The clutch switch, also known as a clutch sensor, is a safety device on most modern manual transmission vehicles. Its purpose is to prevent the engine from starting while the vehicle is in gear. The switch is normally mounted on the clutch pedal, but it may also be located on the clutch master pushrod.
When the clutch pedal is not pushed in, the clutch switch is open and the circuit cannot be completed. If the circuit is not complete, the vehicle cannot be started. Once you depress the clutch pedal, the clutch switch is closed and the circuit is complete between the ignitions key and the starter motor. This allows your vehicle to start without a problem.
On automatic transmission vehicles, they have something similar to a clutch switch called a neutral safety switch. Neutral safety switches prevent the vehicle from being started if the transmission is in any other position besides neutral or park.
The clutch switch can fail over time, and if it does, it is normally an electrical or an electrical component issue. The switch is used every time you start your vehicle, so it can wear down, or the circuit can be blown after a while. A professional mechanic will properly diagnose the issue by reading the voltage with a voltmeter along with checking for switch continuity. If it is the switch itself that has gone bad, the mechanic can replace the clutch switch while diagnosing the problem. They will make sure all the parts are working properly and there is no visible wear on the electronic components when the clutch switch is replaced.
Since the clutch switch can fail due to wear and tear, you should be aware of the symptoms that indicate it is coming to the end of its life.
Signs that your clutch switch needs to be replaced include:
- The vehicle will start when the clutch pedal is not pushed in
- The vehicle will not start at all, even with the clutch pedal is pushed all the way in
- Sometimes the vehicle starts with the clutch depressed but other times it does not
If you're noticing any of the symptoms above, make sure to have your vehicle inspected and replace the clutch switch before the vehicle becomes inoperable.
This article originally appeared on YourMechanic.com as How Long Does a Clutch Switch Last? and was authored by Valerie Johnston.