P1637-TCM INTERNAL-EEPROM PERFORMANCE
For a complete wiring diagram Refer to Section 8W
Theory of Operation
The Transmission Control Module (TCM) performs various internal tests to verify proper controller operation. This DTC indicates that there is an internal error with the controllers Random Access Memory. If detected, the controller will enter Limp-in mode and illuminate the MIL.
- When Monitored:
Continuously with the ignition on.
- Set Condition:
If the TCM indicates that there is an internal error with the controllers Random Access Memory.
| Possible Causes |
| TRANSMISSION CONTROL MODULE |
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - NAG1 - STANDARD PROCEDURE)
Diagnostic Test
1. TRANSMISSION CONTROL MODULEView repair
Repair
- Using the schematics as a guide, check the Transmission Control Module (TCM) pins, terminals, and connectors for corrosion, damage, or terminal push out. Pay particular attention to all power and ground circuits. If no problems are found, replace the TCM per the Service Information. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES/TRANSMISSION CONTROL MODULE - REMOVAL)
- Perform NAG1 TRANSMISSION VERIFICATION TEST. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - NAG1 - STANDARD PROCEDURE)