OBD-II code · Powertrain (generic)
P011B Engine Coolant Temperature/Intake Air Temperature Correlation
ECT and IAT readings disagree at long soak (engine off for hours) when both should match ambient. The intake air temperature sensor feeds the ECM's density calculation — a drifted reading miscalculates fuel mass and pushes mixture lean (cold reading) or rich (hot reading).
Is it safe to drive with P011B?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyOne sensor drifted
Symptoms
- Check engine light on
- Cooling fan runs constantly or not at all
- Cabin heater weak or excessively hot
- Possible long warm-up time or hard cold start
Repair at a glance
- Difficulty
- Easy
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.3–1.5 h
- Emissions test
- Likely to fail
- After the fix
- A drive cycle is needed before the light stays off
- Parts involved
- Ect Sensor, Iat Sensor
Related codes
- P0118Engine Coolant Temperature Sensor High Input
- P0119Engine Coolant Temperature Sensor Circuit Intermittent
- P011AEngine Coolant Temperature Sensor 1/2 Correlation
- P011CCharge Air Cooler Temperature/Intake Air Temperature Correlation Bank 1
- P011DCharge Air Cooler Temperature/Intake Air Temperature Correlation Bank 2
- P011EEngine Coolant Temperature 1 / Ambient Air Temperature Correlation
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.