Intermittent

SYMPTOM
U0121 - LOST COMMUNICATION WITH ANTILOCK BRAKE MODULE

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

POSSIBLE CAUSES
- CAN C BUS FAILURE OPEN OR SHORTED CONDITION
- ABS MODULE
- PCM

DIAGNOSTIC TEST
1. ACTIVE DTC





Ignition on, engine not running.
With a scan tool, read PCM DTCs.
Is the DTC active at this time?
Yes>> Refer to ELECTRICAL/ELECTRONIC CONTROL MODULES - DIAGNOSIS AND TESTING for diagnostic procedures and for further possible causes.
No>> Perform (NGC) POWERTRAIN VERIFICATION TEST VER-5. Powertrain Verification Test - Ver 5