P0116 - Engine Coolant Temperature Circuit Range/Performance

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

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Related Inspection

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

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Likely Repairs & Cost Guides

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Related OBD Codes

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Next Steps

Move from code lookup to diagnosis, then estimate the likely repair only after symptoms, causes, and checks point to the same path.