HELP roof malfunction/weird operation: 43/44 Drive, cowl panel, open circuit

[Isoveli]

I just purchased my first Z4 sight unseen. I sent a friend to test it and he said the roof worked normally when he tried it.

However, upon receiving it the roof works completely wacky, almost backwards:

This is similar/same to a previous post, but with no solution: https://z4-forum.com/forum/viewtopic.php?t=115626

1. Upon pressing the open button, the latches disengage, but it gets stuck and makes a buzzing noise.
2. To continue opening, one must spam the open and close buttons to open it. AND keep the CLOSE button pressed to open.
3. Upon fully opening, the buzzing noise continues.
4. To reopen, the buttons must be spammed a few times and the latches disengage. AND keep the open button pressed to close.
5. To relatch, one must switch from pressing open to close. AND press the roof forward to engage as it doesn’t go forward enough and line up.

Opening: https://youtu.be/YYcbANRgK6s

Closing: https://youtu.be/7k6BulRmSPo

Operation with scanner connected: https://youtu.be/U36Be1jjbmY

It throws two codes from the roof module: 43 and 44, both reading Drive, cowl panel, open circuit.

Would anyone have any advice on how I can start diagnosing?
I was attempting to follow this thread but its almost impossible without pictures. https://www.zpost.com/forums/showthread.php?t=925098

If there’s any more info needed, or videos/pics that could help let me know!

Thanks to everyone in advance!

[JAS1169]

Wow!

Your #1

1. Upon pressing the open button, the latches disengage, but it gets stuck and makes a buzzing noise.

The fact that when you push top down the roof releases from the windshield indicates that the wiring is more than likely in the correct order. Your #2 thru #5 are unbelievable.

The buzzing noise is the top motor running.

Your problem is electrical. This could be caused by a number of different things.

#1 Bad convertible controller (white box behind Driver side USA model)
#2 Sensor(s) damaged or broken, there are 4 sensors which feed information into the convertible controller and tell it where the roof is during the opening/closing.
#3 the wiring harness to the sensors have issues.

When you pushed top down and the roof released there are two sensors at the front of the top which should start the roof down. This won't happen if the convertible controller has gone bad/ the sensors has an issue or the wiring between the sensor and controller has been broken.

I'd currently go to the white convertible controller and spray male/female plug in's with electrical contact cleaner. I'd also check for any black electrical tape which would suggest a prior owner was fooling around with that area. Finally, make sure that the plugs are firmly on and then check the top's operation.

However, after watching your two youtubes and all of the Butten pushing I'd strongly suspect a bad controller. I'm not saying it can't be a sensor or a broken wire in the harness. However, they generally aren't fixed by pushing up/down buttens

[JAS1169]

I noticed that your windows came down halfway during the top down/top up action. Do you known if the car had an aftermarket device called Gap-tech installed on it? I believe this was a device market in the UK which allowed the top on the Z4 to be opened/closed using the key fob.

Apparently, these Gap-Tech devices can cause really unusual problems. I have no hands on experience at all with these so I can't help with where it would be installed on the car.

Please read: https://z4-forum.com/forum/viewtopic.php?t=95698

In the above posting they mention the windows coming half-way down on a Gap-tech outfitted car and that's why I asked if your car has a gap-tech device. Generally, the window on a Z4 only drops a little during the convertible movement.

[zed_fan]

Drive, cowl panel refers to the roof latching motor. That is the part you can see exposed in your headliner panel in your video, it controls the hooks that lock your roof. I had those codes and replacing the motor fixed it for me. But it could be anything JAS1169 has said, too.

[Jays.-.beemah]

Originally Posted by Isoveli

I just purchased my first Z4 sight unseen. I sent a friend to test it and he said the roof worked normally when he tried it.

However, upon receiving it the roof works completely wacky, almost backwards:

This is similar/same to a previous post, but with no solution: https://z4-forum.com/forum/viewtopic.php?t=115626

1. Upon pressing the open button, the latches disengage, but it gets stuck and makes a buzzing noise.
2. To continue opening, one must spam the open and close buttons to open it. AND keep the CLOSE button pressed to open.
3. Upon fully opening, the buzzing noise continues.
4. To reopen, the buttons must be spammed a few times and the latches disengage. AND keep the open button pressed to close.
5. To relatch, one must switch from pressing open to close. AND press the roof forward to engage as it doesn’t go forward enough and line up.

Opening: https://youtu.be/YYcbANRgK6s

Closing: https://youtu.be/7k6BulRmSPo

Operation with scanner connected: https://youtu.be/U36Be1jjbmY

It throws two codes from the roof module: 43 and 44, both reading Drive, cowl panel, open circuit.

Would anyone have any advice on how I can start diagnosing?
I was attempting to follow this thread but its almost impossible without pictures. https://www.zpost.com/forums/showthread.php?t=925098

If [...]

Look I think we had the same problem. If it is blinking red and won’t go then it is most likely the same thing. It’s going to be a wore that snapped off. You’re gonna put the top up to where it is in the middle, unscrew the cowl and follow the lines over the driver side. You may have to cut the black tubing that covers it. Once there get some spare wire and solder it back together then wrap it and it should be good