2004 cavalier - RS - by pass alarm?

Hello, Today I put an astro QS1 (one button, no locks) into a 2004 chevrolet cavalier. Went smoothly up until I armed up the factory security, then the alarm would sound and the "security" and "service engine" lights would come on. The lights don't appear when started with the key. directechs and another site say the alarm should disarm when passlock II and ignition is present. Nope. Astro's chart gave a diagram with a relay and 2 diodes to feed the pink Acc + when "ground when running" is present. Nope again. Anyone gotten around this? Like I said, it will start and run but the check lights come on and alarm sounds. Thanks much,

Quick addition: I'm using a passlock II bypass that connects to the purple diagnostic wire under dash. I've used about a dozen of these slick 4 wire setups in the past w/ no probs.

The passlock bypass does not interface w/ the purple wire @ diagnostic plug. Sounds like you have a data bus interface, which is not required for this car. You need a DEI 55L or 555T. The factory alarm is arm/disarm from factory remote only; ideally you need a unit w/ keyless entry and/or alarm. What is happening by using the factory keyless is that the remote start has no way to disarm the factory alarm, thus causing problems w/ the remote start, not to mention the Passlock is not interfaced properly.Chris

Store Manager

wiremadness wrote: The passlock bypass does not interface w/ the purple wire @ diagnostic plug. Sounds like you have a data bus interface, which is not required for this car. You need a DEI 55L or 555T. The factory alarm is arm/disarm from factory remote only; ideally you need a unit w/ keyless entry and/or alarm. What is happening by using the factory keyless is that the remote start has no way to disarm the factory alarm, thus causing problems w/ the remote start, not to mention the Passlock is not interfaced properly.

The interface I'm using is an OM-Passlock-4 by Astroflex. It's meant for 98+ GMs and has settings specifically for cavaliers w/ and w/o factory security. So it should have worked...

Thanks for verifying that the factory alarm can be controlled through the remotes only. I'm going to suggest that they get a QS4 that can do locks and then try to bypass via the old normal r-code style.

if you read carefully the data module do not shut down the factory alarm on the cavalier/Sunfires.... you have to use a 555L instead.... i use the GMBP data/Passlock modules here as well and they say right on them not compatible with the J body vehicles IF they have factory alarm.....Kevin Gerry

Certified Electronics Technician

MECP First Class Installer

Owner/Installer

Classic Car Audio

since 1979

Kileil....,The only way to ARM the factory security is with the factory remote. To override it is with the  second ign. wire setup, and diodes that astroflex told you about. Do you have the diagram too? If you never carry the factory remote and USE it ....you don't have anything to worry about!

There is a module called GMDACAV that does everything. It is only designed for Cavaliers and Sunfires that have factory keyless entry/alarm. It does the Passlock II and arms and disarms the alarm. Just mount it a foot away from the BCM and they work great. You need to use the disarm function of the remote start to unlock the doors and disarm the alarm first prior to starting. Have the remote starter relock the doors after start up.   It will even do the trunk release.sparky