DTC P011B: Engine Coolant Temperature / Intake Air Temperature Correlation [08/2015 - 08/2017]: Description

WARNING: This page is about a different car, the 2018 Toyota Sequoia, 2017 Toyota Sequoia, and 2016 Toyota Sequoia. However, it is still accessible from the selected car via links, so may be relevant.

The engine has two temperature sensors, an Engine Coolant Temperature (ECT) sensor and an Intake Air Temperature (IAT) sensor, to detect the temperature while the engine is in operation. A thermistor, whose resistance value varies according to the temperature, is built into each sensor. When the temperature is low, the resistance of the thermistor increases. When the temperature is high, the resistance drops. These variations in resistance are transmitted to the ECM as voltage changes. Based on these temperature signals output from the sensors, the ECM determines the fuel injection time and the ignition timing to control the engine.

DTC Code	DTC Detection Condition	Trouble Area
P011B	All of the following conditions are met (2 trip detection logic): The battery voltage is 10.5 V or higher. 7 hours or more have elapsed from engine stop on the previous trip. 102 seconds after a cold engine start. The minimum Intake Air Temperature (IAT) after the engine starts is higher than -10°C (14°F). The average Engine Coolant Temperature (ECT) before the engine starts is higher than -10°C (14°F). The difference between the readings of ECT and IAT is higher than 25°C (45°F).	IAT sensor ECT sensor ECM

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HINT:

Waiting is required to prevent the temperature of the engine from affecting the readings. If the engine has been operated recently, it will not be possible to accurately compare the readings.

For diagnosis, in order to duplicate the detection conditions of the DTC, it is necessary to park the vehicle for 7 hours. Parking the vehicle for 7 hours ensures that the actual temperature of the ECT and IAT are very similar. When the vehicle has been parked for less than 7 hours, differences in the readings may exist. However, this does not necessarily indicate a fault.