P0900 – Clutch Actuator Circuit / Open (OBD2)
P0900 means "Clutch Actuator Circuit / Open". The control unit sees an open circuit: the electrical connection to the clutch switch / clutch position system is interrupted, so no current can flow when the component is commanded or read.
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P0900 quick summary
| Fault code | P0900 |
|---|---|
| Meaning | Clutch Actuator Circuit / Open |
| System | Powertrain (Engine & Transmission) |
| Vehicles | Generic OBD2 |
| Severity | Medium |
| 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.
On VAG vehicles (VW, Audi, Škoda, Seat, Cupra), VCDS and older VAG testers can show this code as the five-digit VAG code 17284 (P0900). Both numbers mean the same fault.
Symptoms of P0900
- 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 P0900 (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.Unplugged, loose or corroded connector
Most likelyOften after previous repair work in the area.
2.Broken wire in the harness
Typical at bends, near the engine mounts and where the harness rubs on brackets.
3.Burnt-out winding or internal break in the clutch switch / clutch position system
4.Faulty or misadjusted clutch pedal switch
5.Faulty clutch position sensor
6.Worn clutch (slip codes)
7.Clutch actuator fault (automated manual)
Step-by-step diagnostic guide
- 1
Read codes and switch status
Read codes and watch the clutch switch or position signal in live data while pressing the pedal.
- 2
Measure resistance and continuity
Unplug the clutch switch / clutch position system and measure its resistance across the terminals. An infinite (OL) reading confirms an internal break. If the component is fine, check each wire back to the control unit for continuity.
Multimeter: Solenoids and heaters typically read a few ohms to a few dozen ohms; "OL" means open. Wire continuity: below about 1 Ω.
- 3
Check switch adjustment
Check the switch position on the pedal bracket and the pedal stop.
- 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
Check the clutch
For slip codes, check the clutch for wear and the actuator for leaks or faults.
- 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 P0900?
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 P0900?
Typical repair costs are 15 € – 1500 €, depending on the cause and the vehicle. The most common fixes are: unplugged, loose or corroded connector; broken wire in the harness; burnt-out winding or internal break in the clutch switch / clutch position system. 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 P0900 and similar codes?
P0900 belongs to a group of codes for the same component that differ in the type or location of the fault: P0833 – Clutch Pedal Switch B Circuit; P0834 – Clutch Pedal Switch B Circuit Low; P0835 – Clutch Pedal Switch B Circuit High; P0901 – Clutch Actuator Circuit Range/Performance; P0902 – Clutch Actuator Circuit Low; P0903 – Clutch Actuator Circuit High. 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.