ECM/ PCM

Advanced Diagnostics

DTC U0029: F-CAN Malfunction (BUS-OFF (Engine Control Module (ECM)/ Powertrain Control Module (PCM)))







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 via the CAN lines are received for at least 1 second.

Diagnosis Details

Conditions for illuminating the MIL
When a malfunction is detected, the MIL comes on and the DTC and the freeze frame data are stored in the ECM/PCM memory.

Conditions for clearing the MIL
The MIL will be cleared if the malfunction does not recur during three consecutive trips in which the diagnostic runs. The MIL, the DTC, and the freeze frame data can be cleared by using the scan tool Clear command or by disconnecting the battery.