What it means
The ECM detects a low fault on the drive motor a inverter voltage sensor b 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
Drive motor B's inverter voltage sensor B monitors an inverter voltage used by the control module to manage motor operation. This code sets when the sensor B circuit has an electrical fault; the title identifies the circuit condition, while the supplied meaning and causes do not specify whether the signal is low, high, or open.
Common causes
Most likely first.
- Signal wire shorted to ground
- Internal sensor short
- 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
- Scan for freeze-frame data and related inverter codes, and confirm that the affected circuit is drive motor B inverter voltage sensor B rather than the corresponding sensor on motor A.
- With the high-voltage system made safe, inspect drive motor B inverter sensor B's connector and wiring for corrosion, loose pins, damage, or a poor ground contact.
- Use the wiring diagram to check the sensor B circuit for an open or short and compare continuity and isolation results with the manufacturer's specification.
- Check the sensor's ground and reference connections where specified, paying particular attention to high contact resistance at corroded terminals.
- If the circuit tests correctly, test drive motor B inverter voltage sensor B and the inverter or control module for an internal electrical fault.
Common fixes
- Clean, reseat, or repair corroded contacts at drive motor B sensor B's connector.
- Repair an open, short, or poor ground connection in the sensor B circuit.
- Replace drive motor B inverter voltage sensor B if its electrical test fails.
- Repair the inverter or control module only if its specified checks confirm an internal fault.
Can I keep driving?
The warning may be accompanied by reduced motor torque, limp operation, or inability to enter READY. Avoid driving if power is limited or unstable; inverter circuits carry hazardous high voltage and require safe service procedures.
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.