DTC U0029
DTC U0029: F-CAN Malfunction (BUS-OFF (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 (H line and L line). When the powertrain control module (PCM) cannot send the signals via the F-CAN lines for a set time, the PCM detects a malfunction and stores a DTC.
Monitor Execution, Sequence, Duration, DTC Type
| Execution | Continuous |
| Sequence | None |
| Duration | 1 second or more |
| DTC Type | One drive cycle, MIL on |
Enable Conditions
| Condition | Minimum | Maximum |
|---|---|---|
| Elapsed time after the vehicle condition is turned to the ON mode | 3 seconds | - |
| 12 volt battery voltage [BATTERY] | 10.0 V | - |
[ ]: HDS Parameter
Malfunction Threshold
The PCM cannot send any signals via the F-CAN lines for at least 1 second.
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.
- F-CAN circuit F-CAN_H* 1 (F-CAN A_H)* 2 line open
- F-CAN circuit F-CAN_L* 1 (F-CAN A_L)* 2 line open
- F-CAN circuit F-CAN_H* 1 (F-CAN A_H)* 2 line short to ground
- F-CAN circuit F-CAN_L* 1 (F-CAN A_L)* 2 line short to ground
- PCM internal circuit failure
*1: Without CAN gateway (6-Speed A/T)*2: With CAN gateway (6-Speed A/T), 9-Speed A/T
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 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 12 volt battery.