PCM - Cruise Control Malfunctions: Overview
Number: 18-08-99Group: Vehicle Performance
Date: April 30, 1999
SUBJECT:
Improved Speed Control System Sensitivity To Set Speed.
OVERVIEW:
This bulletin involves selectively erasing and reprogramming the JTEC Powertrain Control Module (PCM) with new software (calibration changes 98CaI12A, 99CaI17). There is no change to the Cummins CM551 Engine Control Module (ECM) software.
MODELS:
1998 - 1999 (BR/BE) Ram Truck
NOTE:
THIS INFORMATION APPLIES TO VEHICLES EQUIPPED WITH A 5.9L - 24V DIESEL ENGINE BUILT BEFORE MARCH 23, 1999 (MDH 0323XX).
SYMPTOM/CONDITION:
Some customers may complain that their vehicle speed control system may be too busy or drift more than 2 mph below or above the initial vehicle set speed. Vehicle load and road I terrain conditions may impact this issue.
The new PCM software improves the speed control system sensitivity so that the vehicle speed remains closer to its set speed with fewer engine rpm oscillations.
DIAGNOSIS:
Using the Mopar Diagnostic System (MDS/MDS2) and or the Diagnostic Scan Tool (DRB Ill�) 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 no DTC's are present, and the above symptoms have been experienced, perform the Repair Procedure.
NOTE:
WHENEVER A POWERTRAIN CONTROL MODULE (PCM) IS REPLACED DUE TO FAILURE, THE SOFTWARE OF THE REPLACEMENT CONTROLLER MUST BE VERIFIED FOR THE LATEST REVISION LEVEL. USE THE FLASH PROCEDURE TO UPDATE REPLACED CONTROLLERS AS NECESSARY.
PARTS REQUIRED:
1 04669020 Label, Authorized Software Update
1 04275086 Label, Authorized Modification
EQUIPMENT REQUIRED:
1 CH6OOO Scan Tool (DRB III(R))
1 CH7035 General Purpose Interface Bus Cable (GPIB)
1 CH7OOO/7001 J1962 Cable
1 MDS1 or MDS2
NOTE:
THE MDS1IMDS2 AND DRB III(R) ARE REQUIRED TO PERFORM PART OF THIS REPAIR. IF USING THE MDS1 AND DRB III(R). THE MDS MUST BE OPERATING AT RELEASE 21 OR HIGHER AND TIL CD RELEASE 1132 OR HIGHER MUST BE INSTALLED. IF USING THE MDS2 AND THE DRB III(R) THE SYSTEM MUST BE OPERATING AT CIS CD2031 OR HIGHER.
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