P011E: Engine Coolant Temperature 1 / Ambient Air Temperature Correlation

What does P011E mean?

After a long standstill, typically six to eight hours, the coolant should have cooled to roughly the outside air temperature measured by the ambient sensor in the bumper or mirror. P011E compares coolant temperature sensor 1 with the ambient sensor at start-up and is set when they differ beyond a calibrated limit and no preheater was detected. The code does not say which of the two sensors is wrong. No manufacturer document using exactly this code was found; the description rests on the CARB requirement for coolant sensor plausibility and on the same cold-soak comparison that Ford (reported as P0071), GM/Saab and Mazda perform under other codes.

The code tells you which monitor failed, not which part is broken. Test before replacing parts.

Symptoms

• Check engine light on
• Usually no driving symptoms
• Outside temperature display possibly wrong

Common causes

• Medium Coolant temperature sensor 1 drifting
• Medium Ambient temperature sensor drifting or affected by engine heat or sun
• Medium Preheater not detected
• Low Contact resistance in one sensor's connector or wiring

Likelihood is a general estimate across vehicles; your make and model may differ.