P0117 Technical Description
Engine Coolant Temperature (ECT) Sensor Circuit Low Input
If you’re seeing the P0117 trouble code, this guide will explain its meaning, symptoms, causes, and fixes. We’ll help you get your car back in shape quickly and effectively.
I’ve fixed this issue countless times, so you’re in good hands.
In this article, we’ll specifically discuss common symptoms like poor fuel economy and what tools you’ll need to diagnose and fix the problem.
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Key Takeaways
- P0117 indicates a low input from the Engine Coolant Temperature (ECT) sensor.
- Common symptoms include a check engine light, poor fuel economy, and hard starting in cold conditions.
- Causes range from a faulty ECT sensor to low coolant levels or damaged wiring.
- Diagnosing involves checking the sensor, wiring, coolant levels, and possibly the ECM.
- Fixes include replacing the ECT sensor, repairing wiring, topping up coolant, and testing the ECM.
- Addressing this issue promptly ensures optimal engine performance and prevents further problems.
Table of ContentsShow
What Does P0117 Trouble Code Mean?
The P0117 trouble code signals an issue with the Engine Coolant Temperature (ECT) sensor circuit.
Specifically, it indicates that the sensor is reading a voltage level lower than expected, suggesting that the engine coolant temperature is abnormally low.
Your vehicle’s ECT sensor plays a crucial role in monitoring the engine’s temperature.
The sensor sends this data to the engine control module (ECM), which uses it to adjust the fuel injection and ignition timing.
Accurate temperature readings ensure the engine runs efficiently and prevents overheating.
When the ECM receives a signal that the coolant temperature is excessively low, it can cause various problems.
The most common symptom is the check engine light turning on. You might also experience poor fuel economy because the ECM may enrich the fuel mixture, thinking the engine is cold.
In colder weather, you could have difficulty starting your car since the ECM relies on accurate temperature readings to optimize starting conditions.
Low voltage readings from the ECT sensor can be caused by several factors. A faulty ECT sensor is the most common culprit.
Damaged wiring or connectors leading to the sensor can also cause incorrect readings. Additionally, low coolant levels or issues within the ECM itself might trigger this trouble code.
In summary, the P0117 code means your ECT sensor is providing a voltage reading that’s too low, leading the ECM to believe the engine coolant is colder than it actually is.
This affects engine performance and can lead to other issues if not addressed promptly.
P0117 Trouble Code Symptoms
When the P0117 code is triggered, you might notice several symptoms indicating an issue with your engine coolant temperature sensor:
- Check engine light is on
- Poor fuel economy
- Hard starting in cold conditions
- Engine overheating
- Rough idle
- Increased emissions
P0117 Trouble Code Causes
Several factors can trigger the P0117 trouble code in your vehicle:
- Faulty ECT sensor
- Damaged wiring or connectors
- Low coolant level
- Corroded sensor terminals
- ECM issues
- Short circuit in the sensor wiring
How To Fix A P0117 Trouble Code
To fix a P0117 trouble code, follow these steps to diagnose and repair the issue:
1. Check Engine Coolant Temperature (ECT) Sensor
Locate the ECT sensor, usually found near the thermostat housing or on the engine block. Inspect the sensor for any visible damage or corrosion.
2. Test the ECT Sensor
Use a multimeter to measure the resistance of the ECT sensor. Compare the readings with the manufacturer’s specifications. If the resistance is outside the specified range, replace the sensor.
3. Inspect Wiring and Connectors
Examine the wiring harness and connectors leading to the ECT sensor. Look for any signs of damage, such as frayed wires or loose connections. Repair or replace any damaged wiring.
4. Check Coolant Levels
Ensure the coolant level is adequate and that there are no leaks in the cooling system. Low coolant levels can cause incorrect temperature readings.
5. Test the Thermostat
A stuck thermostat can cause the engine to run at incorrect temperatures. Check the thermostat’s operation and replace it if necessary.
6. Examine the ECM
If all other components are functioning correctly, the Engine Control Module (ECM) may be faulty. Diagnosing ECM issues can be complex, so consider consulting a professional mechanic.
7. Clear the Code and Test Drive
After making any necessary repairs, use an OBD-II scanner to clear the P0117 code. Take the vehicle for a test drive to ensure the issue is resolved and the code does not reappear.
By following these steps, you can diagnose and fix the problem causing the P0117 trouble code, ensuring your vehicle’s engine temperature is correctly monitored and maintained.
Conclusion
Now that you know what the P0117 trouble code means and how to fix it, you’re ready to tackle the problem head-on.
Have you ever dealt with this trouble code before?
Drop a comment below with your experience or any tips you have!
