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I bought a 2015 LR4 a couple of years ago and have loved it. It has 113k miles and is in great condition. However, as of late I’ve been getting a “tailgate open” error on the dash, even when it’s securely shut.
it would only be annoying if it weren’t for the fact that once it thinks the tailgate is open, all the interior lights come on and if the vehicle is locked, it sets off the alarm.
Initially it was happening maybe one a month, but it’s now happening constantly. It’s draining my battery and sometimes I can’t even lock it, so it’s time to fix it.
someone on another forum suggested a faulty pin switch in the upper gate, but I only see a hook on the upper gate to engage the lower latch, so not sure where to go from here.
I’m hoping someone here can provide some additional direction or thoughts on where I should start.
This is for the D3 but it should be the same for the D4.
The tailgate switch can have water ingress (common) and short circuit.
When you press the rubbery part there is an aluminum plate behind it which then depresses a micro switch at the “bottom” of the switch module. When power is on (vehicle unlocked) the switch is fed 12 V current and an earth on the other wire. if your voltage is less you might have issues with the wiring. The circuit is then completed when the micro switch is depressed. The CJB monitors this through a FET and when circuit is completed the CJB side will trigger 12 V towards the actuator which then opens the lock which is, as you noted correctly, in the lower tailgate. Note that there isn’t a fuse.
Replacing the switch module is not terribly difficult. You can fiddle it out without having to remove the surroundings. In my case this wasn’t possible so the picture below show stuff removed. If the cable is bad you’ll have to remove the inside of the tailgate but again it’s a 15-30 minute job to get to it. Aftermarket switches are fine. In Europe you can get a FoMoCo switch if you really want “OE”. There might be issues that the connectors aren’t correct. They weren’t on mine so it involved some creative cabling and reusing the old connector and identifying which wire did what.
You might also have fault codes related to the tailgate.
This is for the D3 but it should be the same for the D4.
The tailgate switch can have water ingress (common) and short circuit.
When you press the rubbery part there is an aluminum plate behind it which then depresses a micro switch at the “bottom” of the switch module. When power is on (vehicle unlocked) the switch is fed 12 V current and an earth on the other wire. if your voltage is less you might have issues with the wiring. The circuit is then completed when the micro switch is depressed. The CJB monitors this through a FET and when circuit is completed the CJB side will trigger 12 V towards the actuator which then opens the lock which is, as you noted correctly, in the lower tailgate. Note that there isn’t a fuse.
Replacing the switch module is not terribly difficult. You can fiddle it out without having to remove the surroundings. In my case this wasn’t possible so the picture below show stuff removed. If the cable is bad you’ll have to remove the inside of the tailgate but again it’s a 15-30 minute job to get to it. Aftermarket switches are fine. In Europe you can get a FoMoCo switch if you really want “OE”. There might be issues that the connectors aren’t correct. They weren’t on mine so it involved some creative cabling and reusing the old connector and identifying which wire did what.
You might also have fault codes related to the tailgate.
False tailgate open error
