What it means
The drive motor A excitation current sensor circuit reports a generic fault. Field excitation current measurement is unreliable.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
The drive motor A excitation-current sensor measures current used to create the motor's magnetic field. The control module relies on that measurement to control motor output; this code sets when the sensor circuit has a fault and the field-current reading cannot be trusted.
Common causes
Most likely first.
- Excitation current sensor failed
- Wiring fault
Symptoms
- EV/hybrid system warning light on
- Reduced motor power or torque
- Possible limp mode or vehicle shutdown
How to diagnose it
- Use a scan tool to save freeze-frame data and review drive motor A excitation-current readings and related hybrid-system faults.
- With the vehicle safely powered down according to its service instructions, inspect the accessible motor A sensor harness and connectors for damage, looseness, or corrosion.
- Compare the excitation-current reading with commanded motor operation to see whether it is missing, fixed, or implausible.
- Using the manufacturer's wiring diagram and safety procedure, test the excitation-current sensor circuit for continuity, shorts, and connector contact faults.
- If wiring passes, test the drive motor A excitation-current sensor against the manufacturer's specification.
Common fixes
- Secure or clean a loose or corroded sensor connector where serviceable.
- Repair damaged wiring in the drive motor A excitation-current sensor circuit.
- Replace the excitation-current sensor if it fails the manufacturer's checks.
Can I keep driving?
Reduced motor torque, limp mode, or shutdown may occur, so avoid relying on the vehicle for a long or demanding trip. If the vehicle loses power or displays a hybrid-system warning that affects drivability, stop safely 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.