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.
DTC P0116: Engine Coolant Temperature (ECT) Sensor Circuit Range/ Performance Problem: General Description
The engine control module (ECM)/powertrain control module (PCM) supplies voltage to the engine coolant temperature (ECT) signal circuit (about 5 V) through a pull-up resistor. As the engine coolant cools, ECT sensor resistance increases, and the ECM/PCM detects a high signal voltage. As the engine coolant warms, ECT sensor resistance decreases, and the ECM/PCM detects a low signal voltage.
If the ECT output voltage after driving a set time after starting the engine does not reach a set temperature, or when the difference between the ECT output voltage when driving and the output voltage of the ECT after the engine is stopped a set time does not change a certain amount, a malfunction is detected and a DTC is stored.
NO RELATED
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra cost to you.
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.