U0100 LOST COMMUNICATION WITH ECM/PCM

For a complete wiring diagram Refer to Section 8W.

Theory of Operation


The NGC 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.


(Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - DIAGNOSIS AND TESTING) for diagnostic procedures and for further possible causes.