Multipro tailgate upper section lockout procedure - anyone used it successfully?

Another JR · November 3, 2022

I have a 2021 GMC 3500hd SLT. I read on line about the lockout procedure for the upper tailgate, and asked the dealer and they printed out the same procedure: With key fob within 3 feet of the tailgate buttons, press and hold the upper button for three seconds until the tail lights flash. The upper tailgate is locked out and won’t open if the button is pressed. Repeat procedure to restore normal operation.

Has anyone had success with this? When I try to do it the upper tailgate just immediately releases even though I’m holding the button. Am I missing something?

Thanks

NWStever · November 4, 2022

22 hours ago, Another JR said:

I have a 2021 GMC 3500hd SLT. I read on line about the lockout procedure for the upper tailgate, and asked the dealer and they printed out the same procedure: With key fob within 3 feet of the tailgate buttons, press and hold the upper button for three seconds until the tail lights flash. The upper tailgate is locked out and won’t open if the button is pressed. Repeat procedure to restore normal operation.

Has anyone had success with this? When I try to do it the upper tailgate just immediately releases even though I’m holding the button. Am I missing something?

Thanks

Yes I've successfully used the "3-second procedure" to disable the inner tailgate release. When disabled, the tailights will flash if a release is attempted. Maybe on your truck the microswitch behind the release button is corroded and is now acting like a momentary switch. This explanation may account for your observation of immediate release upon button push even though you haven't released the button.

Addendum: I checked operation on my truck and I found that pushing the upper button caused the inner gate to unlatch immediately even before button release. Given that, an alternative possible failure mechanism is that internal corrosion of your microswitch causes flaky, intermittant contact insufficient to hold for the required 3 seconds. Although one would hope, if not expect, that GM would spec an environmentally sealed switch to avoid such problems.

Edited November 4, 2022 by NWStever
add clarification

sheath · November 4, 2022

22 hours ago, Another JR said:

I have a 2021 GMC 3500hd SLT. I read on line about the lockout procedure for the upper tailgate, and asked the dealer and they printed out the same procedure: With key fob within 3 feet of the tailgate buttons, press and hold the upper button for three seconds until the tail lights flash. The upper tailgate is locked out and won’t open if the button is pressed. Repeat procedure to restore normal operation.

Has anyone had success with this? When I try to do it the upper tailgate just immediately releases even though I’m holding the button. Am I missing something?

Thanks

With the key fob in my pocket, I hold the upper tailgate button for about 3 seconds, and the tail lights flash. Has worked the 4 or so times I've done it.

Same procedure to unlock..

gemarsh · November 5, 2022

I think this lock out started in 22 my. I have a 21 1500. It will not work. Isn't in my owners manual.

I also have a 22 3500. Lock out feature works on it. Procedure is in the owners manual.

Another JR · November 5, 2022

14 hours ago, gemarsh said:

I think this lock out started in 22 my. I have a 21 1500. It will not work. Isn't in my owners manual.

I also have a 22 3500. Lock out feature works on it. Procedure is in the owners manual.

That makes sense. Sheath’s and NWStever’s trucks are 22s. It’s not in my owner’s manual. Is it in the manual for your 22 hd truck? (Edit - I now see gemarsh said it is in the 22 manual. Thanks.)

Edited November 5, 2022 by Another JR

sheath · November 5, 2022

Wonder if there is a software update the dealer could do for you to make it work?

Another JR · November 5, 2022

I can ask about a software update. However, everything is working well on the truck and I am reluctant to let the dealer mess with it. When I have expressed that general reluctance to the service advisor, he actually agreed.

Z45 · November 5, 2022

2022+ models this works, prior models NO.

sheath · November 7, 2022

On 11/5/2022 at 10:27 AM, Another JR said:

I can ask about a software update. However, everything is working well on the truck and I am reluctant to let the dealer mess with it. When I have expressed that general reluctance to the service advisor, he actually agreed.

Yeah, I can understand where you are coming from. I'm out in oil/ranch/farm land. Probably 90% of the local dealer's business is trucks, and upfitting. They know the product extremely well. Had them program the truck to eliminate the two idle shutdown programs (inside, and outside).

Not sure I'd have been as confident with an average city dealer.

Any chance there is a dealer within driving distance with that kind of truck experience? Might be worth the drive.

eta: Having that lock-out feature is very comforting. If I ever damaged the tailgate from my own stupidity, it would be a really bad day.

Edited November 7, 2022 by sheath

Another JR · November 7, 2022

I asked the dealer service advisor to find out if a software update can add this feature. I’ll post what I hear back.

H20ENG · January 16, 2023

My 22 has this feature and the instruction sticker inside the tailgate latch area. I use my inner gate a lot. I figured the ONE time I forgot to program it out would be when I had the hitch in and an instant $1000 mistake. I was going to DIY a switch but ended up getting the tailgatefix.com switch and hitch pin. It was very easy to install and works every time.