Disarm Security without Key Fob

gw1500se · April 20, 2017

I have a 2000 GMC 1500 Sierra. Recently when I tried to use the key fob to disarm the security system I found the fob battery had died. Fortunately it was in a Walmart parking lot so I was able to replace the battery immediately. However, suppose I was in the middle of nowhere and the key fob failed for whatever reason. How do I disarm the system with just the key? TIA.

newdude · April 20, 2017

Unlock the door with the key and then turn the key to the ON position in the ignition.

Coby7 · April 20, 2017

That will stop the horn from blowing but will not disarm the alarm if it was set by the FOB. Some years you just had to turn the key to unlock twice but not sure this pertains to the 2000 or not depending if it's a classic or new body style. You can try it and see if the lock Icon stops flashing when you turn the key twice.

gw1500se · April 20, 2017

Thanks for the replies. Perhaps this is not the same type of security system you are expecting. There is no icon or horn blaring just a sort of clicking in the dash until the disarm button is pressed on the fob. Only then will the ignition be enabled. Turning the ignition key on and off 2 or more times seems to do nothing.

Coby7 · April 20, 2017

Just means it was set like that by you or a previous owner. The manual states that it comes preset from the factory to blare horn and flash headlamps, but you can change this to different settings. You should still have a flashing LED in the center console when alarm is armed. And when I said turn key twice I meant in the driver's door not ignition. If your FOB is a GM#15732803 the the only way to disarm is with the FOB if it was armed with the FOB.

newdude · April 20, 2017

Thanks for the replies. Perhaps this is not the same type of security system you are expecting. There is no icon or horn blaring just a sort of clicking in the dash until the disarm button is pressed on the fob. Only then will the ignition be enabled. Turning the ignition key on and off 2 or more times seems to do nothing.

Is it an aftermarket alarm system perhaps? Does the remote look like a GM one?

gw1500se · April 21, 2017

The truck was bought used so I don't know what its owner did previously. It took me a while to figure out that I needed to disarm on the fob to start the darn thing (it automatically arms). I'll have to try the double door unlock tomorrow. I think this is a standard GM system but I was not aware I could program it. I'll have to research that.

gw1500se · April 21, 2017

The double key turn in the door lock worked. Thanks for that. I just have to remember not to use the fob to arm it and let it auto arm. I still need to research the programming part but I now have what I need to know in a pinch.

Coby7 · April 22, 2017

The picture you show is of an aftermarket alarm system not GM. Unless your truck has a trunk lol

newdude · April 22, 2017

The truck was bought used so I don't know what its owner did previously. It took me a while to figure out that I needed to disarm on the fob to start the darn thing (it automatically arms). I'll have to try the double door unlock tomorrow. I think this is a standard GM system but I was not aware I could program it. I'll have to research that.

Scan-170420-0001.jpg

If it was just the factory theft then the key method I mentioned would work. Being an aftermarket system, whole different ballpark. I would try Code Alarm's website maybe?

gw1500se · April 22, 2017

The picture you show is of an aftermarket alarm system not GM. Unless your truck has a trunk lol

Dunno. It has a GM logo (not GMC) on the other side. I assume the fob is labeled that way because it is also used for other GM vehicles. Anyway, as I said, I'm good.