Alarm keeps going off when I use key

[Tamcphail89]

Just picked up an 02 Yukon Denali. Key fob doesn't work, gotta get a new one. But when I lock the doors from the inside and get out, then unlock with the key it sets the alarm off.

Anyone have an idea why and how to disable that?

Thank you guys

 

[Cbncanada]

I think you will find the alarm is set when the doors are locked either manually or by the fob. The vehicle can sense when the door is then unlocked with the key or the fob. The problem is most likely in the either the door module or the body control module. If the interior lights come on when the door is opened then the door module is probably ok. Can't say for sure but it is a good place to start.

 

[DougAMiller]

Could be the switch in the latch mechanism also. There are switches built into the latch that tell the computer that the door is open/closed and locked/unlocked. The contacts on these switches get dirty over the years and start to not make good electrical connection. So things like interior lights, Retained Accessory Power, etc start to not work properly. The quick solution is to replace the latch mechanism, the cheap solution is to remove the latch, disassemble and clean the contacts. There's a thread on this forum on how to do that.

https://www.tahoeyukonforum.com/threads/radio-and-interior-lights-wont-turn-off.91718/#post-1094050