P0656 Fuel level sensor circuit malfunction

P0656 – OBD-II Trouble Code Technical Description

The P0656 code indicates that the powertrain control module (PCM) has detected an abnormal (compared to the manufacturer's specification) voltage in the fuel level output circuit.

What does the fault code mean P0656?

Trouble code P0656 indicates a problem with the fuel level output circuit. This means that the engine control module (PCM) has detected abnormal voltage in the circuit responsible for monitoring the fuel level in the tank. Low or high voltage can indicate a variety of problems, such as a faulty fuel sensor, wiring or connection problems, or even a faulty PCM itself.

Possible reasons

Possible causes of DTC P0656:

• Faulty fuel level sensor: The fuel level sensor may be faulty, causing the fuel level to be read incorrectly and causing the P0656 trouble code to appear.
• Problems with wiring and connections: Poor connections, corrosion, or breaks in the wiring between the fuel level sensor and the engine control module (PCM) can cause erroneous data and cause a P0656 code.
• Defective PCM: If the PCM, which controls engine functions, has a malfunction or malfunction, this can also cause the P0656 code to appear.
• Power problems: Unstable or insufficient power to the vehicle's electrical system may cause abnormal signals in the fuel level circuit and cause an error code to appear.
• Malfunctions of other components: In rare cases, the cause of the P0656 code may be other components that affect the fuel level circuit, such as relays, fuses, or additional sensors.

To accurately identify the cause, it is recommended to carry out diagnostics using appropriate equipment.

What are the symptoms of a fault code? P0656?

Symptoms when trouble code P0656 is present may vary depending on the specific cause and context:

• Fuel level indicator on the instrument panel: If the problem is with the fuel level sensor, you may notice that the fuel level indicator on the instrument panel shows an incorrect value or moves in an unexpected way.
• Fuel level instability: If the fuel level sensor does not work properly, the fuel level in the tank may become unstable, which may cause the remaining fuel level to be displayed on the instrument panel in an unpredictable manner.
• Problems with starting the engine: If the fuel level problem becomes severe, it may cause difficulty starting the engine or even engine failure.
• Unexpected engine shutdown: In some cases, if the fuel level in the tank is actually insufficient, it may cause the engine to shut down while driving.
• Error or warning on the instrument panel: Depending on the design and settings of the vehicle, you may also receive an error message or warning about fuel level problems on the instrument panel.

These are just a few of the possible symptoms that may be associated with the P0656 trouble code. It is important to note that when such symptoms appear, it is recommended to diagnose the fuel system to determine the cause and eliminate the problem.

How to diagnose a fault code P0656?

To diagnose DTC P0656, we recommend following these steps:

1. Reading the error code: Use a diagnostic scanner to read the P0656 error code and any additional error codes that may be associated with it.
2. Visual inspection: Inspect the wiring and connections associated with the fuel level sensor and PCM for damage, corrosion, or breaks. Also check for fuel leaks around the fuel level sensor.
3. Checking the fuel level sensor: Using a multimeter, check the resistance of the fuel level sensor at different fuel levels in the tank. The values ​​must comply with the manufacturer's specifications.
4. Electrical circuit check: Check the voltage and resistance in the circuit between the fuel level sensor and the PCM to ensure that the wiring and connections are OK.
5. Checking the fuel level: Make sure that the actual fuel level in the tank matches the fuel level sensor reading. Sometimes the problem may be due to the sensor itself not functioning properly.
6. Check PCM: Diagnose the PCM for errors and problems processing data from the fuel level sensor.
7. Power check: Make sure the engine control module is receiving proper power, as power problems can cause erroneous signals from the fuel level sensor.
8. Checking other components: Check other fuel system components, such as relays and fuses, for problems that may be affecting the fuel level circuit.

After all the above checks have been carried out and the cause has been identified, it is recommended to carry out the necessary repairs or replacement of components. If you are unsure of your diagnostic and repair skills, it is recommended that you contact a qualified auto mechanic or auto repair shop.

Diagnostic errors

When diagnosing DTC P0656, the following errors may occur:

• Incorrect interpretation of error code: Misunderstanding the meaning of the P0656 code may lead to incorrect diagnosis and repair. For example, if the problem is believed to be solely with the fuel level sensor, but in fact the problem lies in the electrical circuit, this may lead to a failed repair.
• Skipping Wiring and Connection Checks: Failure to perform a visual inspection correctly or skip checking the condition of wiring and connections may result in an incorrect diagnosis. The problem may be a broken wire or a bad connection that needs to be fixed.
• Faulty fuel level sensor replacement: Sometimes mechanics may assume that the problem is related only to the fuel level sensor and thoughtlessly replace it without conducting a full diagnosis. However, the cause may be in other components or in the electrical circuit.
• Ignoring other possible causes: Problems with the electrical circuit, PCM, or other fuel system components can also cause the P0656 code to appear. Ignoring these possible causes may result in unsuccessful diagnosis and repair.
• Faulty interpretation of diagnostic results: Incorrect understanding of the diagnostic results or incorrect determination of the cause of the problem can also lead to errors in diagnosing the P0656 code.

It is important to ensure that diagnostics are performed correctly and consistently, and to be prepared to test various fuel system and electrical components to accurately identify and correct the cause of the P0656 trouble code.

How serious is the fault code? P0656?

Trouble code P0656, indicating an anomaly in the fuel level output circuit, can be serious depending on the specific circumstances and the reason for its occurrence. Although this code does not indicate an immediate safety hazard on the road, it may indicate potential problems that require attention and repair. There are several reasons why a P0656 code may be serious:

• Unpredictability of fuel level: If the fuel gauge is not functioning correctly, the driver may not be able to know exactly how much fuel is left in the tank, which could result in the risk of running out of fuel at the wrong time or place.
• Possible engine problems: Incorrect fuel level readings may result in incorrect fuel consumption or insufficient fuel in the system, which may adversely affect engine operation and performance.
• Risk of other problems: If the P0656 code is ignored or not repaired promptly, it may cause additional problems with the fuel system, electrical circuit, or other vehicle components.
• Inability to pass technical inspection: In some jurisdictions, a vehicle with an active DTC may not be eligible for maintenance or inspection.

Although the P0656 trouble code may be considered less critical than some other codes, ignoring it or neglecting repairs can lead to additional problems and risks to the safety and reliability of your vehicle.

What repair will help eliminate the code? P0656?

The repair that will help resolve the P0656 fault code depends on the specific cause that caused it, several general steps to resolve the problem:

1. Replacing the fuel level sensor: If the problem is due to a faulty fuel level sensor, you will usually need to replace it with a new one that meets the manufacturer's specifications.
2. Repair or replacement of wiring and connections: Poor connections or breaks in the wiring between the fuel level sensor and the engine control module (PCM) can cause trouble code P0656 to appear. In this case, repair or replacement of the corresponding wires and connectors is required.
3. PCM Check and Repair: If the problem is due to a malfunction of the PCM itself, it may need to be diagnosed and, if necessary, repaired or replaced by the control engine module.
4. Checking and updating PCM software: In some cases, the problem may be related to the PCM software. The car manufacturer may release a firmware update that will help fix the problem.
5. Checking and replacing other components: Sometimes the cause of the P0656 code may be related to other components in the fuel system or electrical circuit. After diagnosis, these components may need to be replaced or repaired.

After diagnosing and determining the specific cause of the P0656 code, it is recommended to perform the appropriate repairs or component replacement. If you are unsure of your diagnostic and repair skills, it is recommended that you contact a qualified auto mechanic or auto repair shop.

What is P0656 Engine Code [Quick Guide]

P0656 – Brand-specific information

Deciphering the P0656 trouble code for some specific car brands:

• Volkswagen (VW):
  • P0656 – Fuel Level Sensor – Low Input. The problem may be due to a faulty fuel level sensor on Volkswagen vehicles.
• Ford:
  • P0656 – Fuel Level Sensor – Low Input. This error code indicates problems with the fuel level sensor on Ford vehicles.
• Chevrolet:
  • P0656 – Fuel Level Sensor – Low Input. This code indicates problems with the fuel level sensor on Chevrolet vehicles.
• Toyota:
  • P0656 – Fuel Level Sensor – Low Input. The problem may be related to the fuel level sensor on Toyota vehicles.
• BMW:
  • P0656 – Fuel Level Sensor – Low Input. The problem may arise from the fuel level sensor on BMW vehicles.
• Mercedes-Benz:
  • P0656 – Fuel Level Sensor – Low Input. The problem may be related to the fuel level sensor on Mercedes-Benz vehicles.
• Honda:
  • P0656 – Fuel Level Sensor – Low Input. The problem may be related to the fuel level sensor on Honda vehicles.
• Audi:
  • P0656 – Fuel Level Sensor – Low Input. The problem may arise from the fuel level sensor on Audi cars.
• Hyundai:
  • P0656 – Fuel Level Sensor – Low Input. The problem may be related to the fuel level sensor on Hyundai vehicles.

These are just a few examples of how the P0656 code may appear on different makes of vehicles. It is recommended to refer to the specifications and documentation of your specific model for a more accurate interpretation of the error code.