Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Clutch Interlock Switch
DESCRIPTION
The clutch interlock switch is attached to the side of the clutch master cylinder. The switch is a reed type sealed bulb potted into the switch housing. When the clutch pedal is fully depressed, a magnet on the clutch master cylinder piston closes the switch.
OPERATION
The clutch pedal position switch is used to prevent starter motor engagement until the clutch pedal is fully depressed. When the clutch pedal is fully depressed, a magnet closes the switch. The RF Hub provides a signal to the clutch interlock switch which is grounded when the switch is closed. The PCM receives the clutch interlock switch state from the RF Hub through a dedicated circuit. When the clutch pedal is released, the switch contacts open and will not allow the Powertrain Control Module (PCM) to activate the starter relay to energize the starter motor.
The Clutch Interlock Switch is different than the traditional Clutch Pedal Switches in that it only detects the interlock (pedal depressed) position. The switch input is compared to the Clutch Position Sensor signal for the correlation diagnostic. The next two graphics illustrate the correlation diagnostic pass/fail. The threshold values are approximate. The calibrations can vary between vehicles. If a correlation fault sets it will affect the ESS system in one of the following ways:
- If the fault occurs prior to an Auto/Stop, ESS will be disabled and no Auto/Stop will occur.
- If the fault occurs during an Auto/Stop with the Transmission in neutral, the vehicle will Auto/Start and ESS will then be disabled.
- If the fault occurs during an Auto/Stop with the Transmission in gear, Vehicle will not start until the shifter is moved into neutral and then ESS will be disabled.
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.