Tailgate lock

[Left Coast Geek]

a week or two ago, my tailgate no longer auto unlocks if I have the dongle on me. I can manually unlock it with the dongle, or by touching a side door handle to unlock the car, but the buttons to open the tailgate as well as the tailgate window do nothing if the vehicle is locked. I've been all through the advanced settings on the dashboard menu, and I don't think i've seen anything that would affect this.

any clues here?

 

[apex96]

Chances are your vehicle battery is slowly failing. Loss of touch sensors on the doors and perimeter unlocking functions are usually the first subtle signs that you may need to replace the battery soon.

Easy way to check is to leave it on a trickle charger overnight and see if your rear lift gate and hatch work the next morning. If it works after being on a trickle charge overnight, you know it is battery related.

 

[TheDoug]

Chances are your vehicle battery is slowly failing. Loss of touch sensors on the doors and perimeter unlocking functions are usually the first subtle signs that you may need to replace the battery soon.

Easy way to check is to leave it on a trickle charger overnight and see if your rear lift gate and hatch work the next morning. If it works after being on a trickle charge overnight, you know it is battery related.

This is where I would start as well. When my battery was weak strange things stopped working properly.

 

[Left Coast Geek]

huh, last drove it a few miles last night. at noon today, its 55F, the low was 40F, unlock and open drivers door and pop the hood, my FLuke says 11.96V, Bingo, we have a winner Appears to be original FoMoCo battery, although it *looks* totally new.

Huh, Ford is using H7 AGM now, same as my wife's Mercedes.

 

[Left Coast Geek]

hmmm. battery store ran a test on the battery using a carbon pile 100A tester, said the battery has about 750 CCA left out of its original 800, and as far as they can tell, its fine, but its voltage was a little low. I started the engine, they saw 14.x V at the batt so it seems like the alternator is working. they suggested hooking up a charger, so hooked up my NOCO Genius 10 in AGM mode.... charger declared battery full after a hour or so... I've found my cigar plug volt meter so I can watch the batttery while driving to see whats going on.

 

[Woodwolf]

I notice you attached the negative charging lead directly to the negative battery terminal. I am let to believe the correct way is to attach this lead to the bracket of the battery status monitor (the black component in front of terminal) This way the system update’s itself to the new charging level. YouTube has more info , check it out , think it’s Makuloco

 

[Left Coast Geek]

Yeah, I realized that looking at the picture.

Anyways, was scared seeing 11.9 or less volts the morning after a full charge so I put a new battery Tuesday. ... I stumbled around trying to figure out how to do the battery reset, and found a page in the owners manual saying that sitting off for at least 8 hours will cause the BMS to learn the new battery, no fancy reset required.

Tailgate proximity unlock still not working. Remote will open the tailgate or unlock. Proximity and any side door handle will unlock,then you can open the tailgate.

 

[Left Coast Geek]

Chances are your vehicle battery is slowly failing. Loss of touch sensors on the doors and perimeter unlocking functions are usually the first subtle signs that you may need to replace the battery soon.

Easy way to check is to leave it on a trickle charger overnight and see if your rear lift gate and hatch work the next morning. If it works after being on a trickle charge overnight, you know it is battery related.

well, the overnight charge didn't help, and neither did a brand new fresh 800CCA AGM battery.

so now what? I have to use the fob to unlock the doors or open the tailgate, I can't just walk up and push the button on the tailgate to open it if its locked.

 

[apex96]

well, the overnight charge didn't help, and neither did a brand new fresh 800CCA AGM battery.

so now what? I have to use the fob to unlock the doors or open the tailgate, I can't just walk up and push the button on the tailgate to open it if its locked.

Did you reset the bms system after having the new battery installed?

If you’ve reset the bms to account for a new battery, I might start by checking the modules in forscan. There may be a soft code stored that indicates that a module isn’t properly transmitting.

Checking and swapping batteries was the simple route and most logical option knowing the issues low voltage can cause. If you’ve ruled out the battery, checking module communications would be my next step.

 

[99WhiteC5Coupe]

a week or two ago, my tailgate no longer auto unlocks if I have the dongle on me. I can manually unlock it with the dongle, or by touching a side door handle to unlock the car, but the buttons to open the tailgate as well as the tailgate window do nothing if the vehicle is locked. I've been all through the advanced settings on the dashboard menu, and I don't think i've seen anything that would affect this.

any clues here?

Since the two buttons that do not recognize the remote fob are mounted on the tailgate, I’d suspect a wiring issue - perhaps in the conduit between the hatch door and the body?

Has the rear hatch inner trim panel ever been removed? Any vehicle damage to the hatch?