P0C0C: Drive Motor A Inverter Power Supply Circuit Low

P0C0C reports that the supply voltage of the motor A inverter is present but too low, while P0C0B covers a lost or open supply and P0C0D a supply that is too high. Which supply is meant depends on the maker: GM ties its sibling P0C0B to the gate-drive supply of the IGBTs, Mercedes to the high-voltage feed. Audi documents P0C0C on the 2025 and 2026 A6 and Q6 e-tron family: stored in the electric drive modules together with P0E8D, it comes with a red high-voltage fault warning to stop safely, and the bulletin calls for replacing the affected front or rear power electronics. CARB requires circuit monitoring of hybrid components. Without a stable supply the inverter cannot switch, so drive power is cut.

Symptoms

• Red high-voltage system warning asking to stop safely
• Loss of drive power or vehicle will not get ready to drive

Most likely causes

• Internal fault of the drive power electronics (Audi TSB 2081725)
• Weak 12 V supply, poor ground or high-resistance connector at the inverter
• Weak 12 V battery or DC/DC converter output

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. With the connector unplugged, check whether the signal wire is making contact with ground.
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 P0C0C means

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

Frequently asked questions

Can I keep driving with code P0C0C?

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 P0C0C?

The most common causes are: internal fault of the drive power electronics (Audi TSB 2081725); weak 12 V supply, poor ground or high-resistance connector at the inverter; weak 12 V battery or DC/DC converter output.

Related codes

• P0C0BDrive Motor A Inverter Power Supply Circuit/Open
• P0C0DDrive Motor A Inverter Power Supply Circuit High
• P0C0FDrive Motor B Inverter Power Supply Circuit Low
• P0A78Drive Motor A Inverter Performance
• P0E8DDrive Motor A Inverter Voltage Sensor B Circuit Range/Performance

Sources

• static.nhtsa.gov: MC 11032197 0001
• law.cornell.edu: 13 CCR 1968.2
• gsi.ext.gm.com: 19OBDG01 Hybrid Diagnostics

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.