What does code U353A mean?

Q: What does code U353A mean?

High Voltage System Interlock Circuit M Performance. The high voltage system interlock circuit is a low-voltage safety loop that runs through every high-voltage connector, service disconnect and cover on a hybrid or electric vehicle, and it must remain continuous for the vehicle to allow high voltage to flow. Code U353A means the control module monitoring that loop has detected a performance fault on the 'M' segment of the interlock circuit, typically a voltage reading outside the expected range rather than a simple open circuit. The module sets the code when the interlock signal on that specific branch does not behave as designed, which usually forces the high-voltage system to shut down or refuse to start.

DTC codes / U35xx · Network communication / U353A

U353AHigh Voltage System Interlock Circuit M Performance

The high voltage system interlock circuit is a low-voltage safety loop that runs through every high-voltage connector, service disconnect and cover on a hybrid or electric vehicle, and it must remain continuous for the vehicle to allow high voltage to flow. Code U353A means the control module monitoring that loop has detected a performance fault on the 'M' segment of the interlock circuit, typically a voltage reading outside the expected range rather than a simple open circuit. The module sets the code when the interlock signal on that specific branch does not behave as designed, which usually forces the high-voltage system to shut down or refuse to start.

SystemNetwork

Code typeGeneric (all makes)

SeverityHigh

Fix difficultyProfessional

AreaNetwork communication

Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.