1999 denali alarm problem

I have a 1999 Yukon Denali that came with a Compustar 2 way starter/alarm. Everything works great with exception of the alarm goes off once the engine stops with either the 15 minutes time up or manually stopped by button 2. It appears the alarm is active and arms prior to the engine stopping. I have disabled the shock sensor via the remote, but that did not help.I am sure it is a remote setting, but can't find instructions to fix this. Please help. Pro P2W9000FMR remote. Thanks.

Does the remote show what zone is being triggered?

No it doesn't. I have experimented and if I manually disarm/unlock the doors prior to the time running out or remotely stopping the engine, the alarm does not sound. This obviously isnt any good because if the timer runs out, the alarm is triggered.

When you say the alarm triggers, is the horn sounding or siren?

Both the horn and the siren go crazy. It seems that the alarm sensors are armed at the instant the truck shuts off without any delay and therefore the horn and siren both alarm. Like I say the only way I can counter this is if I unlock/disarm the locks/alarm prior to the engine stopping. I would think for it to work correctly it should rearm the security with a delay after the truck is off and all vibrations stop.

if the horn honks then its most likely you have a factory alarm, done of couple of these within that 99 year and have to turn the key at the switch to disable it , its not like the normal disarm from the drivers door., theres two ways to disarm it  one way is using a relay and mimicking the key and the other is doing programming on the factory alarm

sounds like the factory alarm is causing the compustar to go off. you need to check that oem alarm is being disarmed before start.

When I bought the truck last week all was fine and worked well. I did make a change to the delayed headlamp exit illumination and have since changed it back. I thought that might have been the problem. Didnt change anything. The alarm zone on the remote is the DOOR. I cannot silence the alarm even after starting the vehicle with the key? Need to get a pro on this I guess, although I thought it was only a setting that I may have messed up. Any other ideas? Thanks.

check to see if the doors unlock after turning off the car by remote. take note to see if the interior lights turn on or not. i'm wondering if you truck turns on the interior lights when the engine is turned off.

The doors do not unlock after stopping. The locks do not lock while starting either. Appears the only time the locks activate is when pushing button 1. The interior lights turn on and stay on after the engine stops, as well as the radio remains on. Looks like the lights turn off about 30 seconds after the engine. once the engine is off, the headlights flash twice prior to the alarm/siren going. ???