DTC U0029-00 (CAN Gateway)
DTC U0029-00: CAN Gateway F-CAN ch A Bus Off
General Description
The CAN gateway performs self-diagnosis to detect the state where the CAN frame cannot be sent due to failure in the F-CAN line. If the bus-off occurs due to open and short circuit in the F-CAN line is detected for a prescribed time, the CAN gateway detects a malfunction and stores a DTC.
Monitor Execution, Sequence, Duration, DTC Type
| Execution | Continuous |
| Sequence | None |
| Duration | 6 seconds or more |
| DTC Type | One drive cycle, MIL on or off (CAN gateway does not output MIL on/off request) |
Enable Conditions
| Condition | Minimum | Maximum |
|---|---|---|
| Elapsed time since the 12 volt battery voltage reaches to a specified value after the vehicle condition is turned to the ON mode | 5 seconds | - |
| 12 volt battery voltage [ Battery ] | 10 V | - |
| [ ] : HDS Parameter | ||
Malfunction Threshold
One of these conditions is met:
- The F-CAN A line bus-off continues for at least 6 seconds.
- The CAN frame transmission to the F-CAN A line does not complete within 6 seconds.
Possible Cause
The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
- CAN gateway F-CAN A_H line open (include connector loose connection or disconnection)
- CAN gateway F-CAN A_L line open (include connector loose connection or disconnection)
- CAN gateway F-CAN A_H line short to CAN gateway F-CAN A_L line
- CAN gateway F-CAN A_H line short to ground
- CAN gateway F-CAN A_L line short to ground
- CAN gateway internal circuit short
- Unit communicating on F-CAN A failure
Diagnosis Details
Conditions for setting the DTC
When a malfunction is detected, a DTC, the freeze data, and the on-board snapshot are stored in the CAN gateway memory.
Conditions for clearing the DTC
The DTC, the freeze data, and the on-board snapshot can be cleared with the scan tool Clear command.