Advanced Diagnostics
DTC U0122: F-CAN Malfunction (Engine Control Module (ECM)/Powertrain Control Module (PCM)-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 more than a set time, the ECM/PCM detects a malfunction and a DTC is stored.
Monitor Execution, Sequence, Duration, DTC Type, OBD Status
Enable Conditions
Malfunction Threshold
The ECM/PCM does not receive any signals 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.