Fault code P0808 – clutch position sensor circuit high input

Fault code P0808 is called “Clutch Position Sensor Circuit High Input” but in different programs it may be called differently. This fault designation applies to all vehicles equipped with OBD-II.

Technical description and explained code P0808

If your OBD-II equipped vehicle has stored code P0808. This means that the transmission control module (PCM) has detected a high signal level in the clutch position sensor circuit. This code applies only to vehicles equipped with a manual transmission.

Fault code P0808 – clutch position sensor circuit high input

The PCM controls certain manual transmission functions. Shifter position and clutch pedal position are among these functions. In some models, turbo input and output speeds are also monitored to determine the degree of clutch slippage.

The clutch is the mechanical clutch that connects the engine to the transmission. When the clutch master cylinder is depressed, hydraulic fluid is pushed into the slave cylinder. The slave cylinder actuates the clutch pressure plate. Allowing you to engage and disengage the engine from the transmission as needed.

The main function of the clutch switch is to act as a safety feature to prevent the engine from starting when the transmission is inadvertently engaged. The PCM and other controllers also use input from the clutch switch for various engine control calculations. These include automatic braking functions, as well as for implementing hill hold.

Diagnostic code DTC P0808 is set when the PCM or TCM detects a high voltage or resistance signal level in the clutch position sensor circuit. The engine warning lamp or transmission warning lamp will also illuminate.

Symptoms of vehicle malfunctions

The main signal that an error P0808 has occurred is the Malfunction Indicator Lamp (MIL) is also known as the CheckEngine Light.

It can also be warning signs such as:

  1. Check engine control lamp on the control panel will light up (the code will be recorded in the memory as a malfunction).
  2. Poor engine starting.
  3. In some cases, the engine may not start even if the clutch pedal is fully depressed.
  4. In rare cases there may be no symptoms at all.

Stored code P0808 can cause various vehicle control, safety and traction functions to fail. For this reason, this error should be considered serious.

Factors that can cause this error code

The error code P0808 can mean that one or more of the following problems have occurred:

  • Faulty clutch position sensor.
  • Improperly adjusted clutch switch.
  • Short-circuited, broken wiring or connectors in clutch position sensor circuit.
  • Poor electrical connection in circuit.
  • Fuse or fusible link blown.
  • Faulty PCM or other control module, also possible programming error.

How to fix or reset OBD-2 code P0808

Some suggested steps for troubleshooting and fix the error code P0808:

  1. Inspect the wiring for damage, abrasions, breaks, and shorts. If wiring is damaged, repair or replace it.
  2. Clear any diagnostic trouble codes from the PCM, and perform a test drive to see if diagnostic trouble code P0808 returns.
  3. Check the clutch position sensor, replace if necessary.
  4. Check the fuse or fusible link.
  5. If all is correct, the PCM may need to be replaced and reprogrammed.

Diagnose and repair of problems

To rule out all variants of error P0808, visually inspect the wiring to the clutch position sensor. Check all system fuses and replace blown ones if necessary. Also check the battery under load, cable connections, and alternator power.

Locate the diagnostic connector, plug in the scanner and get all the stored codes and data. Write this information down, as it may help you in further diagnosis. Delete the codes and test-drive the vehicle to see if code P0808 appears again after resetting.

Test the voltage

Check the voltage on the clutch position sensor input circuit. If there is voltage in the input circuit, depress the clutch pedal and check the voltage in the output circuit. If there is no voltage on the output circuit, the sensor may be defective.

When voltage is present on both sides of the sensor and the pedal is depressed, check the input circuit on the PCM. If the input signal to the PCM is present, there may be a faulty PCM or programming error.

If no clutch position sensor input signal is present at the PCM connector, disconnect all associated controllers. Use a multimeter to check the resistance for all circuits in the system. If necessary, repair or replace closed or open circuits.

It is a good idea to check the system fuses when the clutch pedal is depressed, if error P0808 is present. Fuses that may seem normal when first tested may fail when the circuit is under load.

Often a worn clutch hinge arm or clutch pedal bushing can be misdiagnosed as a faulty clutch position sensor.

On which vehicles does this problem occur most frequently

Fault code P0808 can occur on different vehicles but there are statistics on which brands this occurs most often. Here is a list of some of them:

  • Chevrolet (Cruze)
  • Chrysler
  • Citroen
  • Dodge
  • Ford (Focus)
  • Jeep
  • Land Rover
  • Mercedes-Benz
  • Opel (Antara, Insignia)
  • Peugeot
  • Smart
  • Toyota (Auris, Corolla, Verso)

Fault code P0808 can sometimes be found with other errors. The most common are the following: P0805, P0806, P0807, P0809, P080A.

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