DIAGNOSIS AND TESTING - VEHICLE THEFT
SECURITY SYSTEM
The Vehicle Theft Security System (VTSS) is
divided into two basic subsystems: Vehicle Theft
Alarm (VTA) and Sentry Key Immobilizer System
(SKIS). Following are the recommended procedures
for diagnosis and testing of each of these two sub-
systems.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, SEAT BELT TENSIONER,
FRONT IMPACT SENSORS, SIDE CURTAIN AIRBAG,
OR INSTRUMENT PANEL COMPONENT DIAGNOSIS
OR SERVICE. DISCONNECT AND ISOLATE THE
BATTERY NEGATIVE (GROUND) CABLE, THEN
WAIT TWO MINUTES FOR THE SYSTEM CAPACI-
TOR TO DISCHARGE BEFORE PERFORMING FUR-
THER DIAGNOSIS OR SERVICE. THIS IS THE ONLY
SURE WAY TO DISABLE THE SUPPLEMENTAL
RESTRAINT SYSTEM. FAILURE TO TAKE THE
PROPER PRECAUTIONS COULD RESULT IN ACCI-
DENTAL AIRBAG DEPLOYMENT AND POSSIBLE
PERSONAL INJURY.
VEHICLE THEFT ALARM
Models equipped with the Rest-Of-World (ROW)
premium version of the Vehicle Theft Alarm (VTA)
provide some preliminary diagnostic feedback by illu-minating the security indicator located in the Elec-
troMechanical Instrument Cluster (EMIC). If the
security indicator illuminates with the ignition
switch in the On position, it indicates that there is a
communication problem between the Intrusion
Transceiver Module (ITM) and the Body Control
Module (BCM), or between the ITM and the siren
module. The BCM will also turn on the security indi-
cator if it receives a message from the ITM indicating
that the ITM has stored a Diagnostic Trouble Code
(DTC) for a siren module fault.
The hard wired circuits and components of the
VTA may be diagnosed and tested using conventional
diagnostic tools and procedures. However, conven-
tional diagnostic methods may not prove conclusive
in the diagnosis of the Body Control Module (BCM),
the ElectroMechanical Instrument Cluster (EMIC),
the Intrusion Transceiver Module (ITM), or the Pro-
grammable Communications Interface (PCI) data bus
network. The most reliable, efficient, and accurate
means to diagnose the BCM, the EMIC, the ITM,
and the PCI data bus network inputs and outputs
related to the VTA requires the use of a DRBIIIt
scan tool. Refer to the appropriate diagnostic infor-
mation.
Refer to the appropriate wiring information. The
wiring information includes wiring diagrams, proper
wire and connector repair procedures, further details
on wire harness routing and retention, as well as
pin-out and location views for the various wire har-
ness connectors, splices and grounds.
8Q - 6 VEHICLE THEFT SECURITYKJ
VEHICLE THEFT SECURITY (Continued)
cycles that occur after the front Wash switch state
changes to open, and to determine the proper inter-
val at which to de-energize the wiper on/off relay to
complete the wipe-after-wash mode cycle.
DIAGNOSIS AND TESTING - FRONT WIPER &
WASHER SYSTEM
FRONT WIPER SYSTEM
If the front wiper motor operates, but the wipers
do not move on the windshield, replace the faulty
front wiper module. If the wipers operate, but chat-
ter, lift, or do not clear the glass, clean and inspect
the front wiper system components as required.
(Refer to 8 - ELECTRICAL/FRONT WIPERS/WASH-
ERS - INSPECTION) and (Refer to 8 - ELECTRI-
CAL/FRONT WIPERS/WASHERS - CLEANING). For
diagnosis and testing of the multi-function switch
(Refer to 8 - ELECTRICAL/LAMPS/LIGHTING -
EXTERIOR/MULTI-FUNCTION SWITCH - DIAG-
NOSIS AND TESTING). Refer to the appropriate
wiring information. The wiring information includes
wiring diagrams, proper wire and connector repair
procedures, details of wire harness routing and
retention, connector pin-out information and location
views for the various wire harness connectors, splices
and grounds.
The hard wired circuits and components of the
front wiper and washer system may be diagnosed
and tested using conventional diagnostic tools and
procedures. However, conventional diagnostic meth-
ods may not prove conclusive in the diagnosis of the
Body Control Module (BCM), or the inputs to or out-
puts from the BCM that control the various front
wiper and washer system operating modes. The most
reliable, efficient, and accurate means to diagnose
the BCM, or the BCM inputs and outputs related to
the various front wiper and washer system operating
modes requires the use of a DRBIIItscan tool. Refer
to the appropriate diagnostic information.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, SEAT BELT TENSIONER,
SIDE CURTAIN AIRBAG, OR INSTRUMENT PANEL
COMPONENT DIAGNOSIS OR SERVICE. DISCON-
NECT AND ISOLATE THE BATTERY NEGATIVE
(GROUND) CABLE, THEN WAIT TWO MINUTES FOR
THE SYSTEM CAPACITOR TO DISCHARGE BEFORE
PERFORMING FURTHER DIAGNOSIS OR SERVICE.
THIS IS THE ONLY SURE WAY TO DISABLE THE
SUPPLEMENTAL RESTRAINT SYSTEM. FAILURE TO
TAKE THE PROPER PRECAUTIONS COULDRESULT IN ACCIDENTAL AIRBAG DEPLOYMENT
AND POSSIBLE PERSONAL INJURY.
FRONT WASHER SYSTEM
The diagnosis found here addresses an electrically
inoperative front washer system. If the washer
pump/motor operates, but no washer fluid is emitted
from the front washer nozzles, be certain to check
the fluid level in the reservoir. Also inspect the front
washer system components as required. (Refer to 8 -
ELECTRICAL/FRONT WIPERS/WASHERS -
INSPECTION). Refer to the appropriate wiring infor-
mation. The wiring information includes wiring dia-
grams, proper wire and connector repair procedures,
details of wire harness routing and retention, connec-
tor pin-out information and location views for the
various wire harness connectors, splices and grounds.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, SEAT BELT TENSIONER,
SIDE CURTAIN AIRBAG, OR INSTRUMENT PANEL
COMPONENT DIAGNOSIS OR SERVICE. DISCON-
NECT AND ISOLATE THE BATTERY NEGATIVE
(GROUND) CABLE, THEN WAIT TWO MINUTES FOR
THE SYSTEM CAPACITOR TO DISCHARGE BEFORE
PERFORMING FURTHER DIAGNOSIS OR SERVICE.
THIS IS THE ONLY SURE WAY TO DISABLE THE
SUPPLEMENTAL RESTRAINT SYSTEM. FAILURE TO
TAKE THE PROPER PRECAUTIONS COULD
RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT
AND POSSIBLE PERSONAL INJURY.
(1) Turn the ignition switch to the On position.
Turn the control knob on the right (wiper) control
stalk of the multi-function switch to the On position.
Check whether the front wiper system is operating.
If OK, go to Step 2. If not OK, test and repair the
front wiper system before continuing with these
tests. Refer to FRONT WIPER SYSTEM .
(2) Turn the control ring on the right (wiper) con-
trol stalk of the multi-function switch to the rear
Wash position. Check whether the rear washer sys-
tem is operating. If OK, test the multi-function
switch. (Refer to 8 - ELECTRICAL/LAMPS/LIGHT-
ING - EXTERIOR/MULTI-FUNCTION SWITCH -
DIAGNOSIS AND TESTING). If the multi-function
switch tests OK, go to Step 3. If the multi-function
switch does not test OK, replace the faulty switch.
(3) Turn the ignition switch to the Off position.
Disconnect and isolate the battery negative cable.
Disconnect the headlamp and dash wire harness con-
nector for the washer pump/motor unit from the
pump/motor unit connector receptacle. Check for con-
tinuity between the washer pump driver circuit cav-
8R - 6 FRONT WIPERS/WASHERSKJ
FRONT WIPERS/WASHERS (Continued)
mation includes wiring diagrams, proper wire and
connector repair procedures, details of wire harness
routing and retention, connector pin-out information
and location views for the various wire harness con-
nectors, splices and grounds.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, SEAT BELT TENSIONER,
SIDE CURTAIN AIRBAG, OR INSTRUMENT PANEL
COMPONENT DIAGNOSIS OR SERVICE. DISCON-
NECT AND ISOLATE THE BATTERY NEGATIVE
(GROUND) CABLE, THEN WAIT TWO MINUTES FOR
THE SYSTEM CAPACITOR TO DISCHARGE BEFORE
PERFORMING FURTHER DIAGNOSIS OR SERVICE.
THIS IS THE ONLY SURE WAY TO DISABLE THE
SUPPLEMENTAL RESTRAINT SYSTEM. FAILURE TO
TAKE THE PROPER PRECAUTIONS COULD
RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT
AND POSSIBLE PERSONAL INJURY.
(1) Check that the interior lighting switch on the
left (lighting) control stalk of the multi-function
switch is not in the dome lamp disable position. With
all four doors and the tailgate closed, open the rear
flip-up glass. The interior lamps should light. Close
the rear flip-up glass. Note whether the interior
lamps remain lighted. They should turn off after
about thirty seconds. If OK, go to Step 2. If not OK,
go to Step 9.
(2) Check the fused B(+) fuse (Fuse 17 - 15
ampere) in the Junction Block (JB). If OK, go to Step
3. If not OK, repair the shorted circuit or component
as required and replace the faulty fuse.
(3) Check for battery voltage at the fused B(+) fuse
(Fuse 17 - 15 ampere) in the JB. If OK, go to Step 4.
If not OK, repair the open fused B(+) circuit between
the JB and the Power Distribution Center (PDC) as
required.
(4) Check the fused ignition switch output (run-
acc) fuse (Fuse 22 - 10 ampere) in the JB. If OK, go
to Step 5. If not OK, repair the shorted circuit or
component as required and replace the faulty fuse.
(5) Turn the ignition switch to the On position.
Check for battery voltage at the fused ignition switch
output (run-acc) fuse (Fuse 22 - 10 ampere) in the
JB. If OK, turn the ignition switch to the Off position
and go to Step 6. If not OK, repair the open fused
ignition switch output (run-acc) circuit between the
JB and the ignition switch as required.
(6) Disconnect and isolate the battery negative
cable. Disconnect the instrument panel wire harness
connector for the multi-function switch (Connector
C-2) from the switch connector receptacle. Reconnect
the battery negative cable. Turn the ignition switchto the On position. Check for battery voltage at the
fused ignition switch output (run-acc) circuit cavity of
the instrument panel wire harness connector for the
multi-function switch (Connector C-2). If OK, go to
Step 7. If not OK, repair the open fused ignition
switch output (run-acc) circuit between the multi-
function switch and the JB as required.
(7) Turn the ignition switch to the Off position.
Disconnect and isolate the battery negative cable.
Test the multi-function switch. (Refer to 8 - ELEC-
TRICAL/LAMPS/LIGHTING - EXTERIOR/MULTI-
FUNCTION SWITCH - DIAGNOSIS AND
TESTING). If the multi-function switch tests OK,
reconnect the instrument panel wire harness connec-
tors for the multi-function switch to the switch con-
nector receptacles and go to Step 8. If the multi-
function switch does not test OK, replace the faulty
switch.
(8) Remove the tailgate inner trim panel. Discon-
nect the tailgate wire harness connector for the rear
wiper module from the module connector receptacle.
Check for continuity between the ground circuit cav-
ity of the tailgate wire harness connector for the rear
wiper module and a good ground. There should be
continuity. If OK, go to Step 9. If not OK, repair the
open ground circuit to ground (G312) as required.
(9) Check for continuity between the flip-up glass
ajar switch sense circuit cavity of the tailgate wire
harness connector for the rear wiper module and a
good ground. There should be continuity with the
rear flip-up glass open, and no continuity with the
rear flip-up glass closed. If OK, go to Step 10. If not
OK, repair the open flip-up glass ajar circuit between
the rear wiper module and the flip-up glass ajar
switch as required.
(10) Reconnect the battery negative cable. Check
for battery voltage at the fused B(+) circuit cavity of
the tailgate wire harness connector for the rear wiper
module. If OK, go to Step 11. If not OK, repair the
open fused B(+) circuit between the rear wiper mod-
ule and the JB as required.
(11) Turn the ignition switch to the On position.
Turn the control ring on the right (wiper) control
stalk of the multi-function switch to the Delay posi-
tion. Check for battery voltage at the rear wiper
intermittent driver circuit cavity of the tailgate wire
harness connector for the rear wiper module. If OK,
go to Step 12. If not OK, repair the open rear wiper
intermittent driver circuit between the rear wiper
module and the multi-function switch as required.
(12) Turn the control ring on the right (wiper) con-
trol stalk of the multi-function switch to the On posi-
tion. Check for battery voltage at the rear wiper on
driver circuit cavity of the tailgate wire harness con-
nector for the rear wiper module. If OK, replace the
faulty rear wiper module. If not OK, repair the open
KJREAR WIPERS/WASHERS 8R - 31
REAR WIPERS/WASHERS (Continued)
rear wiper on driver circuit between the rear wiper
module and the multi-function switch as required.
REAR WASHER SYSTEM
The diagnosis found here addresses an electrically
inoperative rear washer system. If the washer pump/
motor operates, but no washer fluid is emitted from
the rear washer nozzle, be certain to check the fluid
level in the reservoir. Also inspect the rear washer
system components as required. (Refer to 8 - ELEC-
TRICAL/REAR WIPERS/WASHERS - INSPECTION).
Refer to the appropriate wiring information. The wir-
ing information includes wiring diagrams, proper
wire and connector repair procedures, details of wire
harness routing and retention, connector pin-out
information and location views for the various wire
harness connectors, splices and grounds.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, SEAT BELT TENSIONER,
SIDE CURTAIN AIRBAG, OR INSTRUMENT PANEL
COMPONENT DIAGNOSIS OR SERVICE. DISCON-
NECT AND ISOLATE THE BATTERY NEGATIVE
(GROUND) CABLE, THEN WAIT TWO MINUTES FOR
THE SYSTEM CAPACITOR TO DISCHARGE BEFORE
PERFORMING FURTHER DIAGNOSIS OR SERVICE.
THIS IS THE ONLY SURE WAY TO DISABLE THE
SUPPLEMENTAL RESTRAINT SYSTEM. FAILURE TO
TAKE THE PROPER PRECAUTIONS COULD
RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT
AND POSSIBLE PERSONAL INJURY.
(1) Turn the ignition switch to the On position.
Turn the control ring on the right (wiper) control
stalk of the multi-function switch to the On position.
Check whether the rear wiper system is operating. If
OK, go to Step 2. If not OK, test and repair the rear
wiper system before continuing with these tests.
Refer to REAR WIPER SYSTEM .
(2) Pull the right (wiper) control stalk of the multi-
function switch toward the steering wheel. Check
whether the front washer system is operating. If OK,
test the multi-function switch. (Refer to 8 - ELEC-
TRICAL/LAMPS/LIGHTING - EXTERIOR/MULTI-
FUNCTION SWITCH - DIAGNOSIS AND
TESTING). If the multi-function switch tests OK, go
to Step 3. If the multi-function switch does not test
OK, replace the faulty switch.
(3) Turn the ignition switch to the Off position.
Disconnect and isolate the battery negative cable.
Disconnect the headlamp and dash wire harness con-
nector for the washer pump/motor unit from the
pump/motor unit connector receptacle. Check for con-
tinuity between the washer pump driver circuit cav-ity of the headlamp and dash wire harness connector
for the washer pump/motor unit and a good ground.
There should be no continuity. If OK, go to Step 4. If
not OK, repair the shorted washer pump driver cir-
cuit between the washer pump/motor unit and the
multi-function switch as required.
(4) Check for continuity between the washer pump
driver circuit cavities of the headlamp and dash wire
harness connector for the washer pump/motor unit
and the instrument panel wire harness connector for
the multi-function switch (Connector C-2). There
should be continuity. If OK, go to Step 5. If not OK,
repair the open washer pump driver circuit between
the washer pump/motor unit and the multi-function
switch as required.
(5) Check for continuity between the washer pump
sense circuit cavity of the headlamp and dash wire
harness connector for the washer pump/motor unit
and a good ground. There should be no continuity. If
OK, go to Step 6. If not OK, repair the shorted
washer pump sense circuit between the washer
pump/motor unit and the multi-function switch as
required.
(6) Check for continuity between the washer pump
sense circuit cavities of the headlamp and dash wire
harness connector for the washer pump/motor unit
and the instrument panel wire harness connector for
the multi-function switch (Connector C-2). There
should be continuity. If OK, replace the faulty washer
pump/motor unit. If not OK, repair the open washer
pump sense circuit between the washer pump/motor
unit and the multi-function switch as required.
CLEANING - REAR WIPER & WASHER SYSTEM
REAR WIPER SYSTEM
The squeegee of a wiper blade exposed to the ele-
ments for a long time tends to lose its wiping effec-
tiveness. Periodic cleaning of the squeegee is
suggested to remove any deposits of salt or road film.
The wiper blade, arm, and rear flip-up glass should
only be cleaned using a sponge or soft cloth and
windshield washer fluid, a mild detergent, or a non-
abrasive cleaner. If the wiper blade continues to
leave streaks, smears, hazing, or beading on the
glass after thorough cleaning of the squeegees and
the glass, the entire wiper blade assembly must be
replaced.
CAUTION: Protect the rubber squeegee of the wiper
blade from any petroleum-based cleaners, solvents,
or contaminants. These products can rapidly deteri-
orate the rubber squeegee.
8R - 32 REAR WIPERS/WASHERSKJ
REAR WIPERS/WASHERS (Continued)
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - ENGINE
DIAGNOSIS - INTRODUCTION
Engine diagnosis is helpful in determining the
causes of malfunctions not detected and remedied by
routine maintenance.
These malfunctions may be classified as either per-
formance (e.g., engine idles rough and stalls) or
mechanical (e.g., a strange noise).
(Refer to 9 - ENGINE - DIAGNOSIS AND TEST-
ING)ÐPERFORMANCE and (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)ÐMECHANICAL for
possible causes and corrections of malfunctions.
(Refer to 14 - FUEL SYSTEM/FUEL DELIVERY -
DIAGNOSIS AND TESTING) and (Refer to 14 -
FUEL SYSTEM/FUEL INJECTION - DIAGNOSIS
AND TESTING) for the fuel system diagnosis.Additional tests and diagnostic procedures may be
necessary for specific engine malfunctions that can
not be isolated with the Service Diagnosis charts.
Information concerning additional tests and diagno-
sis is provided within the following diagnosis:
²Cylinder Compression Pressure Test (Refer to 9 -
ENGINE - DIAGNOSIS AND TESTING).
²Cylinder Combustion Pressure Leakage Test
(Refer to 9 - ENGINE - DIAGNOSIS AND TEST-
ING).
²Engine Cylinder Head Gasket Failure Diagnosis
(Refer to 9 - ENGINE/CYLINDER HEAD - DIAGNO-
SIS AND TESTING).
²Intake Manifold Leakage Diagnosis (Refer to 9 -
ENGINE/MANIFOLDS/INTAKE MANIFOLD -
DIAGNOSIS AND TESTING).
DIAGNOSIS AND TESTING - ENGINE DIAGNOSIS - PERFORMANCE
CONDITION POSSIBLE CAUSE CORRECTION
ENGINE WILL NOT START 1. Weak battery 1. Charge or replace as necessary.
2. Corroded or loose battery
connections.2. Clean and tighten battery
connections. Apply a coat of light
mineral grease to the terminals.
3. Faulty starter. 3. (Refer to 8 - ELECTRICAL/
STARTING - DIAGNOSIS AND
TESTING).
4. Faulty coil or control unit. 4. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/IGNITION
COIL - REMOVAL).
5. Incorrect spark plug gap. 5. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/SPARK PLUG
- CLEANING).
6. Incorrect right bank cam timing. 6. Refer to engine timing in this
section.
7. Dirt or water in fuel system. 7. Clean system and replace fuel
filter.
8.Faulty fuel pump, relay or wiring. 8.Repair or replace as necessary.
9. Faulty cam or crank sensor 9. Refer to Ignition system.
ENGINE STALLS OR ROUGH IDLE 1. Vacuum leak. 1. Inspect intake manifold and
vacuum hoses, repair or replace as
necessary.
2. Faulty crank position sensor 2. Replace crank position sensor.
4. Faulty coil. 4. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/IGNITION
COIL - REMOVAL).
9 - 4 ENGINE - 3.7LKJ
ENGINE - 3.7L (Continued)
VISUAL TEST METHOD
With the engine cool, remove the coolant pressure
cap. Start the engine and allow it to warm up until
thermostat opens.
If a large combustion/compression pressure leak
exists, bubbles will be visible in the coolant.
COOLING SYSTEM TESTER METHOD
WARNING: WITH COOLING SYSTEM TESTER IN
PLACE, PRESSURE WILL BUILD UP FAST. EXCES-
SIVE PRESSURE BUILT UP, BY CONTINUOUS
ENGINE OPERATION, MUST BE RELEASED TO A
SAFE PRESSURE POINT. NEVER PERMIT PRES-
SURE TO EXCEED 138 kPa (20 psi).
Install Cooling System Tester 7700 or equivalent to
pressure cap neck. Start the engine and observe the
tester's pressure gauge. If gauge pulsates with every
power stroke of a cylinder a combustion pressure
leak is evident.
CHEMICAL TEST METHOD
Combustion leaks into the cooling system can also
be checked by using Bloc-Chek Kit C-3685-A or
equivalent. Perform test following the procedures
supplied with the tool kit.
REMOVAL
(1) Disconnect battery negative cable.
(2) Raise the vehicle on a hoist.
(3) Disconnect the exhaust pipe at the right side
exhaust manifold.
(4) Drain the engine coolant. Refer to COOLING
SYSTEM.
(5) Lower the vehicle.
(6) Remove the intake manifold. Refer to proce-
dure.
(7) Remove the cylinder head cover. Refer to proce-
dure.
(8) Remove the fan shroud. Refer to COOLING
SYSTEM.
(9) Remove oil fill housing from cylinder head.
(10) Remove accessory drive belt. Refer to COOL-
ING SYSTEM.
(11) Rotate the crankshaft until the damper timing
mark is aligned with TDC indicator mark.
(12) Verify the V6 mark on the camshaft sprocket
is at the 12 o'clock position. Rotate the crankshaft
one turn if necessary.
(13) Remove the crankshaft damper. Refer to pro-
cedure.
(14) Remove the timing chain cover. Refer to pro-
cedure.
(15) Lock the secondary timing chains to the idler
sprocket using Special Tool 8429 Timing Chain Hold-
ing Fixture.NOTE: Mark the secondary timing chain prior to
removal to aid in installation.
(16) Mark the secondary timing chain, one link on
each side of the V6 mark on the camshaft drive gear.
(17) Remove the right side secondary chain ten-
sioner. Refer to Timing Chain and Sprockets in this
section.
(18) Remove the cylinder head access plug.
(19) Remove the right side secondary chain guide.
Refer to Timing Chain and Sprockets in this section.
CAUTION: The nut on the right side camshaft
sprocket should not be removed for any reason, as
the sprocket and camshaft sensor target wheel is
serviced as an assembly. If the nut was removed
retorque nut to 5 N´m (44 in. lbs.).
(20) Remove the retaining bolt and the camshaft
drive gear.
CAUTION: Do not allow the engine to rotate. severe
damage to the valve train can occur.
CAUTION: Do not overlook the four smaller bolts at
the front of the cylinder head. Do not attempt to
remove the cylinder head without removing these
four bolts.
CAUTION: Do not hold or pry on the camshaft tar-
get wheel for any reason. A damaged target wheel
can result in a vehicle no start condition.
NOTE: The cylinder head is attached to the cylinder
block with twelve bolts.
(21) Remove the cylinder head retaining bolts.
(22) Remove the cylinder head and gasket. Discard
the gasket.
CAUTION: Do not lay the cylinder head on its gas-
ket sealing surface, do to the design of the cylinder
head gasket any distortion to the cylinder head
sealing surface may prevent the gasket from prop-
erly sealing resulting in leaks.
CLEANING
To ensure engine gasket sealing, proper surface
preparation must be performed, especially with the
use of aluminum engine components (Fig. 22). (Refer
to 9 - ENGINE - STANDARD PROCEDURE)
KJENGINE - 3.7L 9 - 31
CYLINDER HEAD - RIGHT (Continued)
(1) Position the engine exhaust manifold and gas-
ket on the two studs located on the cylinder head.
Install conical washers and nuts on these studs.
(2) Install remaining conical washers. Starting at
the center arm and working outward, tighten the
bolts and nuts to 25 N´m (18 ft. lbs.) torque.
(3) Install the exhaust heat shields.
(4) Raise and support the vehicle.
CAUTION: Over tightening heat shield fasteners,
may cause shield to distort and/or crack.
(5) Assemble exhaust pipe to manifold and secure
with bolts, nuts and retainers. Tighten the bolts and
nuts to 34 N´m (25 ft. lbs.) torque.
LEFT EXHAUST MANIFOLD
CAUTION: If the studs came out with the nuts when
removing the engine exhaust manifold, install new
studs. Apply sealer on the coarse thread ends.
Water leaks may develop at the studs if this precau-
tion is not taken.
(1) Position the engine exhaust manifold and gas-
ket on the two studs located on the cylinder head.
Install conical washers and nuts on these studs.
(2) Install remaining conical washers. Starting at
the center arm and working outward, tighten the
bolts and nuts to 25 N´m (18 ft. lbs.) torque.
(3) Install the exhaust heat shields.
(4) Raise and support the vehicle.
CAUTION: Over tightening heat shield fasteners,
may cause shield to distort and/or crack.
(5) Assemble exhaust pipe to manifold and secure
with bolts, nuts and retainers. Tighten the bolts and
nuts to 34 N´m (25 ft. lbs.) torque.
VALVE TIMING
DESCRIPTION
The timing drive system has been designed to pro-
vide quiet performance and reliability to support a
non-free wheelingengine. Specifically the intake
valves are non-free wheeling and can be easily dam-
aged with forceful engine rotation if camshaft-to-
crankshaft timing is incorrect. The timing drive
system consists of a primary chain, two secondary
timing chain drives and a counterbalance shaft drive.
OPERATION
The primary timing chain is a single inverted tooth
chain type. The primary chain drives the large 40
tooth idler sprocket directly from a 20 tooth crank-shaft sprocket. Primary chain motion is controlled by
a pivoting leaf spring tensioner arm and a fixed
guide. The arm and the guide both use nylon plastic
wear faces for low friction and long wear. The pri-
mary chain receives oil splash lubrication from the
secondary chain drive and designed oil pump leak-
age. The idler sprocket assembly connects the pri-
mary chain drive, secondary chain drives, and the
counterbalance shaft. The idler sprocket assembly
consists of two integral 26 tooth sprockets a 40 tooth
sprocket and a helical gear that is press-fit to the
assembly. The spline joint for the 40 tooth sprocket is
a non ± serviceable press fit anti rattle type. A spiral
ring is installed on the outboard side of the fifty
tooth sprocket to prevent spline disengagement. The
idler sprocket assembly spins on a stationary idler
shaft. The idler shaft is a light press-fit into the cyl-
inder block. A large washer on the idler shaft bolt
and the rear flange of the idler shaft are used to con-
trol sprocket thrust movement. Pressurized oil is
routed through the center of the idler shaft to pro-
vide lubrication for the two bushings used in the
idler sprocket assembly.
There are two secondary drive chains, both are
roller type, one to drive the camshaft in each SOHC
cylinder head. There are no shaft speed changes in
the secondary chain drive system. Each secondary
chain drives a 26 tooth cam sprocket directly from
the 26 tooth sprocket on the idler sprocket assembly.
A fixed chain guide and a hydraulic oil damped ten-
sioner are used to maintain tension in each second-
ary chain system. The hydraulic tensioners for the
secondary chain systems are fed pressurized oil from
oil reservoir pockets in the block. Each tensioner
incorprates a controled leak path through a device
known as a vent disc located in the nose of the piston
to manage chain loads. Each tensioner also has a
mechanical ratchet system that limits chain slack if
the tensioner piston bleeds down after engine shut
down. The tensioner arms and guides also utilize
nylon wear faces for low friction and long wear. The
secondary timing chains receive lubrication from a
small orifice in the tensioners. This orifice is pro-
tected from clogging by a fine mesh screen which is
located on the back of the hydraulic tensioners.
STANDARD PROCEDURE
MEASURING TIMING CHAIN WEAR
NOTE: This procedure must be performed with the
timing chain cover removed.
(1) Remove the timing chain cover. Refer to Timing
Chain Cover in this section for procedure.
KJENGINE - 3.7L 9 - 71
EXHAUST MANIFOLD (Continued)
crankshaft seal surface is damaged. The seal area on
the crankshaft could have minor nicks or scratches
that can be polished out with emery cloth.
CAUTION: Use extreme caution when crankshaft
polishing is necessary to remove minor nicks and
scratches. The crankshaft seal flange is especially
machined to complement the function of the rear oil
seal.
(6) For bubbles that remain steady with shaft
rotation, no further inspection can be done until dis-
assembled.
(7) After the oil leak root cause and appropriate
corrective action have been identified, replace compo-
nent(s) as necessary.
DIAGNOSIS AND TESTING - ENGINE
Engine diagnosis is helpful in determining the
causes of malfunctions not detected and remedied by
routine maintenance.
These malfunctions may be classified as either
mechanical (e.g., a strange noise), or performance
(e.g., engine idles rough and stalls).Refer to the Engine Mechanical and the Engine
Performance diagnostic charts, for possible causes
and corrections of malfunctions (Refer to 9 - ENGINE
- DIAGNOSIS AND TESTING - MECHANICAL)
(Refer to 9 - ENGINE - DIAGNOSIS AND TESTING
- PERFORMANCE).
For fuel system diagnosis, (Refer to 14 - FUEL
SYSTEM/FUEL DELIVERY - DIAGNOSIS AND
TESTING).
Additional tests and diagnostic procedures may be
necessary for specific engine malfunctions that can-
not be isolated with the Service Diagnosis charts.
Information concerning additional tests and diagno-
sis is provided within the following:
²Cylinder Compression Pressure Test
²Cylinder Combustion Pressure Leakage Test
²Engine Cylinder Head Gasket Failure Diagnosis
²Intake Manifold Leakage Diagnosis
²Lash Adjuster (Tappet) Noise Diagnosis
²Engine Oil Leak Inspection
DIAGNOSIS AND TESTING - ENGINE DIAGNOSIS - PERFORMANCE
CONDITION POSSIBLE CAUSE CORRECTION
ENGINE WILL NOT START 1. Weak battery. 1. Test battery. Charge or replace
as necessary. (Refer to 8 -
ELECTRICAL/BATTERY SYSTEM -
DIAGNOSIS AND TESTING)
2. Corroded or loose battery
connections.2. Clean and tighten battery
connections. Apply a coat of light
mineral grease to terminals.
3. Faulty starter. 3. Test starting system. (Refer to 8 -
ELECTRICAL/STARTING -
DIAGNOSIS AND TESTING)
4. Faulty coil(s) or control unit. 4. Test and replace as needed.
(Refer to Appropriate Diagnostic
Information)
5. Incorrect spark plug gap. 5. Set gap. (Refer to 8 -
ELECTRICAL/IGNITION CONTROL
- SPECIFICATIONS)
6. Contamination in fuel system. 6. Clean system and replace fuel
filter.
7. Faulty fuel pump. 7. Test fuel pump and replace as
needed. (Refer to Appropriate
Diagnostic Information)
8. Incorrect engine timing. 8. Check for a skipped timing
belt/chain.
KJENGINE9s-5
ENGINE - 2.4L (Continued)