PCM - Intermittent OBDII Faults/Driveability Concerns
NO: 18-19-95GROUP: Vehicle Performance
DATE: May 19, 1995
SUBJECT:
Cold Start Tip-In Stumble Or
Diagnostic Trouble Codes
(DTC's) 25, 52 Or 66
MODELS:
1996 (NS) Town & Country/Caravan/Voyager
NOTE:
THIS BULLETIN APPLIES TO VEHICLES EQUIPPED WITH A 3.3L OR 3.8L ENGINE BUILT PRIOR TO APR. 7, 1995.
SYMPTOM/CONDITION:
Some vehicles on rare occasions may exhibit any of the following symptoms:
Cold tip-in stumble, most likely to occur immediately after shifting from Park or Neutral to Drive if the engine was partly warmed up in Park or Neutral or is returned to Park or Neutral part way through the warm up.
Erroneous On Board Diagnostics II (OBDII) "Target Idle Not Reached" fault (MIL/Check Engine Light and DTC 25, Hex Code 8A), most likely to occur after a hard stop that caused the Antilock Brake System (ABS) to be activated.
Erroneous OBDII "No CCD (Chrysler Collision Detection) Messages From TCM (Transmission Control Module)" fault (MIL/Check Engine Light and DTC 66, Hex Code 60), most likely to occur if the ignition switch is held in the start position for more than 10 seconds with the engine running.
OBDII "Fuel System Rich" fault (MIL/Check Engine Light and DTC 52, Hex Code 76), most likely to occur in high ambient with high Reid Vapor Pressure (RVP) fuel.
DIAGNOSIS:
Using the Mopar Diagnostic System (MDS) or the Scan Tool (DRBIII) with the appropriate Diagnostic Procedure Manual, verify all engine/transmission systems are functioning as designed. If Diagnostic Trouble Codes (DTC's) are present, record them on the repair order and repair as necessary before proceeding further with this bulletin.
EQUIPMENT/PARTS REQUIRED:
1 CH6000 Scan Tool (DRBIII)
1 CH7035 General Purpose Interface Bus Cable (GPIB)
1 CH7000 J1962 Cable
1 4669020 Label - Authorized Software Update
1 4275086 Label - Authorized Modification
REPAIR PROCEDURE:
This bulletin involves selectively erasing and reprogramming the Powertrain Control Module (PCM) with new software (Flashing).
NOTE:
MDS AND DRBIII ARE REQUIRED TO PERFORM THE FOLLOWING REPAIR. MDS MUST BE OPERATING WITH RELEASE 16 OR HIGHER AND TIL CD 1079 OR HIGHER INSTALLED.
1. Connect the MDS (Mopar Diagnostic System) and DRBIII (Scan Tool) to the vehicle and power them up.
2. Use the arrow keys and select # 2 MDS DIAGNOSTICS on the DRBIII MAIN MENU Screen.
3. Use the arrow keys and select DIAGNOSTIC MENU on the MDS, then press NEXT MENU.
4. Use the arrow keys and select CONTROLLER PROGRAMMING on the MDS, then press NEXT MENU.
5. Use the arrow keys and select PROGRAM CONTROLLER PART on the MDS, then press NEXT MENU.
6. Follow the steps presented on the MDS and DRBIII which will allow the DRBIII to obtain the current part number of the controller.
7. The MDS will display the part number of the controller on the vehicle and the appropriate replacement part number, then press NEXT MENU to begin programming.
If the controller on the vehicle has already been updated or programmed, a NO UPDATES AVAILABLE message will be displayed. Check the part number of the PCM on the vehicle and compare it to the part number displayed.
ENGINE OLD PCM PART NUMBER NEW PCM PART NUMBER
3.3L 4727133 4727139
3.8L 4727134 4727140
If the PCM has already been updated, skip to step 9.
8. The MDS and DRBIII will prompt the operator for any action needed during the remainder of the programming process.
NOTE:
THE FOLLOWING STEPS ARE REQUIRED BY LAW.
9. Type the necessary information on the "Authorized Software Update" label, P/N 4669020. Attach the label to the PCM and cover the label with the clear plastic overlay.
10. Type the necessary information on the Authorized Modification Label and attach the label near the Vehicle Emission Control Information (VECI) Label.
POLICY: Reimbursable within the provisions of the warranty.
TIME ALLOWANCE:
Labor Operation No: 08-19-42-96 0.5 Hrs.
FAILURE CODE: FM - Flash Module