What it means
The signals of the HV battery voltage and drive motor A inverter voltage do not correlate within the calibrated tolerance.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
The control system compares high-voltage battery voltage with the voltage reported by the drive motor A inverter to check that the two readings agree as expected. This code sets when the battery and motor A inverter signals diverge beyond the calibrated tolerance, which may reflect sensor drift, a difference in their ground references, or an imbalance within the battery pack.
Common causes
Most likely first.
- One sensor characteristic drifted
- Ground offset between channels
- Pack cell imbalance approaching service threshold
Symptoms
- EV/hybrid system warning light on
- Reduced power output or limp mode
- Charging may fail or be slowed
- Reduced electric range
How to diagnose it
- Save freeze-frame data and compare live battery voltage with drive motor A inverter voltage under the conditions that set the fault.
- Check related voltage readings and charging status for patterns that point to a sensor mismatch or changing battery-pack imbalance.
- With the vehicle powered down as specified by the manufacturer, inspect accessible low-voltage connectors and grounds for the battery voltage measurement and motor A inverter sensor circuits.
- Use the wiring diagram to test the two signal paths and ground references for poor connections or voltage offset.
- If the circuits pass, have the battery management data assessed for cell-group imbalance and compare each voltage sensor with the manufacturer’s specification.
Common fixes
- Repair a loose or corroded connection in the battery or motor A inverter voltage sensing circuits.
- Correct a poor ground connection causing an offset between the voltage channels.
- Replace the voltage sensor that fails its specified accuracy check.
- Service the battery pack if cell-group imbalance is confirmed.
Can I keep driving?
Limit driving if power is reduced, charging is restricted, or the warning persists, since the vehicle may enter limp mode. Reduced electric range or charging problems can worsen, and the vehicle may limit propulsion to protect the high-voltage system.
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.