DTC U0146
DTC U0146: Lost Communication With CAN Gateway
General Description
The controller area network (CAN) transmits/receives pulsing signals to/from the control modules simultaneously by using F-CAN A and B signal lines. If the transmission control module (TCM) cannot receive the signal sent from the CAN gateway for a specified time, or if the received signal is abnormal for a specified duration, the TCM 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, A/T gear position indicator blinks |
Enable Conditions
| Condition | Minimum | Maximum |
|---|---|---|
| 12 volt battery voltage [Battery Voltage] | 9 V | 16 V |
| Vehicle | ON mode | |
[ ]: HDS Parameter
Malfunction Threshold
Either of the conditions is met:
- The TCM cannot receive the signal sent from the CAN gateway at least 3 times.
- The TCM receives abnormal signal from the CAN gateway for at least 1 second.
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.
- TCM F-CAN A_H line open
- TCM F-CAN A_L line open
- TCM F-CAN B_H line open
- TCM F-CAN B_L line open
- TCM internal failure
Diagnosis Details
Conditions for setting the DTC
When a malfunction is detected, the A/T gear position indicator blinks, the MIL comes on, and a Pending DTC, a Confirmed DTC, and the freeze data are stored in the TCM memory.
Conditions for clearing the DTC
The A/T gear position indicator comes off by turning the vehicle to the OFF (LOCK) mode. 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.