Possible Causes
| Possible Causes |
|---|
| CAN BUS CIRCUIT DTC PRESENT |
| TRANSMISSION CONTROL MODULE (TCM) |
| POWERTRAIN / ENGINE CONTROL MODULE (PCM OR ECM) |
Always perform the NAG1 Pre-Diagnostic Troubleshooting procedure before proceeding. Refer to NAG1 PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .