545RFE Automatic Transmission

U0121-LOST COMMUNICATION WITH ABS

For a complete wiring diagram Consult Diagrams/Electrical.

Theory of Operation

Some NGC controllers communicate with other controllers over the CAN C bus. The transmission controller continuously monitors the bus activity and receives the messages it needs. The CAN C bus is also used to communicate transmission MIL status to the Engine Controller, therefor if the Engine Controller is unable to communicate with the Transmission Controller, the Engine Controller will light the MIL.

- When Monitored:
Every 7 msec. Conditions:

1) Engine speed greater than 500 rpm.

2) Battery voltage greater than 10.0 volts but less than 16.0 volts.

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

Refer to appropriate diagnostic procedures for further possible causes.