Remote vehicle ignition

Hi there! Some might remember me from around 7 months ago, i had an idea to make a remote vehicle ignition that could start a car via txt message.

Well, some months on i've pretty much finished the project, and all runs well in my EFI car and has done for months without a hitch.

I've got a friend who has an old toyota hilux and wants me to install one, the problem being this: The way my prototype works is, it receives the ignition code/pin via text message through the GSM board, then checks to see whether the car is already running; if not it will then put the car onto the reds (ON), then after a few seconds it will proceed to fire the starter motor. It will do this until either until a 10 second timer is up or it senses 12v from a random wire i found behind the dash that is only powered when the car is running, therefor it assumes the car is running and shuts off the starter motor.

The problem is this, my friends old non EFI hilux doesn't have a computer nor any other 12 source that i can find that is live only when the car's engine is running.

What possible ways would there be for my arduino to detect that the vehicle is running after cranking and thus turn off the starter motor? Would an option be to make a revolution sensor?


Try reading a spark plug wire with a Hall sensor. Or maybe engine vibration with a piezo disk.

I'll look into it! Hopefully i can find a solution that works within 1000ms or less, as starter motors arn't cheap ;)


Try the Tachometer, you know its running if the tach is at a certain rpm. That's what most off the shelf remote starters use.

Aussie_V8: What possible ways would there be for my arduino to detect that the vehicle is running after cranking and thus turn off the starter motor?

Running [u]during[/u] cranking is what you really need. The only reliable way I can see is to monitor engine RPM. If it's below about 300 rpm, the engine is cranking. Over 300 rpm (for longer than say a second) implies that it is running.

You could take a signal off the alternator. I think they get it off the exciter winding. This is, or was, standard practice for dual fuel vehicles and is used to change over to gas immediately after starting.

Spark timing is good and not all cars I've seen have a tach, but IMO tach data is best.

Did you ever publish a writeup on the mark one version?

Thanks guys for all the inputs! i guess the logical way to go would be to read the tach and make a decision based off of that. Wildbil, no i havn't as of yet.

The code for the project was mostly written by another member on this forum, as i'm quite new to the world of arduino i'm not that fluent with the language yet and had no idea how to create a state machine, but i will try and implement the tach sense completely myself..

Will update and do a project write up once it is completely finished :)