How to Resolve P0118 Trouble Code?

[LeChristopher]

Here are the solutions for the P0118 trouble code: 1. Move or shake the related wiring harness or connectors and observe the sensor signal on the diagnostic tool or oscilloscope. 2. If the fault occurs, the diagnostic tool will show corresponding changes, which can help locate the intermittent fault. 3. If the sensor circuit is shorted to the positive battery voltage, both the ECM and the sensor may be damaged. 4. After troubleshooting the car, the trouble code must be cleared. 5. When clearing the trouble code, strictly follow the specified clearing method for the specific vehicle model. Never use the method of disconnecting the battery's negative terminal to clear the car's trouble code.

[LaJessica]

The P0118 trouble code usually indicates a high input in the engine coolant temperature sensor circuit. When I encountered this issue, my first reaction was to check the coolant level to ensure it wasn't low, as it affects the sensor's readings. Then, I inspected the sensor connector for looseness or corrosion, and used a multimeter to measure the resistance value. Normally, it should vary between 5kΩ and 25kΩ. If the reading is too high or infinite, I would consider replacing the sensor. A short circuit to the power line can also cause a high input, so it's necessary to inspect the wiring harness for any worn sections and repair them. After addressing the issue, it's essential to drive for a while to verify that the trouble code clears. Otherwise, engine overheating or increased fuel consumption could damage the vehicle. When doing DIY repairs, be careful not to burn yourself—safety first.

[Darin]

The P0118 light came on in my car. I first simply topped up the coolant, but the light remained on. I then popped the hood and tried pressing the sensor connector tight, which fixed the issue. If that doesn't work, just buy a new sensor and replace it—it's only about a hundred bucks online. Circuit issues like broken or shorted wires can also trigger it, in which case you'd need to solder the wiring harness. Don't delay too long, as fuel consumption will increase. After parking, feel if the engine is running hotter than usual to verify if the problem is resolved—saves money and hassle.

[DeEmerson]

P0118 fault code means the coolant sensor reading is too high. Check the coolant reservoir immediately to see if it's full; if not, top it up. The sensor is usually located at the corner of the engine. Unplug the connector to check for dirt or looseness. If unsure, clear the code and try again. Generally, replacing the sensor solves the issue. Avoid driving with an overheated engine, and it's safer to have someone help test it.