anyone know how much this is going to cost me, boot keeps opening when I unlock doors , tried replacing the fob, replacing the exterior handle , seems it's down to either frayed wiring or a break in the line 

 

fml

it could also be a failing boot latch, I have seen this exact thing happen on fiestas and as the focus and fiesta do have common parts architecture it is possible the latch is failing.

Hi Sucof Drof. I have the  same fault and after a week of looking through forums you are the only other person with the specific fault of boot popping open when I unlock the car. This started happening last week, after a software update to update the maps in the satnav. Every time I unlock the car I have to walk round and close the boot before I get in. Sometimetimes it does it when I double lock too.

I put a terminal block in at the boot latch to measure stuff and the yellow/violet wire sits low ( 0v ) until you press unlock, press the boot latch button above the number plate or press the boot button on the fob. It then gets a momentary high ( 12v) which opens the boot. After reading all the forums I suspected a wiring fault. I diconnected the loom at the connector above the rear fuse box behind the trim (big black plug) When you unlock the car the lights flash. A short from the lights flashing could maybe open the boot. Testing the loom showed no breaks or shorts with other wires between the yel/vlt wire at the latch and at the big black connector. Moving over to the 'live' side of the connector, the yel/vlt wire is still sitting low and going high momentarily when any unlock is operated. THE WIRING IN THE BOOT IS APPARENTLY OK. I then pulled fuse F65 out! According to the diagrams, pulling this fuse should stop power getting to the relay suppling the solenoid in the boot latch. Nothing should open it! What this did do was stop all the designed behavior i.e. the switch above number plate and boot button on fob stopped working BUT every way of unlocking the car still pops the boot open! This wire is supposed to go from the relay in the BCM to the latch solenoid and nowhere  else. This leaves me thinking of a couple of possibilities. A short between the big black connector in the LHS of the boot and the relay output at the BCM, (apparently on pin 12 of the BCM connector C2280E) or a fault with the BCM. So I'm about to go out and cut the yel/vlt wire coming out of C2280E and see what I can figure out. I'll be watching this forum for your progress but I'm beginning to suspect pin 12 on  C280E, which is the boot latch relay output, is also being supplied by one of the 'door unlock' relays in the BCM.

4 hours ago, birdman2015 said:

I then pulled fuse F65 out! According to the diagrams, pulling this fuse should stop power getting to the relay

Do you want the full Ford schematics for your car, or do you already have them ?

thanks for that birdman, I'm hopeless with stuff like this, I've the car booked in with ford on Tuesday so I'll update this when I know more 

4 hours ago, unofix said:

Do you want the full Ford schematics for your car, or do you already have them ?

I have the Haynes manual plus a few diagrams of the C2280E connector, unofix. The full Ford schematics would be very handy to have. I've only had the car a month and I'm sure it would be a great reference.

I'm dying to see what ford make of the fault, Sucof drof. I fitted 'License Plate Light Micro-switch Button Rear For Ford Focus M3' and ordered Ford Focus Tailgate Wiring Loom Harness F1ET-17N400-BBH ESTATE 2015 - 2018 MK3. The VIN for the car the loom came from is identical to mine apart for the last number. Probably made on the same day!

I also ordered 'Universal Car Rear Lid Tailgate Electric Trunk Release Switch'for my backup plan if it is the BCM.

59 minutes ago, birdman2015 said:

The full Ford schematics would be very handy to have.

Ford Focus 2018:

https://drive.google.com/file/d/1F05Vqyik2i0p2WdUCxFaK4kQNVCJQHq3/view?usp=sharing

H Unofix.Thanks for your help. I should have been more forthcoming. Although it's an '18 plate I think the car is a MK3. Sorry about that!

Ford Focus 2014 onward

https://drive.google.com/file/d/1-GuVIWeFP7_8Dk_FYYQbyLCIDzHgggZ6/view?usp=drive_link

Thanks Unofix. That'll save a lot of time having it all to hand!

me again lol 

 

do you think ford will diagnose the problem with the diagnostics tool or will it be a more manual inspection, only reason I'm asking is I'll need to get hire car for duration

58 minutes ago, Sucof drof said:

do you think ford will diagnose the problem with the diagnostics tool or will it be a more manual inspection,

More of a test and trace procedure. I expect they will drag it out for half a day @ £120 per hour.

10 minutes ago, unofix said:

More of a test and trace procedure. I expect they will drag it out for half a day @ £120 per hour.

they quoted me 120 for the rest, I suppose that's the Chinese dinner out the window next weekend lol

28 minutes ago, Sucof drof said:

they quoted me 120 for the rest, I suppose that's the Chinese dinner out the window next weekend lol

Crikey, my beef curry & rice is only £8, what kind of Chinese do you have?? 🤣

ford just rang me back, traced the wiring back To a loose connection (had actually separated ) in the roof headliner all sorted for 340 euros, Chinese dinner is back on 

1 hour ago, Sucof drof said:

ford just rang me back, traced the wiring back To a loose connection (had actually separated ) in the roof headliner all sorted for 340 euros, Chinese dinner is back on 

Thought that was steep till I realised that you're in Co. Clare! Just as well the average salary there is considerably bigger than the UK, enjoy your Chinese 🤣

@birdman2015 just updated , I see you more savvy than me so you might be able to sort yourself 

Glad you got it sorted. I'll need to check the wiring in the headliner. I posted my 'fix' under 'boot pops open on unlock'. It solves the immediate problem of walking round to close the boot all the time but the boot button on the fob doesn't work. My fix involved many really uncomfortable hours in various unlikely positions out in the freezing cold. A twenty stone old man on his back hanging out the passenger door with his head in the footwell and arms where the glovebox should be is not savvy. Waiting on a phone call, wondering what to get from the chinese sounds much better.