What it means
The output stage for the clutch A BLDC motor reports a high phase voltage on at least one of the U/V/W phases. Short to B+ or interrupted load.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
The clutch A BLDC motor uses U, V, and W phases, switched by an output stage, to move the clutch actuator. This code sets when the output stage detects that at least one phase voltage is too high, which can indicate a phase wire shorted to battery voltage, an open motor winding, or a poor connection.
Common causes
Most likely first.
- Phase wire shorted to B+
- Open motor winding
- Connector pins corroded - high contact resistance
Symptoms
- Check engine or transmission warning light on
- Harsh, delayed, or missing shifts
- Possible limp mode (locked in one gear)
- Slipping or shuddering during gear changes
How to diagnose it
- Review transmission freeze-frame data and live clutch A commands and phase readings to identify when the high-phase fault occurs.
- Inspect the U, V, and W phase wiring and connectors for corrosion, loose pins, damage, or contact with a battery-voltage wire.
- Check the phase circuits for shorts to battery voltage using the wiring diagram and the manufacturer's isolation procedure.
- With the motor isolated as prescribed, check for an open winding and compare the result with the manufacturer's specification.
- If wiring and winding checks pass, test the clutch A output stage using the manufacturer's diagnostic procedure.
Common fixes
- Repair a U, V, or W phase wire shorted to battery voltage.
- Clean and secure corroded or loose clutch A phase connector terminals.
- Replace the clutch A motor if testing confirms an open winding.
- Repair or replace the output stage if its operation is confirmed faulty.
Can I keep driving?
Avoid driving if shifting is harsh, delayed, slipping, or the vehicle enters limp mode; arrange recovery if it cannot select gears reliably. Continued operation can worsen clutch or transmission damage.
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.