Powertrain, generic · Fuel and air metering

P011B Engine Coolant Temperature/Intake Air Temperature Correlation

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

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.

Likely causes

Coolant temperature sensor stuck or drifting
Intake air temperature sensor drifting or heat-soaked
Undetected preheater or uneven cooling
Contact resistance at a sensor connector or ground
Control module software (false setting, update available)

Symptoms

  • 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

Repair estimate

DifficultyMediumDIY possible
Parts and labour€40–300
Time0.5–2 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

engine coolant temperature sensorintake air temperature sensorsensor wiring

Related codes

P0111P0116P0117P0118P0128P00CE

References: law.cornell.edu, saabwisonline.com, static.nhtsa.gov, newtonnet.co.uk.