P0C07: Drive Motor A Phase U-V-W Circuit High

What it means

The drive motor A phase U-V-W output reports a circuit high condition. 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 receives controlled power through the inverter's U, V, and W phase outputs. P0C07 sets when the module detects an abnormally high phase output condition, which can be caused by a phase wire shorted to high voltage, an open motor winding, or a poor connector contact.

Common causes

Most likely first.

1. Phase wire shorted to high voltage
2. Open motor winding
3. 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

1. Check freeze-frame and live hybrid data for Drive Motor A phase readings, current, torque request, and other inverter codes to establish when the high condition occurs.
2. With the high-voltage system safely disabled under the manufacturer's procedure, inspect the Drive Motor A U, V, and W connectors and harness for damaged insulation, loose pins, or heat damage.
3. Check whether the phase wiring is shorted to a high-voltage source using the manufacturer's isolation and measurement procedure.
4. Have a qualified technician test the Drive Motor A windings for an open and inspect connector contact condition against the manufacturer's diagnostic guidance.
5. If the motor and harness check out, test the inverter phase output for a control fault.

Common fixes

• Repair phase wiring with damaged insulation or a short to high voltage.
• Repair a loose, corroded, or heat-damaged phase connector.
• Repair or replace the motor if an open winding is confirmed.
• Repair or replace the inverter if its phase output is confirmed faulty.

Can I keep driving?

Do not demand high power from the vehicle, as Drive Motor A may lose torque and the system may enter limp mode or shut down. Stop safely if the hybrid warning worsens or propulsion becomes unreliable.