PCM - Deceleration Shudder At Low Engine Speeds
NO.: 18-12-93GROUP: Driveability
DATE: Oct. 22, 1993
SUBJECT:
Decel Shudder at Low Engine Speed
MODELS:
1992 - 1993 (AC) Dynasty/New Yorker/New Yorker Salon
(AS) Caravan/Grand Caravan/Caravan C/V
Voyager/Grand Voyager/Town & Country
(AY) Imperial/New Yorker Fifth Avenue
NOTE:
THIS BULLETIN APPLIES TO VEHICLES EQUIPPED WITH 3.3L OR 3.8L ENGINE AND THE 41TE TRANSAXLE.
NOTE:
IF TECHNICAL SERVICE BULLETIN NO. 09-13-93 HAS BEEN APPLIED TO THE VEHICLE, THE REPAIR FOR DECEL SHUDDER IS ALREADY INSTALLED.
SYMPTOM/CONDITION:
In gear closed throttle decel vibrations or shudder between 40 and 25 MPH. (The actual speed range will vary depending on the vehicles final drive gear ratio.)
DIAGNOSIS:
Using the Scan Tool (DRB II) and appropriate diagnostic procedure manual or the Mopar Diagnostic System, verify that all vehicle engine systems are functioning as designed. If Trouble Codes (Diagnostic Trouble Codes) are present, record them on the repair order for future reference, and repair as necessary. If no codes are present and all systems are functioning correctly, proceed with the following repair.
PCM (Powertrain Control Module) RE-PROGRAMMING
This repair involves selectively erasing and programming the Powertrain Control Module with new software (calibrations).
EQUIPMENT/PARTS REQUIRED:
MULTI-PART NUMBER FLASH RE-PROGRAMMING INSTRUCTIONS
1. Insert the Flash Programming Cartridge into the DRB-II.
2. Connect the DRB-II to the Flash Programming Adapter.
3. Connect the Flash Programming Adapter to the Engine 6-Way Cable.
4. Connect the Engine 6-Way Cable to the Engine Diagnostic Connector.
5. Connect the Engine 6-Way Cable Red Battery Clip to the Positive Terminal of the Vehicle Battery.
6. Turn the vehicle ignition on.
7. The DRB-II Will Power Up and Prompt Through the Sequence of Windows as Shown:
8. When the Update is Complete, Turn the Vehicle Ignition Off.
NOTE:
If an error happens, write down the error message (off the Scan Tool screen). Then press MODE and ATM keys together on the Scan tool to retry (reboot).
The under hood temperature during programming Must be between -40 degrees F (-40 degrees C) and +185 degrees F (+85 degrees c).
9. IMPORTANT:
THIS STEP IS REQUIRED BY LAW. Type the necessary information on the "Authorized Software Update Label" and attach to the PCM.
10. Type the necessary information on the Authorized Modification Label and attach the label near the VECI Label.
1992 Federal Emission Vehicles Only - EFFECTIVE DATE: 11-12-93
The 1992 AC, AS, & AY Models, With FEDERAL EMISSIONS, do not have "Flash" capacity in the PCM. Therefore, these vehicles will require the replacement of the Powertrain Control Module with one that has revised software.
PARTS REQUIRED:
REPAIR PROCEDURE:
This repair involves the replacement of the Powertrain Control Module with a module that has revised software.
1. With the ignition switch in the OFF position, disconnect the battery.
2. Remove the PCM as outlined in the appropriate service manual, and replace it with a unit called out in PARTS REQUIRED.
3. Connect the battery.
4. Type the required information on the Authorized Modification Label, as illustrated, and attach near the VECI Label.
POLICY:
Reimbursable within the provisions of the warranty.
TIME ALLOWANCE:
Labor Operation No. 08-19-92-99 Replace PCM - 1992 Fed 0.4 Hrs.
08-19-40-91 Reprogram PCM - 1992 CA/1993 All 0.3 Hrs.
FAILURE CODE:
FM - Reprogram Module - 1992 CA/1993 All
AM - Authorized Modification - 1992 Fed.