PCM - Incorrect Misfire Condition/Flashing MIL
NO: 18-13-98GROUP: Vehicle Performance
DATE: Mar. 13, 1998
SUBJECT:
Incorrect Misfire Detection/Flashing MIL Illumination
MODELS:
1998 (LH) Concorde/Intrepid
NOTE:
THIS BULLETIN APPLIES TO VEHICLES BUILT BEFORE FEB. 16, 1998 MDH (0216XX) EQUIPPED WITH A 2.7L or 3.2L ENGINE.
DISCUSSION:
The OBD II system will monitor the engine for two rates of misfire and illuminate the MIL two different ways depending on the misfire rate as follows:
1. The MIL will be lit solid when misfire is detected at a rate that can cause an increase in emissions but not cause catalyst or engine damage (two trip fault).
2. The MIL will be flashed when misfire is detected at a rate that can cause an increase in emissions and cause catalyst / engine damage (one trip fault).
Based on the above description, an error in software logic causes the flashing MIL to be set for any misfire induced fault. Once this occurs, the MIL will not quit flashing even after catalyst damage is no longer at risk. Finally, the flashing MIL cannot be erased by running three good OBD II trips. The only way to clear the MIL is by erasing it with the DRB Ill.
DIAGNOSIS:
Using the Diagnostic Scan Tool (DRB III) with the appropriate Diagnostic Procedures 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. If DTC's associated with misfire are present along with a flashing MIL, perform misfire diagnostics listed in the 2.7/3.2L LH Powertrain Diagnostics Manual (Publication Number 81-699-97126). After the misfire condition or any other OBD II related fault is identified and corrected, perform the following Repair Procedure.
NOTE:
WHENEVER A POWERTRAIN CONTROL MODULE (PCM) IS REPLACED DUE TO FAILURE, THE SOFTWARE OF THE REPLACEMENT CONTROLLER SHOULD BE VERIFIED FOR THE LATEST REVISION LEVEL. USE THE FLASH PROCEDURE TO UPDATE REPLACED CONTROLLERS AS NECESSARY.
EQUIPMENT/PARTS REQUIRED:
1 CH6000 Scan Tool (DRB III)
1 CH7035 General Purpose Interface Bus Cable (GPIB)
1 CH7000/7001 J1962 Cable
1 04669020 Label - Authorized Software Update
1 04275086 Label - Authorized Modification
NOTE:
THE MDS AND DRB III ARE REQUIRED TO PERFORM THIS REPAIR AND THE SYSTEM MUST BE OPERATING WITH RELEASE 21 OR HIGHER AND TIL CD RELEASE 1153 OR HIGHER MUST BE INSTALLED.
REPAIR PROCEDURE:
This bulletin involves selectively erasing and reprogramming the Powertrain Control Module (PCM) with new software (calibration changes).
1. Connect the MDS (Mopar Diagnostic System) and DRB III (Scan Tool) to the vehicle and power them up.
2. Use the arrow keys and select # 2 MDS DIAGNOSTICS on the DRB III 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 VEHICLE CONTROLLER PROGRAMMING on the MDS, then press NEXT MENU.
5. Use the arrow keys and select PROGRAMMING OF ALL OTHER CONTROLLERS USING MDS & DRB III on the MDS, then press NEXT MENU.
6. Follow the steps presented on the MDS and DRB III which will allow the DRB III to obtain the current part number of the PCM.
7. The MDS will display the part number of the PCM on the vehicle and the appropriate replacement part number, then press NEXT MENU to begin programming.
If the PCM 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. If the PCM has already been updated, then another condition exists that will require further diagnosis and repair.
8. The MDS and DRB III will prompt for any operator 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 04669020 (Figure 1). 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" p/n 04275086 and attach the label near the VECI Label (Figure 2).
POLICY: Reimbursable within the provisions of the warranty.
TIME ALLOWANCE:
Labor Operation No: 08-19-49-96 0.5 Hrs.
FAILURE CODE: FM - Flash Module