P0117: Engine coolant temperature sensor circuit low input
Can I drive with P0117?
Yes, but drive carefully and get it checked soon. The sensor reports extreme boiling heat (short circuit), causing electric fans to roar and lean running.
What does P0117 mean?
P0117 stands for Engine Coolant Temperature Circuit Low Input.
Symptoms you may notice
- Cabin heater blows lukewarm or cool air in cold weather
- Dashboard temperature gauge stays near cold or fluctuates
- Radiator cooling fans running at high speed continuously
- Decreased gas mileage due to prolonged engine warm-up
How much does it cost to fix?
Repair costs for code P0117 depend on the specific underlying root cause, ranging from simple DIY checks to component replacement. The table below lists the most common causes and rough price ranges in USD:
- Short to ground in ECT sensor signal wire
- Internally shorted coolant temperature sensor
- Corrosion or moisture in sensor connector
- Damaged harness near hot exhaust parts
What to do next
- Unplug the ECT sensor connector; if temperature drops to -40° on scanner, the sensor is shorted.
- Inspect wiring insulation along the cylinder head and engine block.
- Replace the coolant temperature sensor and refill lost coolant.
Related codes
About this code
P0117 indicates low voltage (typically below 0.2V), which translates to a false coolant reading of over 284°F (140°C). While the vehicle may still drive, the cooling fans may run at maximum speed continuously and hot restarting can be prolonged. It is important to confirm whether the engine is truly overheating before continuing to drive.