PCM, A/T - Vibration or Perceived Engine Miss
NO: 21-04-95GROUP: Transmission
DATE: Apr. 14, 1995
SUBJECT:
Vibration or Perceived Engine Miss
MODELS:
1994 - 1995 (BR) Ram Truck
NOTE:
THIS BULLETIN APPLIES TO VEHICLES EQUIPPED WITH THE CUMMINS DIESEL ENGINE AND AUTOMATIC TRANSMISSION.
SYMPTOM/CONDITION:
A vibration or perceived engine miss at approximately 1100 RPM as the torque convertor clutch engages. This condition occurs in 4th gear at speeds between 42 to 48 MPH.
DIAGNOSIS:
After duplicating the above condition, verity the part number on the Powertrain Control Module (PCM). For proper repair procedure, refer to the guidelines given below.
1. If the vehicle is a 1994 MY equipped with PCM P/N 56027303 or 56027304, replace the PCM with P/N 4798745. Proceed to the PCM replacement section of this TSB.
2. If the vehicle is a 1995 MY, verify that it is equipped with PCM P/N 56028335 or 56028336, and proceed to the PCM reprogramming section of this TSB.
If the vehicle is equipped with a PCM other than 56028335, 56028336, 04798745, or 04856080, replace the PCM with P/N 4798745 and proceed to the PCM replacement section of this TSB.
NOTE:
IF THE VEHICLE IS EQUIPPED WITH PCM P/N 4798745 OR 4856080, THE SOFTWARE UPDATE NEEDED TO ADDRESS THIS TSB ISSUE HAS ALREADY BEEN COMPLETED AND NO FURTHER ACTION IS REQUIRED.
PARTS REQUIRED:
1 04798745 Module, Powertrain Control (1994 Only)
1 4669020 Label - Authorized Software Update
1 4275086 Label - Authorized Modification
EQUIPMENT REQUIRED:
1 CH6000 Scan Tool (DRB III)
1 CH7000 General Purpose Interface Bus Cable (GPIB)
1 CH7015 Cable
REPAIR PROCEDURE/MODULE REPLACEMENT:
This section of the bulletin involves the replacement of the Powertrain Control Module (PCM) with P/N 4798745.
1. Record all radio station presets.
2. Disconnect negative battery cable at battery.
3. Remove 60 way electrical connector from PCM (one bolt). PCM is located in the right rear side of the engine compartment.
4. Remove the three PCM mounting bolts and remove.
5. Install new PCM, P/N 4798745. Torque bolts to 1 Nm (9 in. lbs.) torque.
6. Connect 60 way electrical connector to PCM. Torque bolt to 4 Nm (35 in. lbs.).
7. Connect negative battery cable to battery.
8. Program radio station presets and clock.
MODULE REPROGRAMMING:
This section of the bulletin involves reprogramming the Powertrain Control Module with new software and installation of appropriate labels.
NOTE:
THE MOPAR DIAGNOSTIC SYSTEM IS REQUIRED TO PERFORM THE FOLLOWING REPAIR. THE SYSTEM MUST BE OPERATING WITH RELEASE 16 OR HIGHER INSTALLED (TIL CD 1075 OR LATER).
This repair involves recalibrating the Powertrain Control Module with new software (calibration change).
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 controller on the vehicle and compare it to the part number displayed. If the controller has already been updated, no further action is needed.
8. The MDS and DRBIII will prompt for any operator action needed during the remainder of the programming process.
NOTE:
THE FOLLOWING STEPS ARE REQUIRED BY LAW.
Authorized Software Modification Decal:
9. Type the necessary information on the "Authorized Software Update Label" and cover with the clear plastic sticker provided with label. Attach label to the flat surface area located to the left of the 60 way electrical connector on the PCM.
Authorized Modification Decal:
10. Type the necessary information on the Authorized Modification Label and attach the label near the VECI Label.
POLICY: Reimbursable within the provisions of the warranty.
TIME ALLOWANCE:
Labor Operation No: 08-19-41-97 0.7 Hrs
1994 (BR) Module, Powertrain Control
Replace then Reprogram
08-19-41-98 0.7 Hrs.
1995 (BR) Module, Powertrain Control
Replace then Reprogram
08-19-41-99 0.5 Hrs.
1995 (BR) Module, Powertrain Control Reprogram
FAILURE CODE: FM - Flash Module