DTC U129E
DTC U129E: Lost Communication with PCU
General Description
Without CAN gateway
With CAN gateway
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 keyless access/TPMS control unit 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 off, 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 keyless access/TPMS control unit at least 3 times.
- The TCM receives abnormal signal from the keyless access/TPMS control unit 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.
- F-CAN circuit F-CAN A_H* 1 (F-CAN B_H)* 2 line open
- F-CAN circuit F-CAN A_L* 1 (F-CAN B_L)* 2 line open
- Keyless access/TPMS control unit internal failure
- TCM internal failure
*1: Without CAN gateway*2: With CAN gateway
Diagnosis Details
Conditions for setting the DTC
When a malfunction is detected, the A/T gear position indicator blinks and a Pending DTC, a Confirmed DTC, and the freeze data are stored in the TCM memory. The MIL does not come on.
Conditions for clearing the DTC
The A/T gear position indicator comes off by turning the vehicle to the OFF (LOCK) mode. The Pending DTC, the Confirmed DTC, and the freeze data can be cleared with the scan tool Clear command.