P CODES (POWERTRAIN) P0100 - P0199 P0187

    Comprehensive Guide to Diagnosing and Repairing P0187 Fuel Temperature Sensor B Circuit Low Input: Boost Engine Performance and Fuel Efficiency

    Definition of Trouble Code P0187

    Trouble code P0187 refers to "Fuel Temperature Sensor B Circuit Low Input." This error code is generated when the Powertrain Control Module (PCM) detects an abnormally low signal from the Fuel Temperature Sensor B. This sensor plays a vital role in monitoring the temperature of the fuel in the fuel system and assists in optimizing engine performance and fuel efficiency.

    Diagnosing Trouble Code P0187

    Before starting the diagnostic process, gather the necessary tools, such as a digital multimeter, OBD2 scanner, and repair manual. Follow these steps to diagnose the P0187 trouble code:

    Step 1: Read the trouble codes

    Connect the OBD2 scanner to the vehicle's diagnostic port and turn on the ignition. Read the stored trouble codes and note any additional codes that may be related to the P0187 error.

    Step 2: Visual inspection

    Inspect the wiring and connectors around the fuel temperature sensor for signs of damage, corrosion, or wear. If any issues are found, repair or replace the damaged components.

    Step 3: Test the Fuel Temperature Sensor B

    Locate the fuel temperature sensor using the repair manual for your specific vehicle. With the ignition off, disconnect the electrical connector from the sensor. Using a digital multimeter, measure the resistance across the sensor terminals and compare it to the manufacturer's specifications. If the resistance is out of the specified range, replace the sensor.

    Step 4: Test the wiring and connectors

    Using the digital multimeter, check for continuity between the sensor connector and the PCM connector. If there is no continuity or high resistance, repair or replace the wiring as needed. Additionally, check for voltage at the sensor's connector with the ignition on. If the voltage is too low, there may be a problem with the PCM or the wiring to the PCM.

    Repairing Trouble Code P0187

    After diagnosing the P0187 trouble code, follow these steps to repair the issue:

    Step 1: Repair or replace damaged components

    If the diagnosis process revealed any damaged wiring, connectors, or the fuel temperature sensor itself, repair or replace the components as needed.

    Step 2: Clear the trouble codes

    Once the repairs are complete, use the OBD2 scanner to clear the stored trouble codes from the PCM.

    Step 3: Test drive the vehicle

    Take the vehicle for a test drive to ensure the issue has been resolved. Monitor the OBD2 scanner to confirm that the P0187 trouble code does not return.


    Trouble code P0187 is related to the Fuel Temperature Sensor B Circuit Low Input. Properly diagnosing and repairing this issue is crucial for optimal engine performance and fuel efficiency. Follow the step-by-step guide provided to diagnose, repair, and clear the trouble code. Regular maintenance and inspections can help prevent this error code from reoccurring in the future.

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