P0185 Fuel temperature sensor “B” circuit malfunction
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P0185 – OBD-II Trouble Code Technical Description
Trouble code P0185 indicates a fault in the fuel temperature sensor “B” circuit.
What does the fault code mean P0185?
Trouble code P0185 indicates a problem with the fuel temperature sensor “B” or its circuit. This sensor monitors the temperature of the fuel in the fuel tank or fuel system. When the ECM (Engine Control Module) detects that the signal from fuel temperature sensor “B” is outside the expected range, it sets DTC P0185.
Possible reasons
Some possible reasons for the P0185 trouble code:
- Fuel temperature sensor “B” malfunction: The sensor itself may be damaged or have an electrical connection problem.
- Sensor Circuit Open or Shorted: The wires connecting the sensor to the Engine Control Module (ECM) may be damaged, open, or shorted.
- ECM Problems: The Engine Control Module may have defects or malfunctions that prevent it from communicating with the fuel temperature sensor “B”.
- Incorrect electrical connection: Poor connections, oxidation or other problems with the electrical connection between the sensor and the ECM can cause the error.
- Incorrect Fuel Temperature: Sometimes the fuel temperature itself can be unusual due to problems in the fuel system or the environment.
What are the symptoms of a fault code? P0185?
Some possible symptoms when trouble code P0185 appears:
- Deterioration in fuel economy: Because the ECM does not receive accurate fuel temperature data, it may cause the fuel/air mixture to be miscalculated, which could result in poor fuel economy.
- Power Loss: Improper fuel injection control due to incorrect fuel temperature data can result in loss of engine power.
- Unstable engine operation: The engine may become unstable, especially at low speeds or when running cold.
- Check Engine Light Appears: This error code typically causes the Check Engine light to turn on on your vehicle's dashboard.
How to diagnose a fault code P0185?
To diagnose trouble code P0185, follow these steps:
- Check connections: Check all connections to the fuel temperature sensor for corrosion, oxidation, or breaks.
- Check wiring: Inspect the wiring from the fuel temperature sensor to the engine control module (ECM) for damage, opens, or shorts.
- Check the sensor itself: Using a multimeter, check the resistance of the fuel temperature sensor at different temperatures. Compare the values obtained with the manufacturer's technical specifications.
- Check the fuel pump: If the fuel pump has a built-in fuel temperature sensor, make sure it is operating correctly.
- Check the engine control module (ECM): If all of the above components are in good condition, the problem may be with the engine control unit itself. Contact a professional for further diagnosis and repair.
It is important to note that these steps are general guidelines and may vary depending on your specific vehicle make and model.
Diagnostic errors
When diagnosing DTC P0185, the following errors may occur:
- Insufficient wiring check: Some technicians may skip checking the wiring or fail to detect damage, corrosion, or breaks that may be causing the problem.
- Incorrect sensor testing: If the fuel temperature sensor is not tested correctly or is not tested at different temperatures, it may lead to incorrect conclusions.
- Fuel pump malfunctions: If the fuel temperature sensor is integrated into the fuel pump, misdiagnosis or incorrect testing of this component may lead to erroneous conclusions.
- Engine control module (ECM) malfunctions: Some technicians may miss the possibility of a faulty ECM itself as the source of the problem.
- Lack of comparison of results with technical specifications: It is important to compare the obtained values with the manufacturer's technical specifications in order to correctly interpret the test results.
To avoid these mistakes, it is important to carefully follow the diagnostic manual, use the correct equipment and testing methodology, and seek additional resources or professionals when necessary.
How serious is the fault code? P0185?
Trouble code P0185 indicates potential problems with the fuel temperature sensor. While this code is not critical in itself, it can cause the engine to malfunction and reduce vehicle performance. For example, improper control of the fuel injection system can result in inefficient fuel combustion and increased fuel consumption, as well as poor exhaust emissions. If a P0185 code occurs, it is recommended that the problem be diagnosed and repaired as soon as possible to avoid further engine damage and reduced vehicle performance.
What repair will help eliminate the code? P0185?
Troubleshooting DTC P0185 may require the following:
- Replacing the fuel temperature sensor: If the sensor is truly faulty and is unable to transmit the correct signals to the engine control module, then it should be replaced.
- Checking and Repairing Wiring: Sometimes the problem may be due to damaged or broken wiring connecting the fuel temperature sensor to the engine control module. Check wiring for corrosion, breaks or damage and replace or repair if necessary.
- Checking and replacing fuses and relays: Check the condition of the fuses and relays that control the fuel temperature sensor circuit. If necessary, replace damaged elements.
- Diagnosis of other components: Sometimes the problem may be related to other components of the fuel injection or engine management system. Check other sensors and systems for faults and make necessary repairs or replacements.
- Re-diagnosis: After performing repairs or replacing components, re-test with specialized equipment to ensure that the problem has been completely resolved and that DTC P0185 no longer appears.
P0185 – Brand-specific information
DTC P0185 information may vary depending on vehicle manufacturer and diagnostic system used? Some possible decodings for different brands:
- Ford: Fuel temperature sensor “B” is out of range.
- Chevrolet / GMC: Fuel temperature sensor “B” – high input.
- Toyota: Fuel temperature sensor - signal too high.
- Honda: Fuel temperature sensor “B” – low signal voltage.
- Volkswagen: Fuel temperature sensor “B” – signal too high.
- BMW: Fuel temperature sensor “B” – signal too high.
Check with your specific vehicle make to get a more accurate description of the P0185 trouble code for your vehicle.
