B1390 Oil Temperature Sensor Circuit Short To Ground

How to Fix B1390 Oil Temperature Sensor Circuit Short to Ground


If you’re experiencing the B1390 error code on your car, it means that there’s a problem with the oil temperature sensor circuit. This can be a frustrating issue to deal with, but fortunately, it’s something that you can fix on your own with a little bit of know-how. In this article, we’ll walk you through the steps you need to take to fix the B1390 error code and get your car running smoothly again.

What is the B1390 Error Code?

The B1390 error code is a diagnostic trouble code that indicates a problem with the oil temperature sensor circuit. This sensor is responsible for monitoring the temperature of the engine oil and sending that information to the car’s computer. When the sensor circuit is shorted to ground, it can cause the computer to think that the oil temperature is too low, which can lead to a variety of issues.

Step-by-Step Guide to Fixing the B1390 Error Code

Step 1: Locate the Oil Temperature Sensor

The first step in fixing the B1390 error code is to locate the oil temperature sensor. This sensor is typically located near the oil filter or on the side of the engine block. Consult your car’s owner’s manual or a repair manual for your specific make and model to find the exact location of the sensor.

Step 2: Disconnect the Battery

Before you start working on the sensor, it’s important to disconnect the battery to prevent any electrical shocks or damage to the car’s computer. Locate the negative battery cable and use a wrench to loosen the bolt that holds it in place. Once the cable is loose, remove it from the battery and set it aside.

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Step 3: Remove the Oil Temperature Sensor

Using a wrench or socket set, remove the bolt that holds the oil temperature sensor in place. Carefully pull the sensor out of its socket and set it aside.

Step 4: Inspect the Sensor and Wiring

Once you’ve removed the sensor, inspect it and the wiring for any signs of damage or wear. Look for frayed wires, corrosion, or other issues that could be causing the short to ground. If you find any problems, replace the damaged parts before continuing.

Step 5: Install the New Sensor

If you need to replace the sensor, install the new one in the socket and tighten the bolt to secure it in place. Make sure the wiring is properly connected and not pinched or damaged.

Step 6: Reconnect the Battery

Once you’ve finished working on the sensor, it’s time to reconnect the battery. Reattach the negative cable to the battery and tighten the bolt to secure it in place.

Step 7: Clear the Error Code

Finally, use an OBD-II scanner to clear the B1390 error code from the car’s computer. This will reset the system and allow the car to start fresh with the new sensor in place.

Tips for Preventing the B1390 Error Code

To prevent the B1390 error code from occurring in the future, it’s important to keep your car’s oil temperature sensor and wiring in good condition. Here are a few tips to help you do that:

– Regularly inspect the sensor and wiring for signs of wear or damage.
– Change your car’s oil and oil filter according to the manufacturer’s recommended schedule.
– Use high-quality oil and filters to ensure that your car’s engine is running smoothly.
– Avoid driving your car in extreme temperatures or conditions that could cause the oil temperature to fluctuate rapidly.


Fixing the B1390 error code may seem daunting, but with the right tools and knowledge, it’s something that you can do on your own. By following the steps outlined in this article, you can get your car back on the road and running smoothly in no time.


1. Can I drive my car with the B1390 error code?

It’s not recommended to drive your car with the B1390 error code, as it can cause a variety of issues with your car’s engine and performance. It’s best to fix the issue as soon as possible to avoid any further damage.

2. How much does it cost to fix the B1390 error code?

The cost of fixing the B1390 error code will depend on the make and model of your car, as well as the extent of the damage. In general, it can cost anywhere from $100 to $500 to fix this issue.

3. Can I fix the B1390 error code myself?

Yes, you can fix the B1390 error code yourself if you have the right tools and knowledge. However, if you’re not comfortable working on your car’s engine or electrical system, it’s best to take it to a professional mechanic for repairs.