A/T - Harsh Upshifts, at 50 mph Under Light Throttle
44-21DATE: 9/94
MODEL: XJ6 Sedan Ran C 92-93 MY, XJS (4.0L) Range 92 MY, as listed:
SUBJECT:
Automatic Transmission - Shift Quality - Install Modified TCM
ISSUE:
Harsh upshift may occur under light throttle at 50 MPH.
A modified TCM (P/N LMA 2400AA) is available for the following vehicles which significantly improves shift quality with the transmission mode switch in the NORMAL position.
^ XJ6 Sedan Range From VIN 629286 - 667829
^ XJS (4.0L) Range From VIN 179735 - 185820
ACTION:
If customers complain of harsh upshifts, at 50 MPH under light throttle, perform the following procedure.
Procedure:
1. Use JDS or PDU to interrogate the TCM for DTCs. If DTCs are present, refer to the appropriate Service Manual for repair information.
2. Ensure that the following are not contributing to the shift quality problem.
^ Engine mechanical condition
^ Engine management system
^ Incorrect transmission oil level
^ Incorrect selector cable adjustment
^ Incorrect rotary switch adjustment
3. Verify that the correct transmission and TCM are fitted to the vehicle.
Transmission Part Number EBC 4409
TCM Part Number DBC 10110
IMPORTANT:
DO NOT replace the TCM unless the customer complaint persists after Steps 1.2 and 3 am performed.
4. Replace TCM (P/N DBC 10110) with modified TCM (P/N LMA 2400AA).
PARTS INFORMATION:
DESCRIPTION PART NUMBER
Transmission control module LMA 2400AA
WARRANTY INFORMATION:
FAULT CODE FG GC GR
R.O. NUMBER 44.15.32
DESCRIPTION Transmission control module - Renew
TIME ALLOWANCE 0.75 hrs.