Replace and program the Powertrain Control Module per Service Information.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
8.GENERATOR BELT CONDITION
Turn the ignition off.
NOTE: Battery condition must be verified prior to this test.
Inspect the Generator Belt tension and condition.
Is the Generator Belt OK?
Ye s>>
Go To 9
No>>
Repair as necessary.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
9.ACTIVE DTC SET
Start the engine.
Turn on all accessories.
Raise engine speed to 2000 RPM for 30 seconds then return to idle.
With the scan tool, read DTCs.
Are there any
Charging SystemTrouble Codes?
Ye s>>
Refer to DTC list for the related Charging DTCs.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 10
10.WIRE HARNESS INSPECTION
Ignition on, engine not running.
With the scan tool, actuate the Generator Field Driver.
Using a 12-volt test light, backprobe the Generator Field Driver Terminalat the back of the Generator.
NOTE: The test light should blink On and Off every 1.4 seconds.
While monitoring the 12-volt test light, wiggle the Field Terminals back to the PCM and ASD Relay.
Was there any interruption in the normal cycle of the test light?
Ye s>>
Repair the wire or connector where the wiggling interrupted the voltage cycle.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Te s t C o m p l e t e .
3.(Z130) AND (Z131) PCM GROUND CIRCUITS
Turn the ignition off.
Using a 12-volt test light connected to battery voltage, probe the (Z130)
and (Z131) PCM ground circuits in the C1 PCM harness connector.
Does the test light illuminate brightly?
Ye s>>
Te s t C o m p l e t e .
No>>
Repair the open in the (Z130) and (Z131) PCM ground cir-
cuits.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)
NOTE: If this vehicle is equipped with an Electronic Throttle Control system, and the APP Sensors, PCM, or
Throttle Body Assembly have been replaced, use the scan tool to perform theETC RELEARN function.
14. If the indicator ball shows a leak present, perform the smoke test indicated in the previous test and identify the
leak and repair. Perform this verification test when the repair is complete.
Didtheindicatorballindicatethealeakispresent?
Ye s>>
Repeat the DTC test to identify the leak and repair.
No>>
Repair is complete.
5.POWERTRAIN VERIFICATION TEST 4
NOTE: 1. After completing the Powertrain Verification Test the Transmission Verification Test must be per-
formed.
NOTE: 2. If the PCM has been replaced and the correct VIN and mileage have notbeen programmed, a DTC
will set in the ABS Module, Airbag Module and the SKIM/SKREEM.
NOTE: 3. If the vehicle is equipped with a Sentry Key Remote Entry, Secret Key data must be updated. Refer
to the Service Information for the PCM, SKIM/SKREEM and the Transponder (ignition key) for programming
information. Using the scan tool, program the Secret Key information intothe PCM using the PCM replaced
function under the WCM menu.
NOTE: 4. If this vehicle is equipped with an Electronic Throttle Control system, and the APP Sensors, PCM,
or Throttle Body Assembly have been replaced, use the scan tool to perform the ETC RELEARN function.
NOTE: 5. When replacing an O2 Sensor, the PCM RAM memory must be cleared, either by disconnecting the
PCM C1 connector or momentarily disconnecting the Battery negative terminal.
6. The NGC learns the characteristics of each O2 heater element and these old values should be cleared when
installing a new O2 sensor. The customermay experience driveability issues if this is not performed.
7. Inspect the vehicle to make sure that all engine components are properlyinstalled and connected. Reassemble
and reconnect components as necessary.
8. Connect the scan tool to the data link connector.
9. Make sure the fuel tank has at least a quarter tank of fuel. Turn off all accessories.
10. If the Catalyst was replaced, with the scan tool go to the MiscellaneousMenu Option
Catalyst Replacedand
press enter.
11. If a Comprehensive Component DTC was repaired, perform steps 12 - 14. Ifa Major OBDII Monitor DTC was
repaired skip those steps and continue verification.
12. After the ignition has been off for at least 10 seconds, restart the vehicle and run 2 minutes.
13. With the scan tool, monitor the appropriate pre-test enabling conditions until all conditions have been met. Once
the conditions have been met, switch screen to the appropriate OBDII monitor, (Audible beeps when the monitor is
running).
14. If the repaired OBDII trouble code has reset or was seen in the monitor while on the road test, the repair is not
complete. Check for any related technical service bulletins or flash updates and return to Engine Electrical Diag-
nostic List.
15. If the conditions cannot be duplicated, erase all DTCs with the Scan tool.
16. If another DTC has set, return to the Engine Electrical Diagnostic Listand follow the path specified for that DTC.
Did the OBDII Monitor run successfully and has the Good Trip Counter changed to one or more?
Ye s>>
Repair is complete.
No>>
Check for any related Technical Service Bulletins and/or refer to the appropriate Diagnostic Procedure.
(Refer to 9 - ENGINE - DIAGNOSIS AND TESTING) - PERFORMANCE and (Refer to 9 - ENGINE - DIAGNOSIS
AND TESTING)—MECHANICAL 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 - DIAGNO-
SIS AND TESTING) for the fuel system diagnosis.
Additional tests and diagnostic procedures may be necessary for specificengine malfunctions that can not be iso-
lated with the Service Diagnosis charts. Information concerning additional tests and diagnosis is provided within the
following diagnosis:
Cylinder Compression Pressure Test (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).
Cylinder Combustion Pressure LeakageTest (Refer to 9 - ENGINE - DIAGNOSISAND TESTING).
Engine Cylinder Head Gasket Failure Diagnosis (Refer to 9 - ENGINE/CYLINDER HEAD - DIAGNOSIS AND
TESTING).
Intake Manifold Leakage Diagnosis (Refer to 9 - ENGINE/MANIFOLDS/INTAKEMANIFOLD - 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.
3. Faulty coil. 3. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/IGNITION
COIL - REMOVAL).
4. Incorrect cam timing. 4. (Refer to 9 - ENGINE/VALVE
TIMING - STANDARD
PROCEDURE).
CONDITION POSSIBLE CAUSES CORRECTION
OIL PUMPING AT RINGS; SPARK
PLUGS FOULING1. Worn or damaged rings. 1. Hone cylinder bores and replace
rings.
2. Carbon in oil ring slots. 2. Replace rings (Refer to 9 -
ENGINE/ENGINE BLOCK/PISTON
RINGS - STANDARD
PROCEDURE).
3. Incorrect ring size installed. 3. Replace rings (Refer to 9 -
ENGINE/ENGINE BLOCK/PISTON
RINGS - STANDARD
PROCEDURE).
4. Worn valve guides. 4. Ream guides and replace valves
(Refer to 9 - ENGINE/CYLINDER
HEAD/INTAKE/EXHAUST VALVES
& SEATS - STANDARD
PROCEDURE).
5. Leaking valve guide seals. 5. Replace valve guide seals.
DIAGNOSIS AND TESTING - CYLINDER COMPRESSION PRESSURE
The results of a cylinder compressionpressure test can be utilized to diagnose several engine malfunctions.
Ensurethebatteryiscompletelychargedandtheenginestartermotorisingood operating condition. Otherwise the
indicated compression pressures may not be valid for diagnosis purposes.
1. Clean the spark plug recesses with compressed air.
2. Remove the spark plugs.
3. Disable the fuel system (Refer to 14 - FUEL SYSTEM/FUEL DELIVERY - DESCRIPTION).
4. Remove the ASD relay (Refer to 8 - ELECTRICAL/IGNITION CONTROL/AUTO SHUTDOWNRELAY-
REMOVAL).
5. Insert a compression pressure gauge and rotate the engine with the engine starter motor for three revolutions.
6. Record the compression pressure on the 3rd revolution. Continue the test for the remaining cylinders.
7. (Refer to 9 - ENGINE - SPECIFICATIONS) for the correct engine compression pressures.
DIAGNOSIS AND TESTING - CYLINDERCOMBUSTION PRESSURE LEAKAGE
The combustion pressure leakage test provides an accurate means for determining engine condition.
Combustion pressure leakage testing will detect:
Exhaust and intake valve leaks (improper seating).
Leaks between adjacent cylinders or into water jacket.
Any causes for combustion/compression pressure loss.
1. Check the coolant level and fill as required. DO NOT install the radiatorcap.
2. Start and operate the engine until it attains normal operating temperature, then turn the engine OFF.
3. Remove the spark plugs.
4. Remove the oil filler cap.
5. Remove the air cleaner hose.
6. Calibrate the tester according to the manufacturer’s instructions. The shop air source for testing should maintain
483 kPa (70 psi) minimum, 1,379 kPa (200 psi) maximum and 552 kPa (80 psi) recommended.
7. Perform the test procedures on each cylinder according to the tester manufacturer’s instructions. Set piston of
cylinder to be tested at TDC compression,While testing, listen for pressurized air escaping through the throttle
body, tailpipe and oil filler cap opening. Check for bubbles in the radiator coolant.
All gauge pressure indications should be equal, with no more than 25% leakage.
FOR EXAMPLE:At 552 kPa (80 psi) input pressure, a minimum of 414 kPa (60 psi) should be maintained in the
cylinder.
REMOVAL
1. Disconnect the battery negative cable.
2. Remove air cleaner assembly.
3. Remove radiator core support bracket.
4. Remove fan shroud with viscous fan assembly.
5. Remove drive belt.
6. Remove A/C compressor (2) and secure away from
engine.
7. Remove generator (3) and secure away from
engine.
NOTE: Do NOT remove the phenolic pulley from
the P/S pump. It is not required for P/S pump
removal.
8. Remove power steering pump with lines attached
and secure away from engine.
9. Drain cooling system.
10. Disconnect the heater hoses from the engine.
11. Disconnect heater hoses from heater core and
remove hose assembly.
12. Disconnect throttle and speed control cables.
13. Remove upper radiator hose from engine.
14. Remove lower radiator hose from engine.
15. Remove radiator/cooling module assembly.
16. Disconnect the engine to body ground straps at
theleftsideofcowl.
34. Install the A/C compressor (2).
35. Install the drive belt.
36. Install the fan shroud with the viscous fan assem-
bly.
37. Install the radiator core support bracket.
38. Install the air cleaner assembly.
39. Refill the engine cooling system.
40. Recharge the air conditioning.
41. Check and fill engine oil.
42. Connect the battery negative cable.
43. Start the engine and check for leaks.
SPECIFICATIONS
SPECIFICATIONS - 3.7L ENGINE
GENERAL SPECIFICATIONS
DESCRIPTION SPECIFICATION
Type 90°SOHCV612Valve
Number of Cylinders 6
Firing Order 1-6-5-4-3-2
Lead Cylinder No. 1 Left Bank
Compression Ratio 9.6:1
Max. Variation Between Cylinders 25%
Metric Standard
Displacement 3.7 Liters 226 Cubic Inches
Bore 93.0 mm 3.66 in.
Stroke 90.8 mm 3.40 in.
Horsepower 211 @ 5200 RPM
Torque 236ft. lbs.@4000 PRM
Compression Pressure 1172-1551 kPa 170-225 psi
CYLINDER BLOCK
DESCRIPTION SPECIFICATION
Metric Standard
Bore Diameter 93.013 ± .0075 mm 3.6619 ± 0.0003 in.
Out of Round (MAX) 0.076 mm 0.003 in.
Taper (MAX) 0.051 mm 0.002 in.
PISTONS
HEAD-CYLINDER-LEFT
DIAGNOSIS AND TESTING - CYLINDER HEAD GASKET
A cylinder head gasket leak can be located between adjacent cylinders or between a cylinder and the adjacent
water jacket.
Possible indications of the cylinder head gasket leaking between adjacent cylinders are:
Loss of engine power
Engine misfiring
Poor fuel economy
Possible indications of the cylinder head gasket leaking between a cylinder and an adjacent water jacket are:
Engine overheating
Loss of coolant
Excessive steam (white smoke) emitting from exhaust
Coolant foaming
CYLINDER-TO-CYLINDER LEAKAGE TEST
To determine if an engine cylinder head gasket is leaking between adjacentcylinders, follow the procedures in Cyl-
inder Compression Pressure Test (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING). An engine cylinder head
gasket leaking between adjacent cylinders will result in approximately a50 - 70% reduction in compression pres-
sure.
CYLINDER-TO-WATER JACKET LEAKAGE TEST
WARNING: USE EXTREME CAUTION WHEN THE ENGINE IS OPERATING WITH COOLANT PRESSURE CAP
REMOVED.
VISUAL TEST METHOD
With the engine cool, remove the coolant pressure cap. Start the engine andallow 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.EXCESSIVE
PRESSURE BUILT UP, BY CONTINUOUS ENGINE OPERATION, MUST BE RELEASED TO A SAFE PRESSURE
POINT. NEVER PERMIT PRESSURE 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 the negative cable from the battery.
2. Raise the vehicle on a hoist.
3. Disconnect the exhaust pipe at the left side exhaust manifold.
4. Drain the engine coolant (Refer to 7 - COOLING - STANDARD PROCEDURE).
5. Lower the vehicle.
6. Remove the intake manifold (Refer to 9 - ENGINE/MANIFOLDS/INTAKE MANIFOLD - REMOVAL).