Dreaded convertible top error A68D microswitch

[BMW764]

So I was closing the convertible top and about three seconds before it was complete, the error came up. I’ve done a decent amount of research and I’m going to try to see if I can repair the wire harness first.

The problem is that the top naturally fell down on its own and now the window is locked to the body. Does anybody know how to release the window? That way I can lift the top up and work on the wires more easily

[BMW764]

Update I got the top to unlock. The right side switch does show inactive when I press and depress it. There is no noticeable damage to any wires at all so I’m going to try and replace the switch and see what happens

[RobbiZ4]

Originally Posted by BMW764

The right side switch does show inactive when I press and depress it. There is no noticeable damage to any wires at all so I’m going to try and replace the switch and see what happens

Don't touch any of the 2 microswitches in the roof shell, they never fail! You won't be able to get a new one mounted correctly.

But a wire is broken or there is a short between two wires in the upper bow of the hydraulic harness. 2 wires on the lef, 2x2 wires on the right. It's in the absolut invisible area in the roof shell, not in the lower bow you might have inspected.

Have a look at this as well as similiar threads:
https://z4-forum.com/forum/viewtopic...roken#p2027081

Search results:
https://z4-forum.com/forum/search.ph...&submit=Search

[BMW764]

Really appreciate that advice Robbiz4. I decided yesterday that I was going to do more research at night time when I have some more time. I saw a lot of your posts, this is exactly what I was going to do today. I will inspect the whole wiring harness. I’m sure there’s a short somewhere.

I have a love-hate relationship for this car. Every time I get one problem fixed another one comes up.

[B21]

Originally Posted by BMW764

Really appreciate that advice Robbiz4. I decided yesterday that I was going to do more research at night time when I have some more time. I saw a lot of your posts, this is exactly what I was going to do today. I will inspect the whole wiring harness. I’m sure there’s a short somewhere.

I have a love-hate relationship for this car. Every time I get one problem fixed another one comes up.

Welcome to the Pleasure Dome….many seem to have pleasure and pain in what seems equal measures..hope you get it fixed..

[RobbiZ4]

Originally Posted by BMW764

I will inspect the whole wiring harness. I’m sure there’s a short somewhere.

I'm pretty sure you can't identify it visually, it has to be measured. The issue is ALWAYS on the single point marked in the linked picture, nowhere else.

Most of the broken or shorted wires only have temporarily faults depending on their bending angle while moving the roof shells. Keep in mind, that each pair of sensor wires are individually taped. Another taped fabric hose covers the whole package of 2 hydraulic hoses, 1 rear window heating wire and the taped pairs of sensor wires.

[javis20]

Originally Posted by B21

Welcome to the Pleasure Dome….many seem to have pleasure and pain in what seems equal measures..hope you get it fixed..

So true.

[BMW764]

Ok issue I am having now is I can’t get the top to lift higher than 6 inches. I assume it has some pressure from the hydraulic system in it, any way to release this pressure?

[BMW764]

Sorry to keep the thread going, I’ve tried searching, and I can’t find anything. If anyone has a good suggestion here how to relieve the hydraulic pressure, or a video on how to perform this repair would be so much appreciated. I’m just struggling to find how to access the wire bundle, which is pretty deep within the structure of the hardtop frame. All the images I see online have the trunk part open which exposes the wire harness, and unfortunately, I can’t get my convertible to retract that far.

[RobbiZ4]

Always bring the locking system of the trunk lid into it's service mode:
push both flippers on the right and on the left until the softclose motors start closing, then lay down the trunk lid. Doing this, you are always able to get into the trunk and to the technical components. Never touch the emblem button on the lid when it's locked this way while working on the roof.

There are 2 brass valves (screws) on top of the hydraulic pump. The one to the front of the car releases the hydraulic pressure from the rear roof shell as well as the main structure.
The rear valve releases the hydraulic pressure from the rear frame below the trunk lid.

These valves may only be opened for a max of 2 turns, not more!

[BMW764]

Originally Posted by RobbiZ4

Always bring the locking system of the trunk lid into it's service mode:
push both flippers on the right and on the left until the softclose motors start closing, then lay down the trunk lid. Doing this, you are always able to get into the trunk and to the technical components. Never touch the emblem button on the lid when it's locked this way while working on the roof.

There are 2 brass valves (screws) on top of the hydraulic pump. The one to the front of the car releases the hydraulic pressure from the rear roof shell as well as the main structure.
The rear valve releases the hydraulic pressure from the rear frame below the trunk lid.

These valves may only be opened for a max of 2 turns, not more!

Ok thank you for the help so just to confirm, I want to release pressure only on the front screw correct? The part of the hard top that is stuck is the part which has the rear window. Like I stated before I can only prop it up a few inches and I’d like to get this to move freely up and down so I can move around the wire harness.

Also regarding the trunk, I was not able to open it with the key fob or unlocking and using the emblem. I had to get creative and use a hanger to fish through a looped string that I could grab with a second hanger to release the emergency handle in the rear.

[RobbiZ4]

Sorry for my late resonse.

Originally Posted by BMW764

...just to confirm, I want to release pressure only on the front screw correct? The part of the hard top that is stuck is the part which has the rear window.

Correct.

Originally Posted by BMW764

Also regarding the trunk, I was not able to open it with the key fob or unlocking and using the emblem. I had to get creative and use a hanger to fish through a looped string that I could grab with a second hanger to release the emergency handle in the rear.

And feel as a lucky guy as your Z4 is an US one. In Europe there is no emergency handle mounted in the trunks.

Originally Posted by BMW764

...to release the emergency handle in the rear.

That is ok. And now you have to close it logically only at the two "flippers" (read my former post) and then lay it "only" down on the body. This way the CTM "sees" a logically closed trunk, but you are always able to get into it.

[BMW764]

A good news update! I found the break in the wire, it’s actually on the microswitch wire portion of the connection.

I was playing around and squeezing the wire in places while checking the microswitch functionality in my protocol live data. Eventually I got the connection back. So I used a clamp to hold pressed down the wires where I found the break just to get the roof closed. As soon as it starts moving open the wire disconnects again and throws the code.

I’m going to do a permanent fix later on by soldering the wires, but for now, at least it’s not bonging at me while driving. Plus it’s winter here so I don’t really need the top much anyways..

[B21]

Originally Posted by BMW764

A good news update! I found the break in the wire, it’s actually on the microswitch wire portion of the connection.

I was playing around and squeezing the wire in places while checking the microswitch functionality in my protocol live data. Eventually I got the connection back. So I used a clamp to hold pressed down the wires where I found the break just to get the roof closed. As soon as it starts moving open the wire disconnects again and throws the code.

I’m going to do a permanent fix later on by soldering the wires, but for now, at least it’s not bonging at me while driving. Plus it’s winter here so I don’t really need the top much anyways..

Result..well done for perseverance..

[John Tanglewoo]

Originally Posted by BMW764

So I was closing the convertible top and about three seconds before it was complete, the error came up. I’ve done a decent amount of research and I’m going to try to see if I can repair the wire harness first.

The problem is that the top naturally fell down on its own and now the window is locked to the body. Does anybody know how to release the window? That way I can lift the top up and work on the wires more easily

To release the window, you might want to check for a manual override or an emergency release lever around the convertible top mechanism. Your car's owner's manual could be a treasure map for finding that release. If you don't have the manual handy, a quick online search for your specific model's convertible top manual release might do the trick.