P2231

O2 Sensor Signal Circuit Shorted to Heater Circuit Bank 1 Sensor 1

Q: Is it safe to drive with P2231?

Yes for short trips — it won't strand you — but fuel control and emissions suffer while it's active, so repair it before long-term driving.

Q: Can I just clear P2231?

You can, but a signal-to-heater short from wiring or a bad sensor will bring it back until repaired.

Fuel & air metering (O2 sensor) Generic OBD-II Medium

What it means

P2231 means the signal wire of the bank 1, sensor 1 (upstream) oxygen sensor has shorted to its own heater circuit, so the ECM is getting a corrupted reading. Because this sensor guides fuel trim, a bad signal upsets the air-fuel mixture and can cause rough running and poor economy. It's most often chafed or heat-damaged wiring, a connector fault, or an internally shorted sensor.

Medium

Can I keep driving? Drivable, but a faulty upstream O2 sensor throws off fuel control, hurting economy and emissions and possibly causing rough running; repair soon.

Real-world scan data

Seen in

105

scans in the past year

Found in

<0.1%

of scans

<0.1%

of scans that found faults

Figures reflect only diagnostic scans recorded through our own apps and tools. Cars are typically scanned because a symptom or warning light prompted it, so these counts describe our scan records — not the incidence of faults in any model, and not the quality, reliability, or safety of any vehicle. No comparison between manufacturers or models is implied. All trademarks belong to their respective owners; no affiliation or endorsement is implied.

Common symptoms

What you'll notice

Check-engine light on
Rough or uneven idle
Increased fuel consumption
Engine surge or hesitation

Common causes

Most likely first

Faulty upstream oxygen sensor (bank 1, sensor 1)Likely
Signal wire shorted to the heater circuit inside the harness or sensorCommon
Chafed or melted wiring near hot exhaust bridging the two circuitsCommon
Poor connection or corrosion at the O2 sensor connectorLess often

How to diagnose & fix

Work through it in order

Read freeze-frame data and note the O2 sensor's live signal behaviour.
Inspect the O2 sensor wiring and connector for chafing, melting, or corrosion, especially where it routes near the exhaust.
Check for a short between the signal and heater circuits with the connector unplugged.
Repair or reroute damaged harness sections away from heat.
Replace the upstream O2 sensor if wiring is good but the short is internal, then clear and re-test.

FAQ

Quick answers

Is it safe to drive with P2231?+

Yes for short trips — it won't strand you — but fuel control and emissions suffer while it's active, so repair it before long-term driving.

Can I just clear P2231?+

You can, but a signal-to-heater short from wiring or a bad sensor will bring it back until repaired.

Read & clear P2231 yourself

Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.

▶ Get it on Google Play

✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX