What it means
The control circuit for drive motor A inverter voltage sensor B has a detected fault. The module sets this code when the sensor circuit fails its electrical monitoring checks.
How it works
Drive motor A's inverter voltage sensor B monitors a voltage within the inverter that converts power for the motor. This code sets when the sensor B control circuit fails the module's electrical checks, so the module cannot trust that voltage signal.
Common causes
Most likely first.
- Failed inverter voltage sensor
- Open or shorted wiring
- Loose or corroded connector
- Inverter or control module fault
Symptoms
- Hybrid or EV warning light
- Reduced power
- Vehicle may not enter READY mode
- Reduced or unavailable regenerative braking
How to diagnose it
- Scan the hybrid or EV control modules for freeze-frame data and related inverter codes, noting whether the vehicle failed to enter READY or lost regenerative braking.
- With the high-voltage system made safe using the manufacturer's procedure, inspect sensor B's connector and accessible wiring at drive motor A's inverter for loose, corroded, damaged, or pinched sections.
- Check the sensor B circuit for an open or short using the wiring diagram and compare continuity and isolation results with the manufacturer's specification.
- Verify the circuit's supply and ground where specified, checking for poor connector contact or a missing reference that could trigger an electrical fault.
- If the wiring and connections pass, test drive motor A inverter voltage sensor B and the inverter or control module according to manufacturer procedures before replacing a component.
Common fixes
- Reseat or clean the drive motor A inverter sensor B connector.
- Repair an open or short in the sensor B wiring.
- Replace the failed drive motor A inverter voltage sensor B if its circuit tests pass.
- Repair or replace the inverter or control module only if its checks identify an internal fault.
Can I keep driving?
Reduced power, unavailable regenerative braking, or failure to enter READY can leave the vehicle unable to operate normally. Avoid driving if the vehicle will not enter READY or power is limited; inverter circuits involve hazardous high voltage, so have the fault checked using the manufacturer's safety procedure.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.