P0116 - Engine Coolant Temperature Circuit Range/Performance

The coolant temperature sensor signal is outside the expected operating range.

Code Overview

The coolant temperature sensor signal is outside the expected operating range.

Common Causes

• Coolant temperature sensor reading skewed
• Thermostat stuck open or not regulating correctly
• Low coolant level or trapped air in the system
• Wiring or connector issue at the ECT sensor

Symptoms

• Temperature reading does not match actual warm-up behavior
• Poor fuel economy during warm-up
• Cooling fan or temperature-gauge behavior may seem off

Diagnostic Steps

1. Compare ECT to ambient temperature on a cold start
2. Inspect coolant level and make sure the system is full with no trapped air
3. Review warm-up behavior to see whether the thermostat is regulating correctly
4. Inspect the ECT connector and wiring before replacing parts

Repair Difficulty

Moderate

General difficulty estimate for the most common repair path.

Likely Repairs & Cost Guides

Use test results to confirm the fault before pricing the repair.

Related OBD Codes

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Next Steps

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