remote start via disposable cell

No, sorry, I didn't read your blog at the time I posted (I was at work and anything with the word "hack" in it is blocked).

If you have 1.35vdc coming out of the phone all you need is a 2n3904 transistor from radioshack.  It wouldn't hurt to put a 220 ohm resistor in series with the base, ground the emitter (to both the phones ground and the cars ground) and then the collector will go straight to the relay coil with a diode across the coil.

You can use this diagram:

to take the status output from constant to a short pulse.  This could be hooked to the status output so as soon as the remote start activates it sends a short pulse to the "end" button, thus canceling the call.  You could then use the phone to shut the car back off!  You, of course, would have to reverse this diagram to work with your (-) status output - just put the cap and resistor on the postive side

I think finding a way to shut the car off will make it that much better - especially when showing it off to your friends.  It will be cool to see you call your car to start it, but if you have to walk to the car to shut it off you know your friends are going to ask why you can't call it and shut it off!

Definately a fun little project, and it seems like your phone has a lot of powerful little features on it.  It would be cool if you could somehow come up with a way to have it send you a text message when it starts.  :)

I just installed this item two days ago and LOVE IT!

It has a built in quad band  gsm phone with wired external antenna  you just put a prepaid sim in it. o2 wireless is the best because $10 airtime doesnt expire for 90 days and text messages are only 5 cents each. very good unit and programmable via usb cable with their software or by text messages. Only messages from programmed phone #s will be able to start your car etc. I looked all over for something like this and this is the only thing I found that came close. I only use one output to activate my remote start and it works great. The only drawback to this unit aside from the price is that it is shipped from Lithuania and takes about 4 weeks to arrive.

sorry my previous post I coudnt figure out the links.

Just do a search on ebay for

SMS Pager Home/House/Car/Boat/Moto

My alarm already has a feature that will start it at the same time everyday.  My wife and I use the car alternately, however.

Also meant to mention, my remote start will shut down automatically after running for 12 minutes.

I am on a CDMA network.  The GSM chip thing sounds like and option.  As far as price, if I get this to work, I will be paying the same for service, and it will cost me maybe $10 in parts.  Also, I would like to do it myself, just for the adventure.

If I get this to work, I will have the options to:  Start my car via call.  Start my car via SMS/Text.  Set up to 4 independent and recurring (if I choose) alarms to start my car.  Set schedules and calendar events to start my car.  Expand on this setup by adding shutdown capability, text back, twitter, whatever!

You guys all have some great suggestions, and the12volt has not disappointed me with it's wealth of help and breadth of knowledge.