Inertia Switch (Fuel Pump Cut-off Switch)
An inertia switch cuts power to the fuel pump in a crash to reduce the risk of fire.
What is Inertia Switch (Fuel Pump Cut-off Switch)?
It reacts to a sudden impact. A hard knock or pothole can occasionally trip it. Many have a reset button. Modern cars often cut the pump through the airbag control unit instead. Repeated tripping without a crash can point to a faulty switch. It is usually in the boot, footwell or near the fuel pump.
How it works
A weight or ball moves on impact and opens the contacts.
Why it matters for your car
Check for fuel leaks before resetting it. Find its location in the handbook.
Other terms
- A/C Compressor Clutch
- API Oil Specification
- Boot Capacity (Cargo Volume)
- Brake Pad
- Carbon Cleaning (Intake Decarbonising)
- Chrome Plating
- Clutch Release Bearing
- EGR Valve
- Flywheel
- Headliner (Roof Lining)
- Instrument Cluster
- Panoramic Roof (Glass Roof)
- Piston Pin (Wrist Pin, Gudgeon Pin)
- Range Estimate (Guess-o-Meter)
- Remanufactured Parts
- Steering Rack
- Sunroof Drain
- Toe (Alignment)
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- Wheel Arch Rust