DTC U0101-00 (VSA Control Unit)
DTC U0101-00
: CAN Communication Failure With PCM/TCM
NOTE
- Initial Diagnosis:
The initial on-board diagnosis occurs right after the vehicle condition is turned to the ON mode, and the ABS, VSA, and brake system indicator (amber) come on, and continues until the indicator goes off.
- Regular Diagnosis:
The regular on-board diagnosis begins right after the ABS, VSA, and brake system indicator (amber) go off, and it continues until the vehicle condition is turned to the OFF (LOCK) mode.
- Review "How to Troubleshoot the VSA System" before doing the DTC troubleshooting procedure.
- Test-drive the vehicle according to local traffic conditions and regulations. Do not test-drive on a lift unless specified.
- The possible causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
| Confirmation Procedure |
Basic Condition:
- 12 volt battery voltage 10 V or more
Operating Condition:
- Start the engine.
- Test-drive the vehicle at 7 mph (10 km/h) or more for at least 2 seconds.(Drive the vehicle on the road, not on a lift. Be careful of the surrounding traffic conditions.)
|
| Execution |
Regular Diagnosis |
| Duration |
About 2 seconds |
| DTC Type |
- 1 drive cycle
- Brake system indicator (amber) on
- VSA indicator on
|
| Fail Safe Action |
- Stop engine drag torque control function
- Stop TCS function
- Stop VSA function
- Stop agile handling assist function
- Stop hill start assist function
- Stop automatic brake hold control function
- Stop starting assist brake function (dependant upon the conditions)* 1
- Stop ACC function (dependant upon the conditions)* 2
- Stop CMBS function (dependant upon the conditions)* 2
- Stop drive away assist function
- Stop parking cooperation assist function* 3
|
| Possible Cause |
- Open between the VSA modulator-control unit and the TCM (F-CAN A_H, F-CAN A_L, F-CAN B_H, F-CAN B_L lines)* 4
- Open between the VSA modulator-control unit and the CAN gateway (F-CAN A_H, F-CAN A_L lines)* 2* 5
- Open between the CAN gateway and the TCM (F-CAN A_H, F-CAN A_L lines)* 2* 5
- Open between the VSA modulator-control unit and the TCM (F-CAN B_H, F-CAN B_L lines)* 2* 5
- Open between the VSA modulator-control unit and the CAN gateway (F-CAN A_H, F-CAN A_L, F-CAN B_H, F-CAN B_L lines)* 2* 6
- Open between the CAN gateway and the TCM (F-CAN A_H, F-CAN A_L, F-CAN B_H, F-CAN B_L lines)* 2* 6
- TCM internal failure
- VSA modulator-control unit internal failure
|
*1: With auto idle stop system
*2: With ACC
*3: 9-speed A/T
*4: Without ACC
*5: 2018-20
*6: 2021-23