Disable stop/start system in car on startup?


I'm looking to use an Arduino to disable the stop/start system in a car.

The stop/start system re-enables itself each time the ignition is turned on, but the stop/start system can be disabled with the press of a button after the car is started.

I want to automate a simple way for an Arduino to power up when the car starts, wait a few seconds, then press the "disable stop/start" button once..

Is this possible? Or is it a more complicated project then it sounds?

The code is simple, the problem will be

  • detecting the start, if it isn’t merely power up


  • operate the switch

which could be done using a relay in parallel with the contacts of the real switch.

Do you have access to the switch? If it was like a TV remote button it might be harder that a large traditional switch.


Yes it'd just be "when the Arduino gets power, wait a certain time then perform the code" so it wouldn't need to detect anything, only the time since it received power.

So it'd be a relay doing the physical switch work? Ok thanks, I'll start to look in to that. And yes I have access to the button, so I'd probably just be accessing the switch +/- from underneath and intercepting them to add the Arduino bits.

Yes, bridging the switch, if it’s just a normally open pushbutton kinda thing, is the trick.

And using a relay is entirely safe, as there will be total electric isolation between the Arduino and the switch, so it won’t matter how the switch is connected.

We can further assume, but I suppose with something like a car it would be prudent to know, that the switch is not handling a great deal of current; it shouldn’t have to, so any small relay will do.

For the relay, it is probably most expedient to us a pre-built relay module meant for the Arduino. Google is your friend here.

Powering the Arduino is simple enough also, for testing a cigarette lighter cell phone charger can be used to power the Arduino and the relay board.

Later you can up the mechanical concept on aesthetic terms.

First: light an LED right away, extinguish it after the delay you want. No need to tinker with the switch before you get the software (such as it is) working.


Thanks, that's a good tip to pre-build the circuit to light an led indoors first, like you say, I can use a phone charger to test it all indoors and and in the car also.. I'll get started on a little bit of relay research.

I've only played around with an Arduino to the extent of making a watch winder with a stepper motor and driver board... I'll have to work out the smallest Arduino I can use for this project too.

See this, there are many such items. It is of course possible to DIY your own relay with a driver circuit and use a tiny relay if you want the final thing to be smaller.

The Nano nice, you can find clones with no header pins already soldered on for a low profile. There are even smaller ones, but for ease of use I suggest staying with models that have a USB connector on them.


Thanks for the link, I'll check those relays out. You've been a great help and have pointed me in the right direction to get started.

This topic was automatically closed 120 days after the last reply. New replies are no longer allowed.