The fuel temperature sensor (FTS) is a crucial component in your vehicle’s fuel system. It monitors the temperature of the fuel and sends the information to the engine control module (ECM).
If the ECM detects a malfunction in the FTS circuit, it will trigger a diagnostic trouble code (DTC) P0186.
This article will explain what the P0186 code means, what causes it, and how to diagnose and fix the issue.
What is the P0186 Code?
The P0186 code indicates that there is a malfunction in the circuit of the fuel temperature sensor B.
This code is specific to vehicles with a second fuel temperature sensor, also known as the B sensor.
The B sensor is usually located in the fuel tank and is responsible for measuring the temperature of the fuel in the tank.
When the ECM detects a malfunction in the FTS circuit, it will trigger the P0186 code and turn on the check engine light. The code indicates that there is an issue with the FTS circuit, which could be caused by a faulty sensor, damaged wiring, or a malfunctioning ECM.
What Causes the P0186 Code?
There are several possible causes of the P0186 code, including:
- Faulty Fuel Temperature Sensor: The FTS may be faulty, causing it to send incorrect or no temperature readings to the ECM.
- Damaged Wiring: The wiring that connects the FTS to the ECM may be damaged or corroded, causing a loss of signal or incorrect readings.
- Malfunctioning ECM: The ECM may be malfunctioning, causing it to misinterpret the readings from the FTS.
- Fuel Contamination: Contaminants in the fuel, such as water or debris, can cause the sensor to malfunction.
How to Diagnose the P0186 Code?
To diagnose the P0186 code, follow these steps:
Use an OBD-II scanner to retrieve the code and freeze frame data.
- Inspect the fuel temperature sensor wiring and connector for damage or corrosion.
- Test the fuel temperature sensor using a multimeter to ensure that it is within the specified resistance range.
- Check for fuel contamination by inspecting the fuel for debris or water.
- Check the ECM for any related fault codes and perform a diagnostic scan to ensure that it is functioning correctly.
How to Fix the P0186 Code?
The following are some possible ways to fix the P0186 code:
- Replace the Fuel Temperature Sensor: If the FTS is faulty, replace it with a new one.
- Repair or Replace Wiring: If the wiring is damaged or corroded, repair or replace it.
- Clean Fuel System: If fuel contamination is the cause of the issue, clean the fuel system and replace the fuel filter.
- Replace ECM: If the ECM is malfunctioning, replace it with a new one.
In conclusion, the P0186 code is a common issue that affects vehicles with a second fuel temperature sensor. The code indicates a malfunction in the FTS circuit, which could be caused by a faulty sensor, damaged wiring, or a malfunctioning ECM. To diagnose and fix the issue, follow the steps outlined in this article. Always remember to use caution when working with fuel systems and ensure that you follow all safety precautions.
- Can I still drive my vehicle with the P0186 code?
It is not recommended to drive your vehicle with the P0186 code, as it could cause further damage to your vehicle’s fuel system.
- How much does it cost to fix the P0186 code?
The cost to fix the P0186 code will vary depending on the cause of the issue. It could range from a simple repair to a more costly replacement of components.
- How long does it take to fix the P0186 code?
The time it takes to fix the P0186 code will depend on the cause of the issue and the complexity of the repair.
- Can I fix the P0186 code myself?
If you have experience working with fuel systems and have the necessary tools, you may be able to fix the P0186 code yourself. However, it is recommended that you seek the help of a professional mechanic.
- How can I prevent the P0186 code from recurring?
Regular maintenance of your vehicle’s fuel system, such as changing the fuel filter and ensuring that the fuel is clean, can help prevent the P0186 code from recurring.