Drivers door boot release not working

[JustmeJB]

I have a 2017 e class estate and the drivers door boot release button doesn't release the boot. I've tried with engine on and off (at standstill obviously) and also with the engine switched off (but with the ignition still on) and no joy. The weird bit is that the key doesn't work when I'm sat in the car either but the key does work when I am out of the car whether the car is locked or not.

Anyone have an idea of where I need to look?

 

[BTB 500]

Just to double check ... you are holding the tailgate release switch, rather than just clicking it momentarily (that's the way it works on our C Class, anyway)?

 

[JustmeJB]

Just to double check ... you are holding the tailgate release switch, rather than just clicking it momentarily (that's the way it works on our C Class, anyway)?

Yes, I'm holding it for quite a few seconds. I previously had a 2014 e class coupe and that worked no worries but as you say it did take a second or so to activate. Guessing this is a fail safe in case you catch it by mistake.

 

[Shadgrind]

Are we talking about the boot switch on the actual boot or the remote inside the car? If it’s inside the car does the little light go red when it is open?

Have you tried the fob to open it, I would assume you have.
1. Try opening from the tailgate itself
2. Try the fob
3. Try the release inside the car

Delete the above as applicable and report you findings…

In the mean time try YouTube, that helps me a loto

 

[JustmeJB]

Are we talking about the boot switch on the actual boot or the remote inside the car? If it’s inside the car does the little light go red when it is open?

Have you tried the fob to open it, I would assume you have.
1. Try opening from the tailgate itself
2. Try the fob
3. Try the release inside the car

Delete the above as applicable and report you findings…

In the mean time try YouTube, that helps me a loto

Yep the remote switch on the lower front of the drivers door.
The switch on the tailgate works fine.
The key fob works fine if I am outside the car regardless of whether it's locked or not the boot still opens when the key fob button is pressed.
The release inside the card doesn't work regardless of whether the car is running, switched off or fully off. Strangely the key fob doesn't work from inside the car either.

I had a look on youtube and there were some vids mentioning the wiring near the hinges and also others mentioning a setting both of which I have checked and they're not the issue. The wiring near the hinge results in all modes of opening u/s and the setting isn't on my car anyway.

 

[Shadgrind]

i would start at the switch, spray switch cleaner on it while pushed down, if you dont have that temporarily use wd40,then get some switch cleaner to clean up the WD. Failing that, you need to get to the back of the switch, check for broken wires, check for power, with a meter or tester. There should be three wires a switched live a ground wire and a constant live. The first one to find is constant live, find a known ground , a bare metal bolt he’d in the door hinge will do.
With the meter in voltage mode, 20v scale usually works, then with the black lead connect to ground. Try touching each of the wires until you get 12v. This is your constant live, check the other two wire with the switch pressed, one of them should then give you 12v. Meaning the last wire is ground, Then check for continuity in diode mode (so the meter beeps when it sees a circuit.
No live wire broken, you have live but pushing button doesn’t give you 12v, switch broken, no ground ground wire broken.

 

[JustmeJB]

Cheers Shad, I'll give that a go and see what I find.

 

[JustmeJB]

Well the plot thickens. I sprayed some contact cleaner across the switch and noticed it was sticking in both the open and close positions. I then noticed if I opened the boot using the keyfob I could stop it mid flow with by pressing the drivers door button so it definitely has power to it (as a note I tried to remove the switch but couldn't manage it without thinking I was going to snap something). I then sprayed more cleaner and moved the switch back and forth and it then opened the boot. For a while I could open, stop and close the boot after a few back and forth movements. However now the switch has gone quite loose so I suspect it's knackered. Going to call the dealer and see what price a new one is.