P0BC9: Hybrid/EV Battery Pack Cooling Fan 1 Sense Circuit Low
What to do
As P0BC7 — and check the pack's cooling intake for blockage first, because it is free and it produces exactly this.
What this code means
The fan's feedback signal is reading below its valid range — an open sense circuit, or a fan that genuinely is not turning at all. Those two need separating before anything is bought, and the control side and supply side (P0BBF) both have to be eliminated first. Argument at P0BC7.
Likely causes
Start here
- Blocked hybrid battery cooling fan intake · easy
- Faulty hybrid battery cooling fan · moderate
- Corroded or loose connector · easy
Less common
- Failed cooling fan motor · moderate
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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