Diagnostic Aids

DTC U0121:00 indicates that the ABS module cannot communicate over the HS-CAN bus. This could be due to a DTC being set in the ABS or a circuit fault in the HS-CAN bus. Do not install a new PSCM as part of the repair for a PSCM DTC U0121:00.

The presence of DTC U0121:00 will prevent the active park assist system and lane keep assist function (if equipped) from activating. If set during an active park assist event, the event will be terminated and the active park assist system will deactivate. The driver may also experience the vehicle pulling to the left or right during acceleration.