What it means
The drive motor A phase U-V-W output reports a circuit low 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
The inverter drives Drive Motor A through its U, V, and W phase outputs, with switching devices controlling current in each phase. P0C06 sets when the module detects a phase output voltage or signal that is too low, which may result from a phase wire shorted to ground, a failed low-side switch, or high resistance at a corroded connection.
Common causes
Most likely first.
- Phase wire shorted to ground
- Low-side switch open in inverter
- 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
- Review freeze-frame and live data for Drive Motor A phase output, current, torque request, and related inverter faults to see when the low condition occurs.
- With the high-voltage system disabled according to the manufacturer's procedure, inspect the U, V, and W wiring and connectors for ground contact, corrosion, or damaged insulation.
- Check the phase connector terminals for corrosion or poor contact that could create resistance, including pins that are loose or heat-damaged.
- Have a qualified technician test the phase wiring for an unintended short to ground using the manufacturer's isolation procedure.
- If the harness is sound, test the Drive Motor A inverter low-side switching output against the manufacturer's specification.
Common fixes
- Clean or repair corroded Drive Motor A phase terminals.
- Repair phase wire insulation or wiring that is shorted to ground.
- Replace a damaged connector or terminal causing high contact resistance.
- Repair or replace the inverter if a failed low-side switch is confirmed.
Can I keep driving?
Limit driving and avoid high power demand because Drive Motor A may lose torque or the vehicle may enter limp mode or shut down. Stop safely if power becomes unstable or a hybrid-system warning indicates a fault escalation.
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.