P011B

Engine Coolant Temperature/Intake Air Temperature Correlation

Q: Is it safe to drive with P011B?

Yes. This code just means two temperature sensors disagree; the engine runs, though a wrong cold reading can make cold starts and warm-up slightly rough.

Q: Can I just clear P011B?

It comes back once the ECM compares the two sensors again. The drifting sensor has to be identified and replaced.

Fuel & air metering Generic OBD-II Low

What it means

P011B means the engine coolant temperature and intake air temperature sensors disagree by more than expected — after the car has sat cold, both should read close to ambient. It usually points to one sensor drifting out of range, which can throw off cold-start fueling but rarely leaves the car undriveable.

Low

Can I keep driving? Yes — it's usually one temperature sensor drifting; the car runs, though cold starts and warm-up may be slightly rough until it's fixed.

Real-world scan data

Seen in

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 hard starting when cold, from a wrong temperature reading
Slightly reduced fuel economy

Common causes

Most likely first

Faulty or drifting intake air temperature (IAT) sensorLikely
Faulty or drifting engine coolant temperature (ECT) sensorCommon
Poor connection or damaged wiring at either sensorCommon
A genuine cooling fault (e.g. stuck thermostat) skewing one reading before a cold startLess often

How to diagnose & fix

Work through it in order

After the engine has sat overnight, compare IAT and ECT readings on a scan tool — cold, they should be close.
The sensor whose reading is furthest from ambient is usually the faulty one.
Inspect that sensor's wiring and connector, then replace the drifting sensor.
Confirm the engine actually reaches normal operating temperature (thermostat OK).
Clear and retest.

FAQ

Quick answers

Is it safe to drive with P011B?+

Yes. This code just means two temperature sensors disagree; the engine runs, though a wrong cold reading can make cold starts and warm-up slightly rough.

Can I just clear P011B?+

It comes back once the ECM compares the two sensors again. The drifting sensor has to be identified and replaced.

Read & clear P011B 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