Transmission Control Module (TCM) - NAG1

U0100-LOST COMMUNICATION WITH ECM/PCM

For a complete wiring diagram, refer to the Wiring Information.

Theory of Operation

The GPEC controller communicates over the CAN C BUS. The transmission controller continuously monitors BUS activity. The CAN C BUS is also used to communicate transmission MIL status to the Engine Controller. If the Engine Controller is unable to communicate with the Transmission Controller, a DTC will set and the Engine Controller will illuminate the MIL.

- When Monitored:
Every 7 msec with:

1) Engine speed greater than 500 rpm.

2) Battery voltage between 10 and 16 volts.

- Set Condition:
CAN C BUS messages are not received for 10 seconds.

for CAN BUS Communication diagnostic procedures and other possible causes. Testing and Inspection