Advanced Diagnostics

Advanced Diagnostics - DTC U0155: F-CAN Malfunction (Engine Control Module (ECM)-Gauge Control Module) (Engine Type: K24Z7)

General Description






The controller area network (CAN) transmits/receives pulsing signals to/from the control modules simultaneously by using two signal lines (F_CAN-H and F_CAN-L). When the information is not sent from the gauge control module (tach) via the F-CAN lines and this condition continues for a specified time or when the information sent from the gauge control module (tach) is abnormal and this condition continues for a specified cycle, the engine control module (ECM) detects a malfunction and stores a DTC.

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






Enable Conditions






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

Possible Cause

NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.

- Gauge control module (tach) (include fuse fall-outs)
- F-CAN circuit F_CAN-H line open
- F-CAN circuit F_CAN-L line open
- F-CAN circuit F_CAN-H line short to ground
- F-CAN circuit F_CAN-L line short to ground
- ECM internal circuit failure

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 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.