P011B 2015 Toyota RAV4 Code - Engine Coolant Temperature/Intake Air Temperature Correlation

P011B indicates an issue with the correlation between the engine coolant temperature (ECT) sensor and the intake air temperature (IAT) sensor readings. The ECM detects a mismatch between these two temperature signals.

Symptoms may include an illuminated check engine light, poor fuel economy, rough engine performance, difficulty starting, or the engine running hotter or cooler than normal.

Common causes include faulty ECT or IAT sensors, wiring or connector issues, a malfunctioning ECM, a stuck thermostat, or low coolant levels.

While the vehicle may still be drivable, it’s not recommended to ignore this code as it can lead to engine performance issues or potential overheating if left unresolved.

Start by inspecting the ECT and IAT sensors and their wiring for damage or corrosion. Use a scan tool to compare the temperature readings of both sensors and check for discrepancies.

Repairs may include replacing a faulty ECT or IAT sensor, repairing damaged wiring or connectors, refilling or flushing the coolant, or replacing a stuck thermostat.

Repair costs vary based on the cause. Replacing a sensor may cost $100–$300, while thermostat replacement or wiring repairs could range from $150–$500.

Yes, low coolant levels can cause inaccurate readings from the ECT sensor, leading to a P011B code. Always check and maintain proper coolant levels.

A dirty air filter typically won’t cause this code directly, but it can affect engine performance. It’s worth inspecting and replacing the air filter if needed during diagnosis.

Clearing the code without addressing the root cause will only temporarily turn off the check engine light. The code is likely to return until the underlying issue is fixed.