P0C7A: Drive Motor B Inverter Voltage Too High

P0C7A is the overvoltage code for the inverter of drive motor B, which on many all-wheel-drive hybrids is the rear motor. Mitsubishi documents it for the Outlander PHEV: in the 2018 model the rear motor control unit has a hardware high-voltage switch that closes at 420 V, a higher limit than the 370 V of the front unit, and the code sets after a single trip with the power stage active or after 0.5 s with it switched off. The manual blames the high-voltage circuit or the rear control unit and starts with the rear battery cable connections; the 2023 model keeps the code under a rear-motor overvoltage name. Regeneration spikes, contactor events and sensing errors are the usual suspects. Expect a warning lamp and reduced drive power.

Symptoms

• Hybrid or EV warning lamp
• Reduced drive power, rear axle drive may be unavailable

Most likely causes

• Rear battery cable connection loose at the rear motor control unit
• Rear motor control unit or its voltage detection faulty
• Voltage spike from regeneration or a contactor event

What to check, in order

Start with the simplest. You can tick off each step.

1. Read the codes with a hybrid-compatible scanner and write down the freeze frame data
2. Check the sensor's ground and make sure the signal wire is not receiving voltage from another circuit.
3. Make sure the battery cooling air intake is clean
4. Check the 12 V auxiliary battery, which can also trigger warnings
5. Leave any high-voltage measurements to a specialized repair shop

Good to know

• It can trigger limp mode.
• It affects emissions.

What each character of P0C7A means

• P: Powertrain: engine and transmission
• 0: Generic code: same on every make
• C: Subsystem depends on the code range
• 7A: Specific fault in that system

Frequently asked questions

Can I keep driving with code P0C7A?

If the car still runs, drive as little as possible and go to a specialized repair shop. Do not touch the orange cables: they carry high voltage.

What causes code P0C7A?

The most common causes are: rear battery cable connection loose at the rear motor control unit; rear motor control unit or its voltage detection faulty; voltage spike from regeneration or a contactor event.

Related codes

• P0C79Drive Motor A Inverter Voltage Too High
• P0C7BGenerator Inverter Voltage Too High
• P0A79Drive Motor B Inverter Performance
• P0DA4Drive Motor B Inverter Voltage Sensor A Circuit Range/Performance

Sources

• mitsubishitechinfo.com: M154933570004000USA
• mitsubishitechinfo.com: N503230090000900USA
• law.cornell.edu: 13 CCR 1968.2

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.