Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Engine Coolant Temperature (ECT) Sensor
The Engine Coolant Temperature (ECT) sensor (thermistor) is installed at rear of intake manifold, near left rocker arm cover. See Figure. The coolant temperature sensor resistance is high at low temperatures and decreases as temperature rises. The ECA applies a 9-volt reference voltage to sensor and monitors the resultant voltage drop across sensor.
If coolant temperature is less than 70°F or greater than 230°F, the ECA will cut off all EGR flow. Also, if engine coolant overheats from prolonged idle, the ECA will advance initial engine timing to increase engine speed and improve cooling.
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
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