Drivetrain Control Module (DTCM)

U0121-LOST COMMUNICATION WITH ABS





For a complete wiring diagram, consult the Wiring Information.

Theory of Operation

The ABS communicates with other controllers over the CAN C bus. The DTCM Module continuously monitors the bus activity and receives the messages it needs. If the DTCM does not receive messages from the ABS Module , then this fault will set and the service 4WD is illuminated.

- When Monitored:
With the ignition on.

Battery voltage between 10 and 16 volts.

Ignition Off Draw (IOD) fuse installed.

Totally Integrated Power Module (TIPM) is configured correctly.

- Set Condition:
Bus messages not received from the Antilock Brake Module for approximately two to five seconds.





VERIFY DTC IS ACTIVE
1. Ignition on, engine not running.
2. With a scan tool, read DTCs.

Is the DTC Active at this time?

Yes

- Perform the appropriate diagnostic procedure. . Totally Integrated Power Module (TIPM)

No

- Perform the INTERMITTENT CONDITION diagnostic procedure. ABS Intermittent Condition Test.