Faulty inverter assembly or internal voltage sensor for drive motor B; Damaged or corroded high-voltage power supply wiring or connectors; Poor ground connection for the inverter or motor control module; High-voltage battery pack supplying excessive voltage due to a fault in the battery management system; Software error in the inverter control module requiring recalibration or update; Failed voltage regulator or DC-DC converter affecting the low-voltage supply to the inverter electronics

DTC codes / P0Cxx · Hybrid propulsion / P0C10

P0C10Drive Motor B Inverter Power Supply Circuit High

Q: What does code P0C10 mean?

Drive Motor B Inverter Power Supply Circuit High. P0C10 indicates that the inverter responsible for supplying high-voltage power to drive motor B has reported an abnormally high voltage on its power supply circuit. The vehicle's control module sets this code when the monitored supply voltage exceeds the expected threshold, often due to a fault in the inverter's internal sensing or the high-voltage supply path.

P0C10 indicates that the inverter responsible for supplying high-voltage power to drive motor B has reported an abnormally high voltage on its power supply circuit. The vehicle's control module sets this code when the monitored supply voltage exceeds the expected threshold, often due to a fault in the inverter's internal sensing or the high-voltage supply path.

SystemPowertrain

Code typeGeneric (all makes)

SeverityHigh

Fix difficultyProfessional

AreaHybrid propulsion

Symptoms you may notice

Illumination of the check engine light or service vehicle soon message
Reduced power or limp mode, as the hybrid or electric system limits motor output
The vehicle may refuse to start or enter ready-to-drive mode
Intermittent loss of drive motor assist or hesitation during acceleration
Often no symptoms besides the warning light, especially if the fault is intermittent

Common causes, most likely first

Faulty inverter assembly or internal voltage sensor for drive motor B
Damaged or corroded high-voltage power supply wiring or connectors
Poor ground connection for the inverter or motor control module
High-voltage battery pack supplying excessive voltage due to a fault in the battery management system
Software error in the inverter control module requiring recalibration or update
Failed voltage regulator or DC-DC converter affecting the low-voltage supply to the inverter electronics

How to diagnose and fix it

Perform a visual inspection of the high-voltage wiring and connectors for damage, corrosion, or loose connections
Check and clean all ground connections related to the inverter and motor control module
Use a diagnostic scan tool to read live data for the inverter power supply voltage and compare with actual measured voltage
Test the high-voltage battery pack voltage and ensure it is within specification
Inspect the inverter assembly for signs of overheating, coolant leaks, or physical damage
Reprogram or update the inverter control module software if applicable
Replace the inverter assembly if internal voltage sensing is confirmed faulty

High-voltage supply faults often misdiagnosed

A high voltage reading on the inverter supply circuit can be caused by a poor ground connection, which raises the reference voltage and triggers the code even when the high-voltage battery is healthy.
Technicians sometimes replace the inverter only to find the root cause is a failing high-voltage battery pack that intermittently outputs excessive voltage under load.
The code can set intermittently due to a loose connector that only loses contact during vibration, so a wiggle test of the high-voltage connectors is essential.
On some vehicles, a low 12-volt battery or a failing DC-DC converter can cause the inverter's internal electronics to misreport voltage, leading to a false P0C10.
Always follow the manufacturer's high-voltage safety procedures; the inverter supply circuit carries lethal voltage even when the vehicle is off.

Can I keep driving with P0C10?

Do not continue driving with this code active, as a high-voltage supply fault can lead to sudden loss of power or damage to the inverter and motor. Have the vehicle inspected by a qualified high-voltage technician before further use.

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.