IMA System (BCM)

Advanced Diagnostics - DTC U0028 (108): F-CAN Malfunction (BUS-OFF (Battery Condition Monitor BCM) Module))






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 information is not sent from all nodes through the F-CAN and this condition continues for a specified time or when the information sent from all nodes is abnormal and this condition continues for a specified cycle, the battery condition monitor (BCM) module detects a malfunction and stores a DTC.

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






Enable Conditions






Malfunction Threshold
The following conditions occur at the same time within 2 seconds:
- The information sent from the motor control module (MCM) through the F-CAN is not received for at least 0.5 second or the information sent from the MCM through the F-CAN is abnormal at least 10 times.
- The information sent from the powertrain control module (PCM) through the F-CAN is not received for at least 0.5 second or the information sent from the PCM through the F-CAN is abnormal at least 10 times.
- The information sent from the gauge control module through the F-CAN is not received for at least 1 second or the information sent from the gauge control module through the F-CAN is abnormal at least 10 times.

Diagnosis Details

Conditions for setting the DTC
When a malfunction is detected, the MIL comes on and a Pending DTC, a Confirmed DTC, and the freeze data are stored in the PCM and the BCM module memory.

Conditions for clearing the DTC
The MIL is cleared if the malfunction does not return in three consecutive trips in which the diagnostic runs. The MIL, the Pending DTC, the Confirmed DTC, and the freeze data can be cleared with the scan tool Clear command or by disconnecting the battery.