Fault code P0116 – a step-by-step guide to diagnosing and fixing it

Error code P0116 is displayed and the check engine light is on - what does this mean?

DTC P0116 is recognized by the OBD system when the coolant temperature sensor (ECT) sends a signal outside the expected range. This fault code indicates a problem with the temperature sensor or its circuit. For various manufacturers, this trouble code may also be referred to as "Engine Coolant Temperature Circuit Range/Performance Problem".

What can cause this error code?

• Defective coolant temperature sensor (ECT sensor)
• Damaged or corroded sensor cable
• Loose or corroded plug connections
• Defective thermostat
• Low coolant level
• Air bubbles in the cooling system
• Defective engine control unit (ECU)
• Short circuit in the sensor cable

What symptoms occur in parallel with fault code P0116?

• Starting problems: The vehicle starts poorly or requires several attempts
• Uneven idling: The engine runs unevenly at idle speed
• Increased fuel consumption: Consumption increases noticeably
• Poor engine performance: Loss of power, especially when the engine is cold
• Overheating indicator: Incorrect temperature display on the dashboard
• Fan problems: Radiator fan runs permanently or not at all

How can the problem with error code P0116 be resolved?

• Repairing this EOBD code requires a systematic diagnosis of the cooling system components.
• Replace the coolant temperature sensor completely and clean the plug connection
• Check sensor cable for damage and replace defective lines
• Replace the thermostat and bleed the cooling system completely
• Check the coolant level and top up to the correct level
• Clean plug connections on the ECT sensor and check for tight fit
• Flush the entire cooling system and remove air bubbles
• Check engine control unit for defects and replace if necessary