Code P0117 on the 2024 Ford Maverick indicates the Engine Coolant Temperature (ECT) sensor signal is below the expected range - essentially reading too cold. This could indicate an actual sensor fault, wiring issue, or in rare cases, actual overcooling of the engine.
ECT Sensor Function
The coolant temperature sensor is critical for engine management. The ECM uses this data to adjust fuel injection (richer when cold), ignition timing, idle speed, and cooling fan operation. Incorrect temperature readings cause poor fuel economy, rough running, and can prevent proper warmup.
Low Input Explained
The ECT sensor is a thermistor - resistance changes with temperature. Cold temperatures produce high resistance and low voltage signal. P0117 means the signal indicates very cold temperature even when the engine is warm. This can occur from sensor failure, short to ground in the circuit, or connector issues.
Symptoms
With P0117, the engine may run rich constantly (ECM thinks it's always cold), fuel economy decreases, the temperature gauge may read cold or erratic, and the cooling fan may not operate correctly. Extended cranking may occur if the ECM's fuel strategy is wrong.
Common Causes
Sensor failure is most common - the internal thermistor develops issues causing incorrect resistance. Wiring shorted to ground creates low voltage readings. Connector corrosion or coolant contamination at the sensor can cause problems. On the Maverick's hybrid version, different sensors may be used.