40/41TE Automatic Transaxle (GPEC)

U0121 LOST COMMUNICATION WITH ABS

For a complete wiring diagram Consult Diagrams/Electrical.

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.

Refer to Communications Test for this DTC and/or Manufacturer Code Charts for diagnostic procedures and for further possible causes.