DTC Advanced Diagnostics: U0104-00
DTC U0104-00: CAN Communication Failure with Driving Support System Control Unit
NOTE
Initial Diagnosis:
The initial on-board diagnosis occurs right after the vehicle condition is turned to the ON mode, and the ABS/VSA indicator comes on, and continues until the indicator goes off.
Regular Diagnosis:
The regular on-board diagnosis begins right after the ABS/VSA indicator goes 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 9.6 - 16.5 V

With the Driving Pattern:
1.
Start the engine.
Execution
Regular Diagnosis
Duration
About 1 second
DTC Type
1 drive cycle
Fail Safe Action
Stop ACC function
Stop CMBS function
Possible Cause
Open or Poor connection between the VSA modulator-control unit and the millimeter wave radar (F-CAN lines)
Millimeter wave radar internal failure
VSA modulator-control unit internal failure