P011B code meaning
Engine Coolant Temperature/Intake Air Temperature Correlation
Powertrain system Generic code P01xx codes Check engine light
What P011B means
After a long standstill the coolant and the intake air should both have settled close to ambient temperature. P011B compares the two sensors at start-up and is set when they disagree without either sensor showing a circuit fault. In the documented GM/Saab version the engine must have been off for more than 10 hours with no preheater detected; the fault counts if coolant reads at least 20 °C above intake air, or intake air at least 30 °C above coolant, and the coolant reading barely moves (2 °C or less) in the first 45 s. The code does not say which sensor is wrong – that has to be found by comparing both with the actual ambient temperature. Toyota resolved false settings on some 2015 V6 engines with new software. Ford and GM report the same idea under the individual sensor codes.
P011B at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyMedium, DIY possible
- Typical labor0.5 to 2 hours
- Clears after repairAfter a drive cycle
Symptoms of P011B
- Check engine light on
- Usually no change in driving
- With a wrong coolant reading: poor cold start, higher consumption or odd fan behaviour
- Code often returns only after an overnight soak
Common causes of P011B
- Most likelyCoolant temperature sensor stuck or drifting
- PossibleIntake air temperature sensor drifting or heat-soaked
- PossibleUndetected preheater or uneven cooling
- PossibleContact resistance at a sensor connector or ground
- Less likelyControl module software (false setting, update available)
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Engine coolant temperature sensorIntake air temperature sensorSensor wiring
What each part of P011B means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 1 | Area: fuel and air metering. |
| 1B | The exact fault in that area. |
What to do next
- Note P011B and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P011B
What does P011B mean?
P011B means "Engine Coolant Temperature/Intake Air Temperature Correlation". After a long standstill the coolant and the intake air should both have settled close to ambient temperature. It is a generic code, so it means the same on every make.
Is it safe to drive with P011B?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P011B fail an emissions test?
Yes, it can. P011B is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P011B to fix?
Difficulty: medium. A typical repair takes 0.5 to 2 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P011B clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.