Advanced Diagnostics

Advanced Diagnostics

DTC U0122: F-CAN Malfunction (Engine Control Module (ECM)/Powertrain Control Module-VSA Modulator-Control Unit)






General Description
The controller area network (CAN) transmits/receives pulsing signals to/from the control modules simultaneously by using two signal lines (CANH and CANL). When the engine control module (ECM)/powertrain control module (PCM) does not receive the signals via the CAN lines for a set time or more, the ECM/PCM detects a malfunction and a DTC is stored.

Monitor Execution, Sequence, Duration, DTC Type, OBD Status






Enable Conditions






Malfunction Threshold
No signals from the VSA modulator-control unit via the CAN lines are received for at least 1 second.

Diagnosis Details

Conditions for illuminating the indicator
When a malfunction is detected, the DTC and the freeze frame data are stored in the ECM/PCM memory. The MIL does not come on.

Conditions for clearing the DTC
The DTC and the freeze frame data can be cleared by using the scan tool Clear command or by disconnecting the battery.