What it means
The ECM detects a high fault on the drive motor b inverter voltage sensor a circuit. Reading cannot be used reliably for control.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
The drive motor B inverter voltage sensor A reports an inverter voltage signal that the control module monitors for plausible operation. This code sets when the signal is higher than its acceptable range, such as when the signal wire is pulled toward battery voltage or the sensor circuit is open.
Common causes
Most likely first.
- Signal wire shorted to B+
- Open sensor
- Connector pins corroded - high contact resistance
Symptoms
- EV/hybrid system warning light on
- Reduced motor power or torque
- Possible limp mode or vehicle shutdown
How to diagnose it
- Save freeze-frame data and compare sensor A’s live reading with related inverter and battery voltage readings to verify the high signal.
- With the vehicle powered down as specified by the manufacturer, inspect sensor A’s connector for corrosion, loose pins, or an open connection.
- Inspect the signal wire from the motor B inverter sensor for damage or contact with a power feed.
- Use the wiring diagram to check the signal circuit for a short to B+ and test for an open in the sensor circuit.
- If wiring and connections are intact, test sensor A against the manufacturer’s specification for an open or failed output.
Common fixes
- Reconnect or repair a loose or open sensor A connector connection.
- Repair the signal wire if it is shorted to B+.
- Restore continuity in an open sensor circuit.
- Replace sensor A if it is internally open or fails the specified test.
Can I keep driving?
Avoid unnecessary trips because the control system may limit motor power, enter limp mode, or shut the vehicle down. Stop safely if propulsion is reduced or unpredictable and arrange prompt diagnosis.
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.