Torque Converter Clutch - Erratic Operation: Overview
NUMBER: 18-02-99GROUP: Vehicle Performance
DATE: Feb. 19, 1999
SUBJECT:
Erratic Torque Converter Clutch (TCC) Operation (5.9L Diesel Applications)
OVERVIEW:
This bulletin involves selectively erasing and reprogramming the Powertrain Control Module (PCM) with new software (calibration changes 98cal12 & 99cal14).
MODELS:
1998 - 1999 (BR/BE) Ram Truck
NOTE:
THIS INFORMATION APPLIES TO VEHICLES EQUIPPED WITH A 5.9L 24 VALVE DIESEL ENGINE AND AUTOMATIC TRANSMISSION BUILT BETWEEN JAN. 1, 1998 AND DEC. 18, 1998 (MDH 0101XX & 1218XX).
SYMPTOM/CONDITION:
Some vehicles may experience a surge like condition while in 4th gear. This may be caused by the Torque Converter Clutch (TCC) unlocking and locking when it should be consistently locked. The cause of this erratic operation has been identified as electrical noise from the Throttle Position Sensor (TPS) or Alternator.
DIAGNOSIS:
Using the Mopar Diagnostic System (MDS/MDS2) and or the Diagnostic Scan Tool (DRB III(R)) 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.
Verify the condition by creating a custom display in the DRB III(R) and include the following: SENSORS (Output Shaft Speed, TPS Volts, Trans Temp Degree) & INPUTS/OUTPUTS (Brake Switch, Park/Neutral, ASD Relay Sense, Desired TC Clutch).
Drive the vehicle with a helper monitoring the DRB III(R). Warm the engine and verify the transmission fluid temperature is greater than 32°F and consistent. Operate the vehicle with an output shaft speed greater than 2200 rpm. Verify that the brake switch shows a released status that is consistent and verify the park/neutral status reads D/R and is consistent. While keeping the output shaft speed above 2200 rpm, hold the throttle so the TPS reads 1 volt. Monitor the TC clutch status, it should be consistently locked. If the TC clutch status shows unlocking/locking, look to see if the TPS volts are fluctuating by 0.2 volts or more. It the conditions are met, perform the Repair Procedure. If a surge like condition is felt but the above test does not confirm the TCC unlocking/locking occurrence, further diagnosis and testing will be required.
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 CH6000 Scan Tool (DRB III(R))
1 CH7035 General Purpose Interface Bus Cable (GPIB)
1 CH7000/7001 J1962 Cable
1 MDS1 or MDS2
NOTE:
THE MDS1/MDS2 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 1179 OR HIGHER MUST BE INSTALLED. IF USING THE MDS2 AND DRB III(R) THE SYSTEM MUST BE OPERATING AT CIS CD2030 OR HIGHER.
POLICY: Reimbursable within the provisions of the warranty.
TIME ALLOWANCE:
Labor Operation No: 08-19-42-95 0.5 Hrs.
FAILURE CODE: FM - Flash Module