Engine Coolant Temperature 1 / Ambient Air Temperature Correlation

Descripción

This code indicates a discrepancy between the engine coolant temperature and the ambient (outside) air temperature. The computer expects these two temperatures to be within a certain range of each other, and this code means they are not.

Pasos de reparación

1. 1 Check for other related diagnostic trouble codes (DTCs) that may help pinpoint whether the coolant temperature sensor or ambient air temperature sensor is at fault.
2. 2 Inspect the engine coolant temperature (ECT) sensor connector and wiring for corrosion, damage, or loose connections, and repair as needed.
3. 3 Inspect the ambient air temperature (AAT) sensor connector and wiring for corrosion, damage, or loose connections, and repair as needed.
4. 4 Compare the ECT sensor and AAT sensor readings using an OBD-II scan tool with live data after the vehicle has sat overnight — both should read within a few degrees of each other when the engine is cold.
5. 5 Replace the engine coolant temperature sensor if its reading is significantly off from the ambient air temperature on a cold engine.
6. 6 Replace the ambient air temperature sensor if its reading is inaccurate compared to the actual outside temperature.
7. 7 Inspect and replace the thermostat if the engine is not reaching proper operating temperature or is overheating, which could cause a correlation mismatch.
8. 8 Have the engine control module (ECM) inspected and tested by a professional if all sensors, wiring, and the thermostat have been verified as functioning correctly.

Diagnóstico y costo