Roof issue and fault codes - help please

[Big Bad Boris]

I guess with the sun coming out, this is the time of year for a few roof issues for us fair weather drivers as we open the tin lid for the first time in a few months.

So I opened the top on Thursday, there was a bit of a clonk and it appeared the boot lid had not opened enough to allow the other sections to pass, so the whole thing became stuck half open. With help from my daughter operating the up and down buttons and some gentle encouragement from after some open/close jiggling we finally got the roof fully down… and then back into the closed position where it has stayed.

I put my code reader on it yesterday and these are the three things that came up;

- JBE junction box electronics A6CF AUC Sensor
- E721status sensor AUC, 2DO
- A696 Hall sensor, open circuit, closing movement rear end module

I wonder if these codes are indicative of a genuine issue (probably a sensor of some kind?). Or is it possible the codes were created due to the myriad of battery issues that can occur on the trusty E89.

Additional info, battery is less than two years old and the legendary salmon relays were changed when I bought the car, so also less than 2 years old. I did put the CTEK on the battery all day yesterday so it’s definitely fully charged now, but I don’t want to try it again until I get some more expert opinion on what the root cause might be from the good folk here.

As always I’d appreciate any help from you fine Zedding people

 

[Stash36]

Hi mate, no replies so far...possibly because there are threads upon threads with this info if you search your Hall sensor error, or possibly because you're called Big Bad Boris!

The first two errors look Air Con related.

Couple of vids below here on a696...not sure if this helps but keep searching on here, you'll find the answer.
Looks for posts by Robbi Z4, he is a roof expert based in Germany and he is THE knowledge on these things!

https://www.youtube.com/watch?v=PWhGr8EBnAM
https://www.youtube.com/watch?v=I0jdNtWzKoQ

 

[flybobbie]

 

[Big Bad Boris]

Finally I am back to trying to resolve this after a few goings on, including my turn with everyone’s favourite virus

I had and have read plenty of background information on the subject of of roof issues, particularly the great work and instruction penned by the legendary RobbieZ4. Sometimes for us less mechanically oriented bods it does become a little heavy going and seeing the wood for the trees is a little tricky.

My error code of “ A696 Hall sensor, open circuit, closing movement rear end module” appears to be generated by either of several micro switches or hall sensors.

Having tested again yesterday with my wife operating the buttons while I shout in panic, I ascertained the key issue seems to be the boot clam isn’t opening far enough (or perhaps quickly enough) before an attempt is made to stow the rear window, the window lifter arms then jam against the flexible sections on the boot lid, fortunately after a little manoeuvring the roof will go back up without issue or damage.

Given the fault code and what I have described, my question now is where do I start i.e. which is the most likely culprit in terms of micro switches and hall sensors? Again research tells me the micro switches on the right of the car are possibly the leading candidates with hall sensor(s), of which I believe there are 4, a close second,

 

[RobbiZ4]

Having tested again yesterday with my wife operating the buttons while I shout in panic, I ascertained the key issue seems to be the boot clam isn’t opening far enough (or perhaps quickly enough) before an attempt is made to stow the rear window, the window lifter arms then jam against the flexible sections on the boot lid, fortunately after a little manoeuvring the roof will go back up without issue or damage.

This issue is indeed a result of a rusty hall sensor on the rigth coupling fastener in the trunk. Typical indication is a small rusty/lightred line on the HS housing:


It is the rear hall sensor on the hydraulic ram. A picture of this unit in it's original mounted position can be found on the "E89: Retractable Hardtop (roof) Maintenance" thread. It is HS-1 with the red wire.
https://z4-forum.com/forum/viewtopic.php?p=1861524&hilit=ram#p1861524

First and most important step: put the boot lid into it's maintenance position, watch the linked video. Only this way you are able to get into the trunk while working on any roof components:
https://z4-forum.com/forum/viewtopic.php?p=1830459#p1830459


Getting the roof parts into the correct working position might be a challenge, as the boot doesn't open as intended. The boot lid frame has to be pushed into a vertical position, after it got unlocked hydraulically (that's important!) and got stopped before the "crash" happens. Then you have to open the rear brass valve on top of the hydraulic pump for a max. of 1.5 turns (not more, as it's locked mechanically), push the frame up (with a 2nd person!) and support it with i.e. an adjustable broom stick.

Take some photos of the original position of the zip tie on the middle of the right hydraulic ram, the black plug and the black hydraulic line below it!

You have to cut the zip tie on the middle of the right hydraulic ram. Take a tiny screwdriver, put it horizontally and very carefully between the ram housing on top and the black HS housing of the rear (hardly to see!) hall sensor, which is placed headover into the ram.

Can be replaced by a cheap HS from an E88.
https://z4-forum.com/forum/viewtopic.php?p=1899461#p1899461

New pins have to be crimped onto both wires or you have to solder the old plug on the new hall sensor. Kepp care on the colour orientation: colour to colour, brown to brown. 8) And keep care on the 4 pins of the new hall sensor to be placed correctly into the ram.

And don't forget to place a new zip tie over the black 2-pole plug as well as the hydraulic line, like you've documented before with a bunch of pictures!!!!

As last step, close the brass valve on the pump carefully by turning it back the 1.5 turns and fasten it with less manual force.

And don't forget or just replace the front hall sensor as well, as in most cases both HS intend to get rusty over years.

Good luck.

 

[Big Bad Boris]

Great response, thank you Robbie.

Just for clarity, as there are 4 hall sensors, the two to be changed are the two behind the ram on the right, inside the rear wing of the car right?

Thanks again, as I mentioned in my initial post, a legend of the forum

 

[RobbiZ4]

Just for clarity, as there are 4 hall sensors, ...

#3 is in the roof shell, #4 is for the luggage compartement on the bottom of the boot floor

...the two to be changed are the two BELOW the ram on the right, inside the rear wing of the car right?

Correct. But if possible, take a sharp photo of each HS front side like I did and post it here. I will get updated immediately, if you add another post.

...are the two below the ram on the right, ...

Responsible for your fault is only the rear hall sensor. The front hall sensor on the same ram is responsible for the short delay while closing the trunk lid.

 

[RobbiZ4]

Getting the roof parts into the correct working position might be a challenge, as the boot doesn't open as intended. The boot lid frame has to be pushed into a vertical position, after it got unlocked hydraulically (that's important!) and got stopped before the "crash" happens.

Thinking about this task again, I'm not sure if you will be able to get it solved as written above. It might be much more complex to drive the roof in this irregular situation. Always stop before a crash happens and come back to me.

To get the black pins of the internal trims removed the following tool (nail iron) is recommended instead of fighting with a screwdriver or a small pair of pliers!

 

[Big Bad Boris]

Thanks Robbie, I was wondering how I was going to get the roof into the ”maintenance position” with its current limitations.

I have ordered the suggested tool, it will arrive tomorrow, I will then endeavour to get some photos of the current condition of the hall sensors

 

[Big Bad Boris]

Just for clarity, as there are 4 hall sensors, ...

#3 is in the roof shell, #4 is for the luggage compartement on the bottom of the boot floor

...the two to be changed are the two BELOW the ram on the right, inside the rear wing of the car right?

Correct. But if possible, take a sharp photo of each HS front side like I did and post it here. I will get updated immediately, if you add another post.

...are the two below the ram on the right, ...

Responsible for your fault is only the rear hall sensor. The front hall sensor on the same ram is responsible for the short delay while closing the trunk lid.

Hi Robbie,

Just to let you know I haven’t disappeared after your valued response. Unfortunately I picked up a trapped nerve in my back (or something similar) immediately after your posts and have been physically unable to bend and twist into the boot of the car for over a week now.

I have my trim tool ready though :roll: Hopefully it will ease in the next few days (or after physio next week). Meantime a quick question, is it ok to remove the sensors to photograph them as you suggested just with the boot open i.e. with the roof itself not in the “maintenance position”?

 

[RobbiZ4]

OMG, hope your health will come back soon.

No, this is the wrong way!

At first open the BOOT LID, press the 2 flippers to get the 2 motors of the locking system started. If so, then the maintenan mode is activate. If not, have a look at germinator's video.

Then try to open the roof as far as no damage happens. The rear hall sensor is fixed by a zip tie, that is tricky to cut away. It has to be removed sorrowly to be able to take a photo.

 

[Big Bad Boris]

OMG, hope your health will come back soon.

No, this is the wrong way!

At first open the BOOT LID, press the 2 flippers to get the 2 motors of the locking system started. If so, then the maintenan mode is activate. If not, have a look at germinator's video.

Then try to open the roof as far as no damage happens. The rear hall sensor is fixed by a zip tie, that is tricky to cut away. It has to be removed sorrowly to be able to take a photo.

So today with the help of a knowledgeable engineer friend, I was finally able to work through your instructions and access the hall sensors.

The bottom line appears to be the rear HS has had it, it is clearly corroded on the end (similar to the one in your pictures) while the casing shows clear signs of cracking in more than one place. The front HS appears in good condition at present, but naturally I am going to order two and replace them both. Hopefully this will cure the current issue

I will post a couple of pictures of the HS shortly, they are showing as too large to attach at present.

 

[Big Bad Boris]

Here are the photos of the clearly knackered Hall Sensor.

 

[flybobbie]

Rust or crack first.

Some years ago bought some identical Hall sensors from Jap or French car, used same part, 2 for 15 quid scrap yard. Came with small cylinder.
On close inspection both were cracked but worked, not used on car though, not needed.
No rust.
Seems like the plastic shrinks and cracks.
Then rust takes hold and splits it further.

But why did yours get wet?

 

[Big Bad Boris]

Rust or crack first.

Some years ago bought some identical Hall sensors from Jap or French car, used same part, 2 for 15 quid scrap yard. Came with small cylinder.
On close inspection both were cracked but worked, not used on car though, not needed.
No rust.
Seems like the plastic shrinks and cracks.
Then rust takes hold and splits it further.

But why did yours get wet?

Good question. There is no sign of any water ingress in the boot area anywhere, it is certainly bone dry in the area of those hall sensors. It seems the sensors can simply degrade over time, they are now 12-13 years old in my particular car. Possibly they just absorb enough moisture from the atmosphere due to the lovely damp British weather. I would mind betting my ol’ buddy Silverstar won’t get similar problems in sunny Spain!

 

[RobbiZ4]

The HS contains a block of pure magnetic iron. It will get rusty by just breathing on it.

 

[flybobbie]

Doesn't help condensation in tail lights can only vent into boot.

Also air from cabin, vents over the boot rams in order to exit through the boot vents, so all cabin moisture will pass that way.

 

[Big Bad Boris]

An update. The hall sensors (E88 version) arrived from Germany during the week and I’ve just enlisted the help of a friend who’s a dab hand with a soldering iron to reattach the original plugs.

After some fiddling to get the HS’s back in place we were amazed to see that the roof worked perfectly first time.

It’s been up and down 6 or 7 times to make sure, but it is now seemingly working perfectly, might be my imagination but it actually seems quicker than before too.

Another massive thank you to Robbi, without his knowledge and brilliant guidance, pictures and instructions I would not even have attempted to fix this myself (with friends) :roll:

All in cost for the repair was around £29 for the 2 E88 HS delivered from Germany.

I am one happy camper

 

[RobbiZ4]

Rust or crack first.
[...]
Seems like the plastic shrinks and cracks.

Well, I'm pretty sure, that rust is the initial issue. Then the increasing size of the rusting magnet will crack the housing.
Same effect as with old concrete, where rust on the steel blasts the surfaces away.

 

[RobbiZ4]

...but it is now seemingly working perfectly,

1000's of congrats, well done!
It's been a very long journey from March until today. :driving:

Final question:
Did you replace the cutted zip tie with a new one around the ram and the plug of the rear hall sensor?