Left Turn - Roof Closed, Momentary Convertible Top Error "Bong"

[Christopher72]

I just pulled my first: CVM/CTM [CTM_89] | A68B: Microswitch, roof shell 2 closed, left error off of ProTool today.

I had received a "bong" and a roof warning on the dash with the top closed... but only on a left turn. I've not seen any top opening, closing or locking issues, so I guess it's time to figure it out before there is one. Tons of threads on this and I see that Robbi_Z4 is the master. I just wish he was a YouTube video superstar as well.

Getting into this, from hours of reading threads that @Robbi_Z4 has participated in, I'm likely to need to replace some wires that are injured that are lashed into the robot arms behind the rear shell. Recommendations of specific flexible patch wire quality/links? using a mesh or lap solder splice? I plan to get a good look tomorrow, take a few pictures, but not start tearing apart loom covers until I have the replacement wire needed. I'm sure both sides should be checked, but is A68B on the left as I understand.

I've also read through viewtopic.php?p=1905886. I'm feeling more dangerous than confident.

My 54377228585, 54377228586 are on order, in following the master's replacement recommendations - not expected to fix this problem. I've replaced the fish relays a bit ago and checked the condition of the hydraulic pump to be good. All of my trunk seals are intact and flexible, and my taillights are original. My point being that I take it all seriously after reading The Book of Robbi_Z4

I hear that this is almost like Covid19, everyone is going to get it sometime, but some ppl get worse symptoms. I didn't get into a high mileage Z4 blind, and I absolutely love driving this car. Warmed it up and took some nice pulls over 110mph on appropriately empty stretches of road. D**n that engine sounds good.

[javis20]

Replacement of the micro switches is very easy. Here is a video I did.

https://youtu.be/qcwZC1uah_o

[Christopher72]

Replacement of the micro switches is very easy. Here is a video I did.

To follow:
-- Move the cover to find my nuts, paint my nuts, get my nuts off.
-- Two screws, if it's in too tight, drill them, they are nice and soft. (Do the switch replacement)
-- Align my nuts with the painted holes... How many lb/ft to torque my nuts?
Sorry, couldn't resist nuts humor.

Great quality in your video - it's very helpful for me to see the work in motion!

Any recommendation on a brand of flexible wire for the microswitch/hall switches in the robot arms behind shell 2 - something like this wire designed for automation robots? 18, 20,24 awg?

https://www.automationdirect.com/adc/sh ... gnal_cable
https://www.grainger.com/product/CHAINF ... -CF5-2TZK1

[smorris_12]

Silicone rather than PVC coated might be best. "Extra flexible cable" or "test meter lead cable" (or wire instead of cable) ought to turn up something cheap and cheerful on eBay (I presume the site you linked to will want to sell you industrial sized quantities!)

[RobbiZ4]

I just pulled my first: CVM/CTM [CTM_89] | A68B: Microswitch, roof shell 2 closed, left error off of ProTool today.

That's typically a broken wire in the upper bow of the hydraulic harness. On the left there are 2, on the right there are 2x2 wires. Mostly all in the same weak condition. 0.25mm² (~23AWG) LIFY wire quality is the better choice, not silicone. LIFY is high flexible, where as silicone is more temerature resistant.
https://www.litze24.de/produktinfos/kab ... n/awg.html

Replacing the two microswitches in the trunk in addition to your problem(s!) behind the roof shell is a good idea.

[Christopher72]

Thanks for the responses! Yes, I have ordered the two trunk switches (54377228585, 54377228586).

Looking for LIFY wire that's available here in the USA is quite the search, is this what you are referring to?
https://www.soselectronic.com/en/produc ... 175-216760

I've also ordered the two Shell 2 micro switches (54377227397, 54377227398), and a 135i Hall Sensor (54347190735) so that I have them if needed in my parts cabinet. The Z4 specific Hall Sensor was avoided because of its abusive price.

[RobbiZ4]

Looking for LIFY wire that's available here in the USA is quite the search, is this what you are referring to?
https://www.soselectronic.com/en/produc ... 175-216760

Perfect. I've bought the same quality from TruComponents.

I've also ordered the two Shell 2 micro switches (54377227397, 54377227398)...

If anyhow possible avoid to touch these 2 switches as they never fail. They are difficulty to mount (plastic pins to weld) and I only replace them if the rear roof shell got dismounted before.

[Christopher72]

If anyhow possible avoid to touch these 2 switches as they never fail. They are difficulty to mount (plastic pins to weld) and I only replace them if the rear roof shell got dismounted before.

Thank you -- I'll just hang on to them in case they ever do become the problem. I'll accept your experience in not poking the beehive.

[RobbiZ4]

Morning Chris,

There is a description, how to properly dismantle the rear roof shell. Topic 4 on the following link.
viewtopic.php?t=122363

Remove the ceiling first, then carefully the 2 connectors of the rear window.

Mark a circle around the current position of each screw with a white or silver Edding pen (2x2 vertically, 2x1 horizontally on the rear).

I use a heatgun ( 180°C) with a 5mm nozzle to warm up the 6 screws of the shell as they are glued. These torx 40 screws have to be replaced with new ones of the following set: 54377220536

https://www.realoem.com/bmw/enUS/part?i ... 4377220536

6 small zip bags numbered 1..6 to store the individual number of spacers above the screws as well as the old screws are recommended.

Work carefully and not in a hurry.

Good luck.

[flybobbie]

Of course one answer...don't make left turns.

[RobbiZ4]

...don't make left turns.

[Christopher72]

There's that... I could use FedEx, DHL, or UPS routing software to avoid left turns.

Or just leave the top down all of the time -- Just don't stop when it rains.

Waiting for parts....

[Christopher72]

There is a description, how to properly dismantle the rear roof shell. Topic 4 on the following link.
viewtopic.php?t=122363
...
Good luck.

Thanks!

[Christopher72]

Installed the switches in the boot. ProTool tells me the error is gone and everything works. *woot*

I think that 50% of the trim plastic fasteners popped apart... replaced them with new ones. It seriously took more time to get to the switches than it did to do the swap.

I did have to splice the old connector onto the new parts. Removing the M3 screws without needing to drill them using a hex driver rather than an L shaped wrench. Remember to scribe the bolts with a paint pen to ensure you don't have to adjust the closure afterward. Will watch for additional error. Thanks for your help Robbi and Jarvis.

[RobbiZ4]