Damaged or chafed motor phase cable (U, V, or W) causing a short to ground or between phases; Loose or corroded connector pins at the motor or inverter terminals; Internal short or open winding in the drive motor stator; Failed inverter module or power transistor inside the motor control unit; Insulation breakdown due to moisture, heat, or contamination in the motor housing; Faulty current sensor or voltage sensing circuit within the inverter; Aftermarket or improper wiring repairs that alter resistance or shielding

DTC codes / P0Cxx · Hybrid propulsion / P0C07

P0C07Drive Motor A Phase U-V-W Circuit High

Q: What does code P0C07 mean?

Drive Motor A Phase U-V-W Circuit High. P0C07 indicates that the hybrid or electric vehicle's motor control module has detected an abnormally high current or voltage condition in the phase U, V, or W circuit of drive motor A. The computer monitors the three-phase inverter output and sets this code when the circuit exceeds safe limits, often due to a short, open, or insulation fault.

P0C07 indicates that the hybrid or electric vehicle's motor control module has detected an abnormally high current or voltage condition in the phase U, V, or W circuit of drive motor A. The computer monitors the three-phase inverter output and sets this code when the circuit exceeds safe limits, often due to a short, open, or insulation fault.

SystemPowertrain

Code typeGeneric (all makes)

SeverityHigh

Fix difficultyProfessional

AreaHybrid propulsion

Symptoms you may notice

Illumination of the check engine light or hybrid system warning lamp
Often no symptoms besides the warning light, especially if the fault is intermittent
Reduced power or limp-home mode with limited motor output
Vehicle may refuse to start or shift into gear if the high-voltage system is disabled
Possible shuddering or rough operation under acceleration if one phase is weak
In some cases, the engine may run continuously or the vehicle may default to gasoline-only operation

Common causes, most likely first

Damaged or chafed motor phase cable (U, V, or W) causing a short to ground or between phases
Loose or corroded connector pins at the motor or inverter terminals
Internal short or open winding in the drive motor stator
Failed inverter module or power transistor inside the motor control unit
Insulation breakdown due to moisture, heat, or contamination in the motor housing
Faulty current sensor or voltage sensing circuit within the inverter
Aftermarket or improper wiring repairs that alter resistance or shielding

How to diagnose and fix it

Perform a visual inspection of the motor phase cables and connectors for chafing, corrosion, or loose pins
Use a digital multimeter to check resistance between each phase and ground, and between phases, with the high-voltage system disabled
Measure insulation resistance with a megohmmeter to detect subtle winding or cable leakage
Inspect the inverter terminals and motor connector for signs of arcing, overheating, or moisture intrusion
Check for technical service bulletins or software updates for the motor control module that may address false setting
If the fault persists, perform a guided diagnostic using the manufacturer's scan tool to monitor phase current and voltage live data
Replace the faulty motor phase cable, connector, or motor assembly as indicated by test results

What the phase circuit code really means

A high voltage or current reading on a phase circuit does not always mean the motor is bad; a poor connection at the inverter can mimic a failed winding.
Intermittent codes often appear after driving through deep water or after a car wash, pointing to moisture ingress in the motor connector rather than a hard failure.
Some vehicles set P0C07 when the 12-volt battery is weak because the inverter's self-test runs at startup and misreads a low reference voltage.
A shorted phase cable can be caused by a rodent chewing through the insulation, which is easily missed if only the motor and inverter are inspected.
The code can be stored by a faulty current sensor inside the inverter even when the actual phase circuit is healthy, so live data comparison is essential before replacing parts.

Can I keep driving with P0C07?

Do not continue driving with this code active, because a high-voltage phase fault can cause sudden loss of power or damage the inverter and motor. Have the vehicle towed to a qualified hybrid or electric vehicle technician for diagnosis.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.