Alarm goes off seemingly at random

[Sweet Pete]

My 2012 suburban LTZ's alarm goes off at random. Its been happening for more than a few weeks now. It seemed at first to do it only in the middle of the night, however Ive noticed it now doing it in the middle of the day. Despite my neighbors daughter's boyfriend's loud exhaust setting off my alarm, Im fairly confident the "random" alarm isn't from an animal or the sort so Im assuming its an electrical issue with the alarm system. I just bought the truck this winter and am assuming its the factory alarm. The battery is dated 9/18 and I haven't noticed any other electrical symptoms. I just put a meter on the terminals and they're reading +12v, terminal connections seem fine.

I (and Im sure some of my neighbors) would appreciate any help.

 

[swathdiver]

My 2012 suburban LTZ's alarm goes off at random. Its been happening for more than a few weeks now. It seemed at first to do it only in the middle of the night, however Ive noticed it now doing it in the middle of the day. Despite my neighbors daughter's boyfriend's loud exhaust setting off my alarm, Im fairly confident the "random" alarm isn't from an animal or the sort so Im assuming its an electrical issue with the alarm system. I just bought the truck this winter and am assuming its the factory alarm. The battery is dated 9/18 and I haven't noticed any other electrical symptoms. I just put a meter on the terminals and they're reading +12v, terminal connections seem fine.

I (and Im sure some of my neighbors) would appreciate any help.

The OE system doesn't do this unless there's a bad sensor on the hatch, hood or doors. The alarm would not go off unless someone opened a door normally.

GM sold as accessories, shock (17800431) and tilt sensors (17800432). You may have these, and if so, one or both would be under your dash on the driver's side. If you have the shock sensor, which is what would be causing the false alarms, it should be tie strapped to a wire bundle under your dash. There's a white knob which allows you to alter its sensitivity.

 

[Danny3737]

It’s very possible you may have a door switch that is just starting to go bad. A neighbor of mine had the exact same thing happen, but his was an earlier year. His would go off as soon as the temperature got around 30 degrees which was usually in the middle of the night. Yes, we were all happy once he figured it out.

 

[Sweet Pete]

Thinking out loud & in no particular order:
When the neighbors kids boyfriend drives by and my work truck with a Viper alarm is parked out front the trucks alarm gives me a warning chirp vs the suburbans fully alarm going off for 30 seconds. Does the GM OE alarm have a warning chip? The “random” alarm is also the 30sec alarm.

I don’t think air temp is a factor. The random alarm happens during the day now too and we are easily in upper 60s low 70s.

Assuming this is a sensitivity issue shouldn’t I be able to trigger the alarm by “shaking” the truck (eg push on bumpers, jump on running boards, etc)?

I looked for the shock and tilt sensors and couldn’t locate anything that looked like anything..., but what is this? It’s screwed just under the dash driver side. The blinky green light is visible to the driver. I never noticed it before. Maybe my alarm isn’t OE?

Based on your all’s feedback the alarm issue is either too sensitive or a bad door/ latch sensor. Assuming it’s not the sensitivity or I can figure how to rule that out, how would I determine which door sensor may be going bad?

 

[swathdiver]

View attachment 244149 Thinking out loud & in no particular order:
When the neighbors kids boyfriend drives by and my work truck with a Viper alarm is parked out front the trucks alarm gives me a warning chirp vs the suburbans fully alarm going off for 30 seconds. Does the GM OE alarm have a warning chip? The “random” alarm is also the 30sec alarm.

I don’t think air temp is a factor. The random alarm happens during the day now too and we are easily in upper 60s low 70s.

Assuming this is a sensitivity issue shouldn’t I be able to trigger the alarm by “shaking” the truck (eg push on bumpers, jump on running boards, etc)?

I looked for the shock and tilt sensors and couldn’t locate anything that looked like anything..., but what is this? It’s screwed just under the dash driver side. The blinky green light is visible to the driver. I never noticed it before. Maybe my alarm isn’t OE?

Based on your all’s feedback the alarm issue is either too sensitive or a bad door/ latch sensor. Assuming it’s not the sensitivity or I can figure how to rule that out, how would I determine which door sensor may be going bad?

The OE alarm does not have a "warn away" chirp but either accessory adds that function. If you have a Tech-2 or know someone who does, go into the BCM module, then the other body control module and then the Theft module. Scroll down and it will tell you what part of the vehicle initiated the alarm.

That thing is not OE or a GM Accessory. Trace the wires back and see if they go into 3 different plugs (LT Blue, Pink, Gray) into the BCM and one to the IP Body Relay Block. That would be your clue that this is an aftermarket alarm integrated into your computer system.

 

[Sweet Pete]

I traced the wires back...it’s a bit of a mess to me. That device has a purple and solid brown that seem to hit a relay with a bunch of excess wire taped then I’m not sure where. I added a few photos as have no idea what I’m looking at (first GM vehicle I’ve ever owned). Looks like there’s definitely some aftermarket stuff spliced in and whatever is going on with the OBDII pug is also confusing to me.

Could you please recommend a Tech-2? I quickly get overwhelmed and confused at all the options out there when I look online. Thanks.

 

[PG01]

Aftermarket alarm and thats a t for the obd port..... almost like a used cardealer uses to cut vehicles power if payment not made....