P2249: O2 Sensor Reference Voltage Circuit Low Bank 2 Sensor 1
What to do
Expect worse economy and reduced power. Ask what other sensors are reporting — a shorted reference line takes several with it and is one repair, not several.
What this code means
The bank 2 reference voltage circuit reads below its valid range, normally a short to ground. As at P2245, a shorted reference pulls down everything sharing that supply, so what else is faulted is the first question.
Likely causes
Start here
- Wiring shorted to ground · moderate
- Failed sensor reference voltage supply · moderate
- Faulty oxygen sensor · moderate
Less common
- Melted wiring against the exhaust · moderate
Symptoms
Components involved
Information, not instruction
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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.
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