What it means
The hybrid control module detects a generic fault on phase Y current measurement of drive motor A. The drive motor's position, current and temperature are watched continuously; a fault here downgrades the inverter to a safe operating point or triggers torque reduction.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
Drive motor A uses three phase-current measurements to control inverter output and monitor torque. The hybrid control module flags this code when the phase Y measurement has a general fault, rather than a specifically detected low or high reading; it may limit motor torque to protect the inverter.
Common causes
Most likely first.
- Phase current sensor failed
- Wiring or connector fault
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 check hybrid-system live data for drive motor A phase Y current, then compare it with phases X and Z under the same operating conditions.
- Check for related inverter, motor, or hybrid-system codes that could explain why the phase Y reading is implausible.
- With the vehicle powered down according to the manufacturer's safety procedure, inspect the phase Y sensor wiring and connectors for damage, corrosion, looseness, or moisture.
- Check the phase Y current sensor supply, ground, signal wiring, and connector continuity using the manufacturer's procedure.
- If the wiring checks pass, have the phase Y sensor and inverter measurement circuit tested against the manufacturer's specification.
Common fixes
- Secure or clean a loose or corroded phase Y sensor connector.
- Repair damaged phase Y sensor wiring.
- Replace a failed phase Y current sensor if it is serviceable separately.
- Repair or replace the inverter if its phase Y measurement circuit has failed.
Can I keep driving?
Avoid hard acceleration and relying on electric drive, since torque may be limited or the vehicle may enter limp mode or shut down. If the hybrid warning is accompanied by a sudden loss of power or a temperature warning, stop safely and arrange inspection.
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.