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P0704 – Clutch Switch Input Circuit Malfunction (OBD2)

P0704 means "Clutch Switch Input Circuit Malfunction". The control unit has detected a fault in the electrical circuit of the clutch switch / clutch position system: the signal or control current is missing or outside the expected window. The code does not say whether the value is too high or too low, so the wiring and the component itself both have to be checked.

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P0704 quick summary

Fault codeP0704
MeaningClutch Switch Input Circuit Malfunction
SystemPowertrain (Engine & Transmission)
VehiclesGeneric OBD2
SeverityMedium
Can I drive?Usually yes, but the engine may not start, cruise control and start-stop may not work. With excessive clutch slip, avoid heavy loads.
Repair cost€15 – €1,500

How clutch switches and clutch position sensors work

Clutch pedal switches and clutch position sensors tell the control units when the clutch is pressed – for starting, cruise control, start-stop and automated clutches; these codes cover them and the clutch actuator.

Manual cars have one or two clutch pedal switches (A, B) or a position sensor on the pedal. They allow the engine to start only with the clutch pressed, cancel cruise control, control start-stop and smooth engine speed during gear changes.

Automated manual and some dual-clutch systems use a clutch actuator and a clutch position sensor; codes P0805–P0811 and P0900–P0903 cover their position sensing, control error and excessive slip.

A faulty clutch switch can stop the engine from starting, disable cruise control or start-stop, and cause jerky behaviour when changing gear.

Symptoms of P0704

  • Engine does not start even with the clutch pressed
  • Cruise control or start-stop not working
  • Engine speed flare when changing gear
  • Clutch slipping (automated clutches)
  • Check Engine light on

Most common causes of P0704 (most likely first)

Mechanic's Pro Tip

On automated manual gearboxes, always run the clutch learning routine after any clutch, actuator or battery work – most 'clutch slip' complaints after repairs come from a missing calibration.

  1. 1.Damaged wire or loose, corroded connector at the clutch switch / clutch position system

    Most likely

    Green or white corrosion, pushed-back pins and chafed insulation near hot or moving parts are the most common findings.

  2. 2.Faulty clutch switch / clutch position system

    An internal break or short in the component itself.

  3. 3.Blown fuse or missing supply voltage

    If several codes appeared at the same time, check the shared fuse, relay or ground point first.

  4. 4.Worn clutch (slip codes)

  5. 5.Clutch actuator fault (automated manual)

Step-by-step diagnostic guide

  1. 1

    Read codes and switch status

    Read codes and watch the clutch switch or position signal in live data while pressing the pedal.

  2. 2

    Check the circuit with a multimeter

    With the ignition off, unplug the clutch switch / clutch position system and the control unit connector (or back-probe), then check each wire between them for continuity and for shorts to ground and to battery voltage. Compare the component's resistance or supply voltage with the value in the repair manual.

    Multimeter: Wire continuity: below about 1 Ω. Wire to ground with both connectors unplugged: no continuity. Supply/reference with ignition on: usually 5 V for sensors, battery voltage for actuators.

  3. 3

    Check switch adjustment

    Check the switch position on the pedal bracket and the pedal stop.

  4. 4

    Measure the switch or sensor

    Check the switch contacts or sensor voltage over the pedal travel.

    Multimeter: Position sensors: signal changing smoothly across the travel (for example about 0.5–4.5 V).

  5. 5

    Check the clutch

    For slip codes, check the clutch for wear and the actuator for leaks or faults.

  6. 6

    Replace and calibrate

    Replace the faulty part and run the clutch or actuator calibration with the scan tool if required.

Frequently asked questions

Can I keep driving with P0704?

Usually yes, but the engine may not start, cruise control and start-stop may not work. With excessive clutch slip, avoid heavy loads.

How much does it cost to fix P0704?

Typical repair costs are 15 € – 1500 €, depending on the cause and the vehicle. The most common fixes are: damaged wire or loose, corroded connector at the clutch switch / clutch position system; faulty clutch switch / clutch position system; blown fuse or missing supply voltage. Always confirm the cause with the tests above before buying parts.

Why won't my car start with the clutch pressed?

If the clutch switch does not report 'pressed', the starter is blocked for safety.

Can a clutch switch affect cruise control?

Yes. Cruise control switches off when the clutch is pressed, so a faulty switch can disable it.

What is the difference between P0704 and similar codes?

P0704 belongs to a group of codes for the same component that differ in the type or location of the fault: P0805 – Clutch Position Sensor Circuit Malfunction; P0806 – Clutch Position Sensor Circuit Range/Performance Malfunction; P0807 – Clutch Position Sensor Circuit Low Malfunction; P0808 – Clutch Position Sensor Circuit High Malfunction; P0809 – Clutch Position Sensor Circuit Intermittent Malfunction; P0810 – Clutch Position Control Error. The tests on this page apply to the whole group; the type of fault tells you where to start.

Related fault codes

This guide is for information only. Working on vehicles can be dangerous — if you are unsure, have the car checked by a qualified mechanic. Values can differ between model years; always check the manufacturer's repair information.