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: ECT Sensor 1 Range/ Performance Problem
- Turn the ignition switch ON (II).
- Check ECT SENSOR 1 in the DATA LIST with the HDS.
Is about 176°F (80°C) or more, or 0.78 V or less indicated?
YES - Go to step 6.
NO - Go to step 3.
- Note the value of ECT SENSOR 1 in the DATA LIST with the HDS.
- Start the engine. Hold the engine speed at 3,000 rpm without load (in Park or neutral) until the radiator fan comes on, then let it idle.
- Check ECT SENSOR 1 in the DATA LIST with the HDS.
Does ECT SENSOR 1 change 18°F (10°C) or more?
YES - Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at ECT sensor 1 and the ECM/PCM.
NO - Go to step 11.
- Note the value of ECT SENSOR 1 in the DATA LIST with the HDS.
- Turn the ignition switch OFF.
- Open the hood, and let the engine cool for 3 hours.
- Turn the ignition switch ON (II).
- Check ECT SENSOR 1 in the DATA LIST with the HDS.
Does ECT SENSOR 1 change 18°F (10°C)or more?
YES - Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at ECT sensor 1 and the ECM/PCM.
NO - Go to step 11.
- Turn the ignition switch OFF.
- Replace ECT sensor 1 (see ECT SENSOR 1 REPLACEMENT ).
- Turn the ignition switch ON (II).
- Reset the ECM/PCM with the HDS.
- Do the ECM/PCM idle learn procedure (see ECM/PCM IDLE LEARN PROCEDURE ).
- Check for Temporary DTCs or DTCs with the HDS.
Is DTC P0116 indicated?
YES - Check for poor connections or loose terminals at ECT sensor 1 and the ECM/PCM, then go to step 1.
NO - Troubleshooting is complete. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTCs troubleshooting.
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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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