P0B17: Hybrid/EV Battery Pack Voltage Sense B Circuit High
What to do
Take this one seriously and do not defer it. A section reading high is usually a wiring fault, but the alternative — a part of the battery genuinely being overcharged — is the failure a lithium pack handles worst. If the car limits or refuses charging, that is it protecting itself. Have it looked at before charging again if you reasonably can.
What this code means
Sense circuit B is reading above its valid range.
High is the harder direction to explain innocently. A sense line cannot invent voltage on its own, so the readings that push it over the top are a short to a different tap further up the string, a short to another circuit, or a section genuinely being overcharged — and the last of those is the one that matters.
Overcharging is the failure mode a lithium pack does not forgive. Where a low reading is usually a wiring fault with a cheap ending, a high one has a branch that ends in thermal runaway, so it is treated more urgently by the car and should be by the reader. Expect charging to be limited or refused until it is resolved, and treat that as protection rather than as a second fault.
The measurement argument is at P0B14.
Likely causes
Start here
- Damaged cell voltage sense harness · specialist
Less common
- Wiring shorted to voltage · moderate
- Faulty battery pack sensor module · specialist
- Weak or failed cell group in the battery pack · 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.
Sign in or create an account to add what you found about P0B17.