P0115 2013 Toyota RAV4 Code - Engine Coolant Temperature Circuit Malfunction

The P0115 code indicates a malfunction in the Engine Coolant Temperature (ECT) sensor circuit, which monitors the coolant's temperature to help regulate engine performance.

Symptoms may include poor fuel efficiency, rough idling, engine overheating, difficulty starting, or an illuminated Check Engine Light.

Common causes include a faulty ECT sensor, damaged or corroded wiring, a bad connection, or issues with the engine control module (ECM).

It’s possible to drive, but it’s not recommended as it may lead to engine overheating or other performance issues that could cause further damage.

Start by checking the ECT sensor and its wiring for damage or corrosion, then use a scan tool to monitor the sensor’s readings and verify if they're within the normal range.

Repairs typically involve replacing the ECT sensor, repairing damaged wiring, cleaning corroded connectors, or, in rare cases, replacing the ECM.

Replacing an ECT sensor typically costs between $100 and $300, including parts and labor, though costs may vary based on location and repair complexity.

While the thermostat itself doesn’t directly trigger the P0115 code, a stuck-open or stuck-closed thermostat can cause abnormal coolant temperatures, which may indirectly affect the sensor readings.

Clearing the code will turn off the Check Engine Light temporarily, but it won’t resolve the underlying issue, and the code will likely return if the problem isn’t fixed.

Regular maintenance, such as inspecting and cleaning electrical connections and replacing worn components like the ECT sensor and thermostat, can help prevent this code.