Chevy and GMC Duramax Diesel Forum banner

2018 3500 Door/tailgate locks unlocking and locking CONTINUOUSLY

6K views 11 replies 9 participants last post by  Blackmax65 
#1 ·
Pre-emptive strike:
-Yes I know it's under warranty and to take it to the dealer

This truck has just over 2k miles on it. Starting today, the locks lock and unlock rapidly and continuously on their own. This starts when the unlock button is hit either on the door itself or from the key. Hitting lock stops this action, but as you can imagine it's then a pain to get in or out of the truck & also sets off the alarm.

I work with this truck and can't afford to leave it at the dealer just yet, but also will be driven insane if I have to listen to these locks do this for the next few days, not to mention running the batteries down (it does this whether the truck is running or not).

I know in previous GM trucks with lock gremlins, the most likely culprit has been a problem with a body control module. I see there are several fuses for the BCM in this truck. Any info on which, if any, fuse(s) are dedicated to the part of the BCM that controls lock actuators specifically? I can get by with using the key to lock/unlock for a few days, but I couldn't find in the manual which fuse is for locks.

The batteries have been disconnected so the ECU can reset, but that did not help. Nor did removing/replacing batteries in the remotes.

Thanks in advance for ANY advice. I'm sure this will require some warranty work, but as I said I can't be without it just yet and the dealer doesn't have any 3500s to loan.
 
See less See more
#3 ·
Did anyone have any updates Or find what it took to solve this problem I’m having the exact same problem in my 2016 GMC 2500 Duramax Denali. I can’t seem to pinpoint it just yet. As I’m sure you all know this problem is extremely irritating lol.
 
#5 ·
Could be the BCM but could also be the drivers door control panel switch- pretty cheaply made and if any moisture gets in the system goes crazy. Had this exact thing with the '13 I had and just replaced the switch panel and fixed. Never had any more problems
 
#7 ·
If the RCDLR gets wet and it often does, from a leaking rear window or 3rd brake light, corrosion forms and causes such problems. Somewhat similar to Sambor's post.
 
#9 ·
Haven't had it happen on the truck yet, but had it happened on a previous car, and it turned out to be the computer ground wire, it couldn't hold memory because of the unstable connection. It drove me crazy.
 
#11 ·
Right after a huge storm.
Lightning plays hell with the electronics in our trucks. Lightning doesn't even have to actually strike the truck, no burn holes, etc to be seen. I sure hope that's not your problem, but if it is, you may need a new truck.
 
Top