[bmw_solid]

Hi All,

Been doing some research and apparently it is possible to retrofit a boot release switch (right above the OBD port) and its a very easy low cost retrofit, as 3 wires need connecting, 1 for +ve, 1 for the locking access unit and one for the lighting unit (to illuminate the switch), as per post 15 in this thread:

https://www.e90post.com/forums/showthread.php?t=504404

Can anybody provide a wiring diagram or instructions on how to wire this up please?

I can find a switch for £15 on eBay but not sure about the wiring loom part number to connect the switch.

I can do with this retrofit as there is no way to release the boot - the key button does not work when in the slot and engine is ON. The unlock button only unlocks the boot, it doesn't release it.

Thanks a lot.

[bmw_solid]

Anyone?

[Lukec335d]

I would definitely be interested in this also. My boot only opens via the key at the minute...

[colorado.e9x]

You're telling me BMW deleted the boot release switch? Ridiculous lol

[bmw_solid]

https://f30.bimmerpost.com/forums/sh....php?t=1132318

I found the above thread but its for the F30, just wondering whether the diagrams in post number 8 could be useful, assuming it is a similar set up in the E9x models.

AND,

I have found another thread below... This person was/is selling the complete kit including the switch and wiring loom etc for £35. Not sure if this person is still selling it but I will try to contact this person and will update on here.

https://forums.m3cutters.co.uk/threa...t-kits.129728/

[MadJoe]

Originally Posted by colorado.e9x

You're telling me BMW deleted the boot release switch? Ridiculous lol

The trunk switch in the glovebox of pre-LCIs wasn't to open the trunk, but to to disable the trunk pop switch next to the driver's footwell, and the handle switch on the trunk itself even if the doors are unlocked. I believe it may also disable the key fob button, but I haven't used the switch in my 2006 in so long I've forgotten exactly how it works. I was told it was for valet parking so you could lock the valet out of your trunk if you wanted to (turn off the switch, lock your glove box, give valet the valet key).

[colorado.e9x]

Originally Posted by MadJoe

The trunk switch in the glovebox of pre-LCIs wasn't to open the trunk, but to to disable the trunk pop switch next to the driver's footwell, and the handle switch on the trunk itself even if the doors are unlocked. I believe it may also disable the key fob button, but I haven't used the switch in my 2006 in so long I've forgotten exactly how it works. I was told it was for valet parking so you could lock the valet out of your trunk if you wanted to (turn off the switch, lock your glove box, give valet the valet key).

I thought we were talking about the button that opens the trunk above the obd2 port

But yeah the trunk lock is for valet, I use it when I have to take my car to a shop

[bmw_solid]

Originally Posted by Lukec335d

I would definitely be interested in this also. My boot only opens via the key at the minute...

I contacted the chap on the M3 Cutters forum (username 'ccfj1') and he has said he is able to make the complete kit including the switch, wiring and harness/connectors all assembled for £40 for the E9x models.

This kit works both with and without the key in the car, engine on/off... Its £40 but worth while IMO given there is not much information on how to wire it up and the fact that a custom harness/connectors are also needed.

I have agreed to the price and will update you all once received and installed.

Hope this helps.

[bmw_solid]

I've received the kit and its pretty straight forward but not a kit I could make my self as I would have needed to source a customer harness for the switch, and a custom pin for the wire to connect to the CAS connector.

Connection is simply the following:

The harness connector (which goes into the switch) has 3 wires coming out:

One wire is for the ground
One wire is for the backlight/illumination for the button when lights are switched on

^^ These two wires can basically be connected using scotch locks or doing a bit of soldering

The last wire, as mentioned at the start, is the one which goes into slot 39 of the CAS. This wire has the correct pin crimped on it, as part of the kit by 'ccfj' on M3 Cutters forum. The pin basically needs to be pushed into slot 39 of the CAS harness.

Its has simple a that. Although, I would personally remove the battery before taking the CAS harness off as the CAS is a critical ECU of the car...

[Nickdot]

Originally Posted by bmw_solid

I've received the kit and its pretty straight forward but not a kit I could make my self as I would have needed to source a customer harness for the switch, and a custom pin for the wire to connect to the CAS connector.

Connection is simply the following:

The harness connector (which goes into the switch) has 3 wires coming out:

One wire is for the ground
One wire is for the backlight/illumination for the button when lights are switched on

^^ These two wires can basically be connected using scotch locks or doing a bit of soldering

The last wire, as mentioned at the start, is the one which goes into slot 39 of the CAS. This wire has the correct pin crimped on it, as part of the kit by 'ccfj' on M3 Cutters forum. The pin basically needs to be pushed into slot 39 of the CAS harness.

Its has simple a that. Although, I would personally remove the battery before taking the CAS harness off as the CAS is a critical ECU of the car...

Bit of a thread revival, but looking to fit this switch to my LCI E90.

I've found the wiring diagram stating that PIN 3 of the Boot Release switch goes to PIN 39 on the CAS (below - look for S204)



But do we know where the lighting pin goes?
I presume there is a ground comb nearby that I can tap into - but is that PIN 1 or 2 switch-side?

Any help would be great.

EDIT; found the wiring diagram.


Boot Release Switch
PIN 2 (0.35mm2 wiring - grey/red) to X908 - this is for the internal illumination
PIN 3 (0.35mm2 wiring - grey/brown) to PIN 39 on X13376 (CAS)
PIN 4 (0.35mm2 wiring - brown/white) to X1108 - earth

I'm unsure what X908 is, I think it's a junction of some description down in the drivers footwell.
Having checked further wiring diagrams, I'm going to trace PIN 48 from X14261 on the FRM to this location, and go from there.

ALTERNATIVELY, if like me, you have a switch with only PINS 1-3.
PIN 1 (0.35mm2 wiring - grey/red) to X1019 - this is for the internal illumination
PIN 2 (0.35mm2 wiring - brown) to X1108 - earth
PIN 3 (0.35mm2 wiring - green/black) to PIN 39 on X13376 (CAS)





Done

[LORDD]

Originally Posted by Nickdot

Bit of a thread revival, but looking to fit this switch to my LCI E90.

I've found the wiring diagram stating that PIN 3 of the Boot Release switch goes to PIN 39 on the CAS (below - look for S204)



But do we know where the lighting pin goes?
I presume there is a ground comb nearby that I can tap into - but is that PIN 1 or 2 switch-side?

Any help would be great.

EDIT; found the wiring diagram.


Boot Release Switch
PIN 2 (0.35mm2 wiring - grey/red) to X908 - this is for the internal illumination
PIN 3 (0.35mm2 wiring - grey/brown) to PIN 39 on X13376 (CAS)
PIN 4 (0.35mm2 wiring - brown/white) to X1108 - earth

I'm unsure what X908 is, I think it's a junction of some description down in the drivers footwell.
Having checked further wiring diagrams, I'm going to trace PIN 48 from X14261 on the FRM to this location, and go from there.

ALTERNATIVELY, if like me, you have a switch with only PINS 1-3.
PIN 1 (0.35mm2 wiring - grey/red) to X1019 - this is for the internal illumination
PIN 2 (0.35mm2 wiring - brown) to X1108 - earth
PIN 3 (0.35mm2 wiring - green/black) to PIN 39 on X13376 (CAS)





Done

I have seen this kit on eBay is this like the one you bought ?
https://www.ebay.co.uk/itm/325227771...mis&media=COPY

[Wtk17]

Thread revival!

I have plugged into pin 39 of cas, I am struggling to find the 12v and the ground near the drivers footwell. Any tips or clues?

Also, should the switch work with just the pin in 39 or does it require all three cables to work?

Thanks for any help in advance

[Wtk17]

For future users, the easy way to do this is to plug into the driver footwell module, which is behind the OBD port.

Unscrew the engin open latch, unscrew the second screw hiden by it.
The driver footwell module is right there.

The first visible connector is the X14259, facing towards the driver.
Pin 5 of this connector is ground
Pin 21 is instrument lighting

Easiest install, no need to remove driver footwell or rout anywhere far away, this is right behind the switch itself.

Remove trim above driver footwell for more room.

[MrCav330d]

When you fitted the earth and lighting wires, did you just re-pin the existing earth and illumination wires that are already installed in the X14259? Thanks

Originally Posted by Wtk17

For future users, the easy way to do this is to plug into the driver footwell module, which is behind the OBD port.

Unscrew the engin open latch, unscrew the second screw hiden by it.
The driver footwell module is right there.

The first visible connector is the X14259, facing towards the driver.
Pin 5 of this connector is ground
Pin 21 is instrument lighting

Easiest install, no need to remove driver footwell or rout anywhere far away, this is right behind the switch itself.

Remove trim above driver footwell for more room.