Trunk won't open with the key fob

[Cool Z4]

Hi there. I just ran into a problem yesterday. My trunk won't open using the key fob or pushing the button in the car. I can open it with the key in the trun k lid, though. Other things not working, trunk light, alarm won't sound when locking anymore. I tried to find a fuse that may be the culprit, but no luck. Anybody know which fuse it may be or any other reasons? Oh, same thing happens with the spare key as well.
Thanks...

 

[mister_roger]

I have the same problem too. One day, all the sudden, my key fob and interior button no longer functioned. Trunk still opens with the key manually though.

trunk light stopped working about a month before this, along with the center third brake light. I am wondering if this has something to do with the ground wires, as they all appear to be on similar circuits. I didn't notice any shorted out wires when I did a brief visual inspection, but I'd suggest you look at the wire harness coming from the trunk lid to the body a the lower right corner. Another possible fault could be the trunk release mechanism

If you are good with wiring diagrams and feel like going more in-depth, here is an excellent resource for BMW wiring diagrams
http://wds.west.lv/

Hope this helps. Let us know if you figure out what the problem is.

 

[Yal]

I have the same issue and was assuming that the electrical part of the locking mechanism was broken on mine. Same thing happened to me about 64K into the car. If I read realoem correctly, the replacement is about $50, but I haven't done it yet. I haven't taken mine apart yet to see if there is a logic change on the switch when the button is pushed.

 

[WaZZZZman]

Did you test with more than one key fob?

 

[Yal]

My answer to this is yes, and with the button inside the car not working, it was pretty apparent that it was not the fob, but I did it anyway. I also did a reset of the fobs.

 

[Cool Z4]

I got mine fixed!!
What the mechanic did was to replace the locking mechanism for $67 US. That did NOT solve the problem, so he went after the problem and told me that he had to ADD a ground wire. Where he did this, I don't know, but it works once again. :driving:

 

[mister_roger]

Hmm, sounds like a shorted ground wire somewhere in the main harness. I'll have to bring mine in sometime to get this fixed -- probably suggest this ground wire solution as well.

Glad to hear you got it fixed.

 

[IMZ4N]

Cool it works. Glad it had nothing to do with the body control module. :roll:

 

[joey19561]

Has cool z4 ever learned where the grounding issue was?

 

[Zedpete]

i had this problem (although interior footwell button still worked but key didnt)

clearing old historic fault code re the lock actuator fixed the issue for me