Operation CHARM: Car repair manuals for everyone.

6.7L Diesel






U0121-LOST COMMUNICATION WITH ANTI-LOCK BRAKE MODULE

For complete wiring diagrams refer to Diagrams/Electrical.


- When Monitored:

Ignition run time is greater than 1 second. Battery voltage between 9 and 16 volts. Engine run time greater than 3 seconds.

- Set Condition:

The ECM doesn't receive an ABS message over the CAN C circuit for 7 consecutive seconds. The circuit is continuously monitored. One Trip fault.







Refer to Communications for diagnostic procedures and for further possible causes.

Diagnostic Test


1. ACTIVE DTC

Ignition on, engine not running.

With a scan tool, read ECM DTCs.

Is the DTC active at this time?

Yes

- Refer to Communications for diagnostic procedures and for further possible causes.

No

- Refer to the INTERMITTENT CONDITION Diagnostic Procedure. Intermittent Condition