Advanced Diagnostics

Advanced Diagnostics - DTC U0155: F-CAN Malfunction (Engine Control Module (ECM)/Powertrain Control Module (PCM)-Gauge Control 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 the gauge control module via the F-CAN lines and this condition continues for a specified time or when the information sent from the gauge control module is abnormal and this condition continues for a specified cycle, the engine control module (ECM)/powertrain control module (PCM) detects a malfunction and stores a DTC.

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






Enable Conditions






Malfunction Threshold
One of these conditions must be met:
- The ECM/PCM does not receive any signals via the F-CAN lines for at least 1 second.
- The information sent from the gauge control module is abnormal at least 20 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 ECM/PCM 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.