[E90DC]

Hopefully someone can point me in the right direction. I have a 2011 LCI E90 sedan. The trunk has decided to stop operating, key fob, latch, interior button...nothing. Valet switch has been checked. I'm getting an error for central locking, A739 PL2

I can't seem to identify a fuse that would cause this. Any advice?

[gbalthrop]

Originally Posted by E90DC

... 2011 LCI E90 sedan. The trunk has decided to stop operating, key fob, latch, interior button...nothing... A739

There is NO separate fuse for the Trunk Lid Locking Drive. "A739" Definition, per BMW Fault Code Lookup, and also ISTA:
A739 | JBE: Central-locking drive, rear lid | jbbf70
My SWAG, without further testing, is THAT Code means the JBE/JBBF is receiving the "UN-Latch" Input from either or both the Interior Button, or the Switch on the Boot Lid, above the Tag, but cannot operate the Latch.

Questions:
1) I presume ALL 4 doors and the Fuel Filler Flap all lock/ unlock with Central Locking Button OR Remote Key?
2) You say "car thinks it's open" -- what causes you to say that? Is the trunk light on? (IF you can see into trunk). Is battery losing charge as if trunk light were on?
3) Is there ANY sound from trunk lock/latch area when you Lock, Unlock, or use Trunk release button on Remote Key?
4) Do ALL lights on Trunk Lid work properly? Reversing, Tag, Side?
5) Do you have INPA or ISTA, or any Scan Tool or Diagnostic Software that allows you to test function of each button (Central Locking INPUTS)?

While there are several things that COULD cause the issue you describe, perhaps most LIKELY cause is a broken ground or Latch Release wire in the Loom at the Trunk Hinge Plane. That's why I suggested checking to see that all lights on the boot lid work. If one of those two wires is broken, Manual release by pulling the plastic emergency release handle is your ONLY means of opening trunk, unless you drill a hole in lid at just the right place (I have a Wagon and don't have to worry where that place is ;-).

1) Got a portly friend? Get him to sit on trunk lid as you press Trunk Release button, by door or on Fob. If Trunk Latch needs adjustment (too tight) and that is what is preventing "UnLatch" then you will be able to raise lid (when he gets off ;-).

2) There is a mechanical latch Release/Pull on the rear inside face of the trunk lid. Do you have access to the Trunk so you can see in when you drop the center armrest on the rear seatback/ squab?

3) There is a way to "hotwire" the trunk latch, IF the "trigger" wire from JBE to latch is intact, if the Ground wire is intact, AND if the latch is electrically functioning. However, if ALL other locks work properly, it is probably NOT the case that the wires and latch are electrically functional.

Please let us know if you can gain access to the boot (at least to see inside) by dropping the Armrest.
George

[E90DC]

1)Yes, all others are working
2) Trunk warning light comes on when I drive
3) No sound at all.
4) Actually, no. I started having an issue with the left inner tail light on the trunk lid.
5) I don't


I'm thinking a wiring issue might be most likely.

I do know I can get in. A bit more backstory...I was due to replace the battery today, I knew it was on its last legs. I went out to get to work, opened the trunk to get something, closed it, went to start the car to move it and it was dead. Figured, well, guess i'll pop the trunk and replace the battery here and now....and that's when the trunk failed to open.

I don't have a pass through, but was able to magyver my way in by removing the back seat bottom, undoing the 2 T50 bolts and hooking the emergency release. Got the battery replaced, but trunk still wasn't working. Unfortunately, we only have 1 car and had someplace to be with our toddler, so everything had to go back together to get the carseat in.

I suppose tomorrow I'll be breaking back into the trunk to check the wiring loom.

[gbalthrop]

Hope you NOW have a LONG cord/ Rope from mechanical "Pull" loop into rear seat area.

There are about 3 different wiring diagrams you have to look at to understand HOW the entire Trunk Latch, Lock, Light works. If you would like the diagrams to refer to in order to test the wiring when you "go back in", just give me the Last-7 Characters of your VIN so I make sure I have correct info for YOUR model.

You need:
1) Central Locking Inputs;
2) Central Locking Drives; and
3) Interior Lights (for boot light).

If you have broken wiring in the Loom(s) at the Trunk Hinge Plane, you may want other diagrams, such as Reversing Lights, Side Lights, etc. You can "PROBABLY" get by just splicing broken wires without testing/ knowing function, but....

George

[E90DC]

I really should have tied a cord to it. I do still have my hook tool I created. Once I undo the seat back bolts, I should be able to hook it again. Also, now that I know how the latches up behind the headrests work (figured it out from the open trunk after I popped it), I can probably get those with a long screwdriver and just climb right in.

Last 7 of the VIN are A444506

[Lone-Wolf's Mom]

Dec 2021 • 2008 328i • I’m having the same issue with my trunk and have no clue what’s going on or how to fix it!?

One day I just noticed my trunk wouldn’t open.. about the first three times I pressed the trunk button on the key and from inside it made a sound like it unlocked but after that, no sounds. Also, when I’m driving I get the “open trunk” notification on the dash constantly.
The next odd thing that started with this issue, is the next day I noticed my trip miles, clock, & date were reset. And now this happens every time I get into my car. It will reset like if someone took the cable off the battery and put it back on. and lastly it now says my rear tail light is out, which it is, the one not on the trunk door. But I’ve recently replaced that exact one. I’m not sure what’s going on or how to fix it. Also valet lock is set to unlock & I don’t have fold down seats for trunk access.

I removed the bottom seats or the rear seats and started to try to remove the backrest part, but the bolts are too tight for me and also am not sure where to go next if I remove the backrest since there’s metal there or something.

ANY ADVICE???

[Lone-Wolf's Mom]

Originally Posted by E90DC

1)Yes, all others are working
2) Trunk warning light comes on when I drive
3) No sound at all.
4) Actually, no. I started having an issue with the left inner tail light on the trunk lid.
5) I don't


I'm thinking a wiring issue might be most likely.

I do know I can get in. A bit more backstory...I was due to replace the battery today, I knew it was on its last legs. I went out to get to work, opened the trunk to get something, closed it, went to start the car to move it and it was dead. Figured, well, guess i'll pop the trunk and replace the battery here and now....and that's when the trunk failed to open.

I don't have a pass through, but was able to magyver my way in by removing the back seat bottom, undoing the 2 T50 bolts and hooking the emergency release. Got the battery replaced, but trunk still wasn't working. Unfortunately, we only have 1 car and had someplace to be with our toddler, so everything had to go back together to get the carseat in.

I suppose tomorrow I'll be breaking back into the trunk to check the wiring loom.

———————————

Where did you enter with the tool to hook the latch? What did you use as the tool?

[gbalthrop]

First, my apologies to E90DC if I "left you hanging" in September. Somehow assumed you had ISTA and could find the needed wiring diagrams yourself. If any issues or questions remain, Please Post Back.

"Lone-Wolf's Mom", please provide answers to following & I'll provide info this evening:

1) What are Last-7 Characters of VIN (for correct ISTA wiring diagrams)?
2) What if any other functions on trunk lid do NOT work? e.g. do Reversing Lights, Tag Lights, ALL Parking/Side Lights work? Does Trunk release button at Driver Door work?
3) What "CC-ID Codes" does "Check Control" procedure display?
4) If you have Scan Tool or Diagnostic Software that can read Fault Codes in FRM Module, what codes are present?
George

[andrewbr]

Originally Posted by Lone-Wolf's Mom

Dec 2021 • 2008 328i • I’m having the same issue with my trunk and have no clue what’s going on or how to fix it!?

One day I just noticed my trunk wouldn’t open.. about the first three times I pressed the trunk button on the key and from inside it made a sound like it unlocked but after that, no sounds. Also, when I’m driving I get the “open trunk” notification on the dash constantly.
The next odd thing that started with this issue, is the next day I noticed my trip miles, clock, & date were reset. And now this happens every time I get into my car. It will reset like if someone took the cable off the battery and put it back on. and lastly it now says my rear tail light is out, which it is, the one not on the trunk door. But I’ve recently replaced that exact one. I’m not sure what’s going on or how to fix it. Also valet lock is set to unlock & I don’t have fold down seats for trunk access.

I removed the bottom seats or the rear seats and started to try to remove the backrest part, but the bolts are too tight for me and also am not sure where to go next if I remove the backrest since there’s metal there or something.

ANY ADVICE???

The trunk issue recently happened to me. I drove over some bumps which apparently jiggled the trunk enough that I could open and re-close it. It's silly but it worked for me.

Can't help you with the other things but it does sound like a battery connection issue, would be good to check that when you get the trunk open.

[ctuna]

The trick of stimulating the trunk latch from the fuse box with an external
battery is in the following thread .

http://www.e90post.com/forums/showthread.php?t=986670
Entry 14

If that doesn't work try Cave Man techniques.

My trunk open sensor doesn't activate sometimes if the trunk/hatch with it fully
closed , at least it appears to be , but it seems to be fully closed and latched.
I just open and close again and it then senses it.

The general rule is always know that you have a good battery
before assuming it's something else .
The electronics in these cars don't work if the battery is to low
or the charging rate is to high and there are a lot of electronics.

[Lone-Wolf's Mom]

Originally Posted by Lone-Wolf's Mom

Dec 2021 • 2008 328i • I’m having the same issue with my trunk and have no clue what’s going on or how to fix it!?

One day I just noticed my trunk wouldn’t open.. about the first three times I pressed the trunk button on the key and from inside it made a sound like it unlocked but after that, no sounds. Also, when I’m driving I get the “open trunk” notification on the dash constantly.
The next odd thing that started with this issue, is the next day I noticed my trip miles, clock, & date were reset. And now this happens every time I get into my car. It will reset like if someone took the cable off the battery and put it back on. and lastly it now says my rear tail light is out, which it is, the one not on the trunk door. But I’ve recently replaced that exact one. I’m not sure what’s going on or how to fix it. Also valet lock is set to unlock & I don’t have fold down seats for trunk access.

I removed the bottom seats or the rear seats and started to try to remove the backrest part, but the bolts are too tight for me and also am not sure where to go next if I remove the backrest since there’s metal there or something.

ANY ADVICE???

SOO since my last post ive fixed the issue and have had new issues pop up of course. but it turns out I could've gotten into my trunk the whole time. I tried with the physical key once and weeks later just moments. before drilling holes into the sheet metal behind the back seats, I stuck my key in the trunk and turned and nothing and tried once more with more oomph and actually opened it. I wanted to cry cause I felt so stupid. ..BUT I did have to strip wires and find the broken one to solder it back together and trunk works perfect again .

[erickrayos]

Sorry for reviving this thread. I've been having the same problem as some of you.

The first symptom was the left side tail lights on the trunk lid stops working if the trunk lid gets closed a bit hard and the trunk won't open with remote or the trunk latch switch. I have to use my key to actually open the trunk and re close it and it'll normally work properly again.

Today that stopped working altogether. The right side tail light on the trunk is working properly, so I thought this will be a wiring issue but upon removing the trunk liner, initial visual inspection of all the wires I can see they seem to be no break on any wires ther I can see.

Not sure where to check because before as I said if I open and close it I can see the light on the left side turn on as I go lower the trunk lid. Any specific spots to check the wiring at? Or diagram since I tried googling and can't find a diagram or ipb of the wiring on the trunk side.

[bmwbob89]

Check the wires in the snorkel where they go into the trunk lid. They bend every time you open the trunk.