P1629-TCM INTERNAL - SOLENOID SUPPLY/ WATCHDOG

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. During the power up of the controller, the TCM tests the ability of the TCM to shut down the Solenoid Supply Voltage circuit. The controller monitors the A/D feedback on the Solenoid Supply driver output to ensure that battery voltage is no longer present. Note: A short to voltage on the Solenoid Supply Voltage circuit or any one of the solenoids may set this DTC.

• When Monitored:

  Continuously with the ignition on.

• Set Condition:

  If the TCM detects voltage on the Solenoid Supply Voltage circuit when the TCM request the circuit to be off.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - NAG1 - STANDARD PROCEDURE)

Diagnostic Test

• Repair the (T78) Solenoid Supply Voltage circuit for short to another circuit.
• Perform NAG1 TRANSMISSION VERIFICATION TEST. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - NAG1 - STANDARD PROCEDURE)

• 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)