P0DE7: Hybrid/EV Battery Pack Cell Voltage High
What to do
Do not charge the car again until it has been inspected, including at home. The car has stopped for a reason that can permanently damage the battery and in the worst case start a fire. It will usually still drive, but arrange for it to be looked at rather than continuing to charge it.
What this code means
One or more cell groups in the traction battery has risen above its maximum safe voltage.
The ceiling is the more dangerous of a lithium cell's two limits, and P0D85 sets out why: above it the electrolyte breaks down and lithium plates out onto the anode as metal, permanently and cumulatively, eventually as structures that can bridge the cell internally.
What makes this code different from P0D85 is where the measurement comes from. That one is the charging system reporting its own output. This is the battery management system reporting a cell group — the last line of defence, and the one that acts when the charging side has already failed to protect the pack.
Two causes, and they need separating before anything is charged again. The charging system may genuinely have overshot, in which case the codes at P0D85 and P0D4C should be there too. Or the measurement is wrong — a sense wire with high resistance reads a group as higher than it is, which is the P0B14 argument, and the pack is fine while the car is right to refuse.
Either way the car stopping is correct, and clearing the code to try again is the one response that could turn an electrical fault into a fire.
Likely causes
Start here
- Damaged cell voltage sense harness · specialist
- Faulty battery pack sensor module · specialist
Less common
- Faulty on-board charger · specialist
- Weak or failed cell group in the battery pack · specialist
- Corroded or loose connector · 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
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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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