HI, I have a 2007 Avalanch and we tried to put a viper alarm in the car with factory engine start. The shop worked on the car for a wile and determined they couldn't get the pass key bypassed for some reason. We bought bypass module that is for the 07 Avalanche but the car still turns off after a few seconds. Is there a way to hook the aftermarket alarm to the factory engine start?

Thanks

 

Have you tried to call tech at Viper? They may be a good source for troubleshooting since I am sure you are not the first Ava owner to install a viper system. Good luck

 

The stereo shop called viper and they said it was impossible. They also called local shops and module makers, all gave the same answer. They also tried to install the standard viper remote start and couldn't get that to work. They finally gave up and did the rest of the install for free, Just no remote start. So i took one of my remotes and soldered some wires to it and a few relays. Then i connected that to 2 of the channels of the viper. That did the trick.So the factory remote is now in a box in the car and activated by the viper alarm.Sort of a back wards way to do it but it works.

 

should be interesting when something screws upand warranty comes into question

 

Thats what I call McGuyvering a solution. Very creative.

 

here is solution info.
this should help
It was done on 07 Tahoe, but avalanche would be the same as far as doing alarm

 

The problem wasn't finding all the wires they needed for the engine start, they found all of them. The problem was getting the car to run more then a few seconds at a time. They tried every combination of modules and wires that viper had as well as everything the module company had and all failed to get the truck to stay running. The remote bit works perfect and cost almost nothing and then there is no VATS bypass in the car. Only other crazy thing they ran into was the power window roll up. Turns out GM makes 3 cars that have this type of window setup. The new 07 Avalanche is one of them. The windows rest open intead of ground or power. It took them a wile to get that figured out but its working fine except for the express up. The back windows have express down and up and the front only has express down. Maybe i'll take it back and see if they can figure it out.lol

 

May be they did not connect alarm to the correct TACH wire, or did not programmed tach correctly.