MIL - Stays ON After Starting DTCs P1768 and P1773

March 18, 1997

BULLETIN NO.
97-011

YEAR
1997

MODEL
3.0 CL

VIN APPLICATION
Thru 19UYA22..VL008536

MIL Stays On After Starting

SYMPTOM

The Malfunction Indicator Lamp (MIL) stays on after starting the engine, and the PCM Tester shows SAE codes P1768 and P1773 (the MIL flashes DTCs 16 and 23 if you use the SCS service connector) in the A/T Menu.

^ If both DTCs are indicated, go to CORRECTIVE ACTION.

^ If the MIL is on, but you cannot read the DTCs with the PGM Tester, go to DIAGNOSIS to confirm the symptom.

NOTE:
When the initial malfunction occurs, the MIL stays on and the D4 light flashes. The D4 light will not flash again during the next driving cycle unless the malfunction occurs again.

PROBABLE CAUSE

Electrical spikes from the ignition switch affect the TCM.

DIAGNOSIS

1. Connect the PCM Tester, and display the DTCs in the A/T Menu. If it displays "No Communication," connect the red 16/16 DLC adapter to the 16/14 pin O8D II Type 3 adapter (see SPECIAL TOOLS REQUIRED). This adapter must be used on vehicles thru VIN 19UYA22...VL006629.

2. If the PGM Tester displays "No A/T DTCs," select Generic OBD II mode to retrieve the SAE codes.

3. If both SAE codes P1768 and P1773 are indicated, go to CORRECTIVE ACTION. If only one code is present, disregard this bulletin and follow the troubleshooting procedures in section 14 of the service manual.

CORRECTIVE ACTION

Replace the Transmission Control Module (TCM).

REPAIR PROCEDURE

1. Remove the right door sill molding.

2. Pull the passenger's floor carpet back to expose the ECM cover.





3. Remove the ECM cover mounting nuts, then turn the cover over.





4. Remove the TCM by disconnecting the two connectors and removing the three mounting bolts.

5. Install the new TCM in the reverse order of removal, and reinstall all removed parts

6. Record the customer's radio station presets, and the radio anti-theft code.

7. Pull the BACK-UP (10 A) fuse from the under-hood fuse box for 10 seconds to reset the ECM and TCM.

8. Enter the radio anti-theft code, and the radio station presets. Reset the clock.

PARTS INFORMATION

Transmission Control Module: P/N 28100-P8A-003

SPECIAL TOOLS REQUIRED

16/16 Pin DLC Adapter (red): T/N P25132

16/14 Pin OBD II Type 3 Adapter: T/N 02001969

NOTE:
Adapters can be ordered by calling Special Tools at 1-800-346-6327.

WARRANTY CLAIM INFORMATION

In warranty:
The normal warranty applies.

Operation number: 218113

Flat rate time: 0.3 hr

Failed P/N: 28100-P8A-003

Defect code: 072

Contention code: B03

Template ID: 97-011A

Out of warranty:
Any repair performed after warranty expiration may be eligible for goodwill consideration by the District Technical Manager or your Zone Office. You must request consideration, and get a decision, before starting work.