Possible Causes
| Possible Causes |
|---|
| ENGINE BRAKE DTCS PRESENT |
| WIN DTCS PRESENT |
| (K321) BTSI CONTROL CIRCUIT SHORT TO VOLTAGE |
| ELECTRONIC SHIFT MODULE (ESM) |
Always perform the NAG1 Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to DTC-Based Diagnostics/MODULE, Transmission Control (TCM) - Standard Procedure .