P0C75: Hybrid/EV Battery System Discharge Time Too Short
What to do
Usually this reflects an ageing capacitor bank rather than a hazard, particularly if a precharge timing code is stored alongside it — the two together describe one tired component. The alternative is an unintended path to earth, so it is worth diagnosing rather than clearing, even though the car may feel entirely normal.
What this code means
After shutdown, the high-voltage system discharged faster than expected.
The discharge sequence and why it is timed are at P0C76. Too fast sounds harmless and mostly is, but it is measuring the same circuit from the other side and the readings are worth knowing.
The benign one is lost capacitance — a capacitor bank that has aged will both charge and discharge more quickly than a healthy one, and this code often arrives beside P0C77 for exactly that reason. Two codes describing one tired component.
The less benign one is an unintended path to earth, which drains the capacitors faster than the designed bleed alone would. That overlaps with insulation faults, and it is the reading that justifies not ignoring this code even though nothing about the car feels wrong.
Likely causes
Start here
- Faulty power inverter · specialist
Less common
- Damaged high voltage cable insulation · specialist
- Water ingress into a high voltage connector · specialist
- Failed high voltage discharge circuit · specialist
Symptoms
Components involved
Information, not instruction
CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.
Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Community experience
Be the first to write this up
Nothing posted about this yet. Whatever you found is worth writing down — even a dead end saves someone the same afternoon.
What makes one worth reading:
- The car — make, model, year and engine. The same fault behaves differently on each.
- What you measured, not only what you replaced.
- What actually fixed it — or that nothing did, which is worth knowing too.
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