Published June 7, 2021

Keypad Immobiliser

Keypad (PIN -based) immobiliser as an extension of existing touch-sensor immobiliser.

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Story

My car has a built-in immobiliser, which works with a touch sensor. This means that before I start the engine, I need to touch two hidden metal surfaces in the car.

This is cool, but I do not want to tell the car wash guys (or the repairman) how they can turn on the engine, so I created an extension for it. You need to enter a 4-digit PIN code, then press the asterisk. If the PIN code was correct, then a relay connects the two points, and you can start the engine (within 15 seconds).

This is how it looks like:

My car has a built-in case under the steering wheel, which I used to host the PIN keypad.

Wiring is hidden, and it is only installed when I take the car to car wash or car repair shop