P0ABA: Hybrid/EV Battery Pack Voltage Sense A Circuit
What to do
A scan tool showing impossible pack voltage with this code stored is describing a broken measurement, not a dead battery — worth knowing before anyone quotes on the pack. Sense wiring and connectors first.
What this code means
The circuit through which the module reads the pack's voltage has failed — the sense wires, not the power path.
Sensing and carrying are separate jobs. The heavy cables deliver current; thin sense wires, tapped at the terminals, deliver the measurement, so that contact resistance in the power path cannot corrupt the reading. A fault in the sense circuit therefore produces battery voltage readings that are wrong or missing while the battery itself is untouched — and a module that cannot verify pack voltage acts conservatively, up to refusing to close the contactors.
The pattern to recognise: alarming battery readings — zero volts, impossible values — on a car that was driving normally moments before. A battery does not do that; a broken sense wire does.
Likely causes
Start here
- Open circuit in sensor wiring · moderate
- Corroded or loose connector · easy
Less common
- Faulty battery pack sensor module · 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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