Engine Coolant Temperature 2 / Ambient Air Temperature Correlation

Descripción

This code indicates a mismatch between the engine coolant temperature reading and the outside air temperature reading. The car's computer uses these readings to optimize fuel and air mixture for performance and efficiency.

Pasos de reparación

1. 1 Check coolant level and top off if low, as insufficient coolant can cause inaccurate temperature readings.
2. 2 Inspect the wiring and connectors for both the engine coolant temperature (ECT) sensor and the ambient air temperature (AAT) sensor for damage, corrosion, or loose connections.
3. 3 Use a scan tool to compare the ECT sensor 2 reading and ambient air temperature sensor reading when the engine is cold (sat overnight) — both should read close to actual ambient temperature.
4. 4 Test the ambient air temperature sensor with a multimeter to verify it is reading within specification and replace if faulty.
5. 5 Test the engine coolant temperature sensor 2 with a multimeter to verify proper resistance values at known temperatures and replace if out of range.
6. 6 Inspect the thermostat for proper operation — a thermostat stuck open can cause the engine to run cooler than expected, triggering a correlation error. Replace if faulty.
7. 7 Clear the diagnostic trouble code after repairs and drive the vehicle through a complete warm-up cycle to verify the code does not return.

Diagnóstico y costo