For 1990-2009 cars only
Service 4WD Light On, 4WD Inoperative, Diagnostic Trouble Codes (DTC) C0300 and/or C0305 Set (Reprogram Transfer Case Control Module (TCCM))
| Subject: | Service 4WD Light On, 4WD Inoperative, Diagnostic Trouble Codes (DTC) C0300 and/or C0305 Set (Reprogram Transfer Case Control Module (TCCM)) |
| Models: | 2003 Chevrolet Avalanche, Silverado, Suburban, Tahoe, TrailBlazer |
| 2003 GMC Envoy, Sierra, Yukon, Yukon XL |
| 2003 Oldsmobile Bravada |
| with 4WD (RPOs NP4, NP8) |
Condition
Some customers may comment that the Service 4WD light is on and/or the 4WD is inoperative.
Cause
Condition may be caused by a TCCM calibration issue.
Correction
Follow the service procedure below for diagnosis and repair of this condition.
- With a scan tool, select the TCCM DTCs.
- Clear all DTCs and reprogram the TCCM with TIS version 3.5 or newer released to the dealers on 3-22-03. Refer to Transfer Case Control Module Reprogramming (SI Document ID #727487).
| • | If TCCM DTCs C0300 or C0305 are present in the TCCM, continue with TCCM reprogramming in Step 2. |
| • | If TCCM DTC C0374 is present with any of the above codes, disregard and clear the DTC and continue with TCCM reprogramming in step 2. |
| • | If TCCM DTC C0374 is present alone with none of the above listed codes, additional diagnosis is required. Refer to Service Information (SI) for proper diagnosis of the applicable vehicle. |
| • | If TCCM DTC C0550 is present, refer to DTC C0550 in SI for proper diagnosis of the applicable vehicle. |
Warranty Information
For vehicles repaired under warranty, use:
Labor Operation | Description | Labor Time |
|---|---|---|
N8521 | Module, Transfer Case Control - Reprogram | 0.4 hr |
Add: | Diagnosis | 0.0-0.3 hr |
