U0121

U0121-00-LOST COMMUNICATION WITH ANTI-LOCK BRAKE SYSTEM (ABS) CONTROL MODULE

For a complete wiring diagram, refer to the Wiring Information.

- When Monitored:
With the ignition on for at least five seconds.

Battery voltage between 10 and 16 volts.

- Set Condition:
Bus messages not received from the Anti-lock Brake System Module (ABS) for approximately two to five seconds.





Diagnostic Test
CHECK FOR AN ACTIVE DTC

NOTE: If DTC U0002-00-CAN C BUS OFF PERFORMANCE is set in the Body Control Module (BCM), diagnose this DTC before continuing with this diagnostic procedure.

1. Turn the ignition on.
2. With the scan tool, read active DTCs.

Does the scan tool display this DTC as active?

Yes

- Manufacturer Code Charts and perform the NO RESPONSE FROM ABS (ANTI-LOCK BRAKE SYSTEM MODULE) diagnostic procedure.

No

- Manufacturer Code Charts and perform the STORED LOST COMMUNICATION DTCS diagnostic procedure.