn ignition off. Disconnect PCM White connector C2. PCM
is located in engine compartment on right inner fender. Using an
external ohmmeter, measure resistance between ground and PCM Black
connector terminal No. 23 (Gray/Orange wire). If resistance is less
than 5 ohms, repair short to ground in Gray/Orange wire. If resistance
is 5 ohms or more, replace PCM.
11) Disconnect engine Oil Pressure Switch (OPS) connector.
OPS is located near bottom of distributor. Using an external ohmmeter,
measure resistance between ground and OPS connector Black/Light Blue
wire. If resistance is less than 5 ohms, go to next step. If
resistance is 5 ohms or more, repair open Black/Light Blue wire.
Black/Light Blue wire is a common sensor ground. If no other engine
sensors are failed, repair ground between sensor and splice. If
multiple engine sensors have failed, repair ground between splice and
PCM.
12) Connect jumper wire between OPS connector terminals. If
oil pressure warning indicator illuminates, replace OPS. If oil
pressure warning indicator does not illuminate, go to next step.
13) Do not remove jumper wire. Disconnect PCM Black connector
C2. PCM is located in engine compartment on right inner fender. Using
an external ohmmeter, measure resistance between ground and PCM White
connector C2 terminal No. 23 (Gray/Orange wire). If resistance is less\
than 5 ohms, replace PCM. If resistance is 5 ohms or more, repair open
Gray/Orange wire.
14) Check cooling system operation. If cooling system is
operating properly, go to next step. If cooling system is not
operating properly, repair engine cooling problem.
15) Using scan tool, select PCM MONITOR under SYSTEM TESTS.
If scan tool displays PCM ACTIVE ON BUS, system is currently
functioning properly. If scan tool does not display PCM ACTIVE ON BUS,
go to appropriate VEHICLE COMMUNICATIONS article.
16) Using scan tool, select MODULE ENGINE CONTROLLER. Read
PCM DTCs. If scan tool displays any charging system related DTCs, go
to appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE section
and repair DTC as necessary. If scan tool does not display any
charging system related DTCs, go to next step.
17) Check charging system operation. If charging system is
operating properly, replace instrument cluster. If charging system is
not operating properly, repair engine charging problem.
18) Using scan tool, select BODY COMPUTER MONITORS. Read CCD
BUS ENGINE INFO. If scan tool displays engine RPM, replace instrument
cluster. If scan tool does not display engine RPM, replace PCM.
OVERHEAD CONSOLE CONCERNS
AVERAGE MPH/FUEL ECON INOPERATIVE OR WRONG (CMTC FAILS TO
RESPOND TO INSTRUMENT CLUSTER DIMMING, DISTANCE TO EMPTY
INOPERATIVE OR WRONG, ELAPSED TIME INOPERATIVE/WRONG, SWITCH
ON CMTC INOPERATIVE, TRIP ODOMETER INOPERATIVE/WRONG)
NOTE: If any listed symptoms exist, Compass Mini-Trip computer
(CMTC) is defective. Replace CMTC. Perform VERIFICATION TEST
VER- 1A after each repair.
CMTC SHOWS FAILED
NOTE: For connector terminal identification and wiring diagrams,
see BODY CONTROL COMPUTER - INTRODUCTION article. Perform
VERIFICATION TEST VER-1A after each repair.
Using scan tool, perform AUTO SELF TEST. If CMTC shows
failed, replace CMTC. If CMTC does not show failed, system is
currently functioning properly.
CMTC SEGMENTS FAIL TO LIGHT UP
NOTE: For connector terminal identification and wiring diagrams,
see BODY CONTROL COMPUTER - INTRODUCTION article. Perform
VERIFICATION TEST VER-1A after each repair.
Using scan tool, perform AUTO SELF TEST. If CMTC segments
fail to illuminate, replace CMTC. If CMTC segments all illuminate
properly, system is currently functioning properly.
INCORRECT READING BEYOND +/- 5