add alarm to 2012 impala lt

The alarm will trigger when the car starts. Don't try to reinvent the wheel. Get a combo unit and be done.sparky

I'm planning to use a combo unit and use the aftermarket remote fob to control it... the only thing I'm going to do differently on the install is wire the start function to activate an oem keyfob instead of directly powering the car circuits. The alarm should expect the car to start since it will be sending the request out. I'm looking at this as an experiment, more for fun at this point than expecting it to work. If it doesn't work out I can always rewire the remote start functions to the car like a normal install.

I guess you have a lot of time to waste. It won't work right. You asked for experienced advice and got it. Do what you want. sparky

At which time our OP might find it easier, less time wasting and cheaper to add an R/S with security.

Thanks Howie.sparky

sparkie wrote: The alarm will trigger when the car starts.

Sparkie is correct. Listen to him.

tdf1974 wrote: The alarm should expect the car to start since it will be sending the request out.

That's not the way it works. When the alarm is armed, if it 'sees' the ignition become live it will be triggered. On a DEI alarm, this is a Zone 5 trigger. R/S systems have an IGN out wire TO the alarm. When the R/S activates, this wire remains dead, so an armed alarm isn't triggered by IGN becoming live.

Thank you for giving a valid reason and area I may run into an Issue. The thing is the factory RS does not utilize the typical ignition circuits.   Everything on this car is canbus, nothing is directly controlled, turning the key only sends the PCM a signal to engage the starter, turning the key m

Stupid phone. As I was saying a factory rs does everything through the module network, the ignition key circuits never change state. It's all a mute point, I've decided to wait it out a while and see if the aftermarket offers a more seamless integration to the factory remote start. GM has now made remote start standard on most models, which means more people will wish to add alarms to these vehicles.

All of the leading alarm R/S manufacturers offer seamless integration via the vehicle data networks so your last comment is wrong.

My original question was regarding which interface would work best with oem remotes, all I got was "install a full featured alarm with remote start". ok. given the fact I'm now ok with not using the oem remotes are you saying an interface will initiate a remote start via factory protocol, and include all the amenities of a factory remote start? That's all I'm after at this point.