P0C75 is logged when the high-voltage bus loses its voltage faster than expected after the contactors open. At shutdown the inverter's DC-link capacitor is drained through a discharge resistor or an active discharge circuit, and from capacitance and resistance the controller knows roughly how long that should take. A much quicker drop points to lost capacitance, a lower resistance than designed, a leakage path or a wrong voltage reading. A capacitor diagnostic patent (EP2682769B1) uses the same comparison to detect capacitor ageing. No manufacturer documents P0C75 publicly; GM publishes only the opposite check, P0C76. The driver usually sees a hybrid warning lamp, and depending on the make the next start may be blocked.
High severity. Can I keep driving?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.
Symptoms
- Hybrid or EV system warning lamp
- Vehicle may not become ready to drive
Most likely causes
- DC-link capacitor lost capacitance through ageing or damage
- Additional load or leakage path on the high-voltage bus
- Bus voltage measured incorrectly by the inverter or battery module
- Discharge resistor or circuit with too low a resistance
What to check, in order
Start with the simplest. You can tick off each step.
Good to know
- It can trigger limp mode.
- It affects emissions.
What each character of P0C75 means
- P: Powertrain: engine and transmission
- 0: Generic code: same on every make
- C: Subsystem depends on the code range
- 75: Specific fault in that system
Frequently asked questions
Can I keep driving with code P0C75?
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 P0C75?
The most common causes are: dC-link capacitor lost capacitance through ageing or damage; additional load or leakage path on the high-voltage bus; bus voltage measured incorrectly by the inverter or battery module.
Related codes
- P0C76Hybrid/EV Battery System Discharge Time Too Long
- P0C77Hybrid/EV Battery System Precharge Time Too Short
- P0C78Hybrid/EV Battery System Precharge Time Too Long
Sources
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.