A/T - Reliability Concerns For Extreme Cold Operation
NUMBER: 21-004-01GROUP: Transmission
DATE: Feb. 16, 2001
SUBJECT:
Overdrive Disabled To Improve Transmission Reliability During Cold Temperature Operation
OVERVIEW:
This bulletin involves selectively erasing and reprogramming the Powertrain Control Module (PCM) with new software (calibration level 01Cal14).
MODELS:
2001 (BR/BE) Ram Truck
NOTE:
THIS BULLETIN APPLIES TO VEHICLES: EQUIPPED WITH AN RE AUTOMATIC TRANSMISSION, THE VEHICLE WAS BUILT ON OR BETWEEN JUNE 26, 2000 (MDH0626XX) AND DECEMBER 23, 2000 (MDH 1223XX), AND THE PCM SOFTWARE LEVEL IS EARLIER (LOWER) THAN CALIBRATION 14 FOR MODEL YEAR 2001.
SYMPTOM/CONDITION:
Quality analysis has determined that insufficient lubrication of certain internal transmission components may occur when a vehicle is operated in temperatures lower than -20°C (-5F). This condition may be caused by the automatic transmission fluid (ATF) freezing in the cooler lines and interrupting the flow of lubricating oil (ATF) to the transmission overdrive unit. This condition should only be a concern in areas where very cold ambient temperatures of -20°C (-5°F) are experienced.
The revised software will not allow 4th gear overdrive to occur if ambient temperatures are less than -20°C (-5F). The revised PCM software has been implemented to improve transmission reliability. The customer should be informed that reduced fuel economy would be expected when overdrive is not in use.
DIAGNOSIS:
1. Verify the calibration level of the PCM software. If the PCM software level is at 2001 Calibration 14, or higher, this bulletin does not apply.
2. Perform the Repair Procedure if vehicle operation occurs in ambient temperatures which are less than -20°C (-5°F) and if the PCM software level is earlier (lower or less) than 2001 Calibration 14.
PARTS REQUIRED:
EQUIPMENT REQUIRED:
NOTE:
THE MDS2 MUST BE OPERATING AT CIS CD 2077 OR HIGHER.
REPAIR PROCEDURE:
1. Reprogram the PCM using the MDS2 (Mopar Diagnostic System) and the DRBIII(R) (Scan Tool).
NOTE:
DUE TO THE PCM REPROGRAMMING PROCEDURE, A DTC MAY BE SET IN OTHER MODULES (TCM, TCCM, ECM, BCM, MIC, SKIM, ETC.) WITHIN THE VEHICLE, IF SO EQUIPPED. SOME DTC'S MAY CAUSE THE MIL TO ILLUMINATE. ALL DTC'S RELATE TO A LOSS OF COMMUNICATIONS WITH THE MODULE THAT IS BEING REPROGRAMMED. CHECK ALL MODULES, RECORD THE FAULTS, AND ERASE THESE FAULTS PRIOR TO RETURNING THE VEHICLE TO THE CUSTOMER. ERASE ANY FAULTS IN THE PCM ONLY AFTER ALL OTHER MODULES HAVE HAD THEIR FAULTS ERASED.
NOTE:
THE FOLLOWING STEPS ARE REQUIRED BY LAW.
2. Type the necessary information on the "Authorized Software Update Label" p/n 04669020 (Fig. 1). Attach the label to the PCM and cover the label with the clear plastic overlay.
3. Type the necessary information on the "Authorized Modification Label" p/n 04275086 and attach the label near the VECI label (Fig. 2).
POLICY:
Reimbursable within the provisions of the warranty.
TIME ALLOWANCE:
FAILURE CODE: