Hall Sensor Replacement - Done

[TBDL]

Post of appreciation for those that provide guides etc. I was having issues with my roof stopping when I open and close it. I looked up the symptoms on here, and other places; a dodgy Hall Sensor seemed the most likely cause.

30 minutes job, new sensor fitted, roof working like a charm once more.

I used the One Series Hall Sensor, cut off the connector from the old sensor, soldered it onto the new sensor and clipped it in, cable tied the cables in place.

Part numbers and prices for comparison, so £176.43 saved by simply soldering on the old connector to a One Series sensor:
54 34 7 190 735 £14.30 One Series Hall Sensor
54 37 7 224 679 £190.74 Z4 Hall Sensor

Images in case it helps others identify the sensor and location, as finding it was pretty much my only challenge with this job:

 

[roadvoyager]

This would be useful in the "e89 How to" section.

 

[flybobbie]

What was wrong.
Looking at corrosion on parts was it damp that broke the Hall sensor?

My cars problem that area was the connector, on your car it has green paint on it. My car had blue.
The connector came loose because it had no locking barb.
I just super glued and cable tied it.

No problem since some several (scary) years ago.

 

[TBDL]

This would be useful in the "e89 How to" section.

There is a big write-up there by someone long before me, so I added my photos as a comment on it in case this helps anyone.

What was wrong.
Looking at corrosion on parts was it damp that broke the Hall sensor?

My cars problem that area was the connector, on your car it has green paint on it. My car had blue.
The connector came loose because it had no locking barb.
I just super glued and cable tied it.

No problem since some several (scary) years ago.

Honestly, I cannot tell what the issue was. The old HS is the one pictured on the worktop and it’s visually fine, it was in place perfectly too (I dislodged it ahead of the photos). Replacing it did the trick though.

Today I got a Creator C410 scan tool as I needed to reset an airbag light on my X3, so I scanned the Z4 for good measure and sure enough the code that had been thrown was A696 Hall Sensor.

 

[flybobbie]

But that open circuit might just have been connector loose as on my car.
My car roof stopped after roof was in boot, boot open.

It was only a burst of inspiration that led me to reach down and jiggle wires and roof could be returned closed.
I realised a problem down there.
Sure enough it was that bad connector with the paint on.

I think BMW realised it was a problem, i think the replacement has a longer lead to the control box.
I think it was just convenient for them to assemble all in one go and fit a small lead ready for fitment.
Who knows.

 

[TBDL]

But that open circuit might just have been connector loose as on my car.
My car roof stopped after roof was in boot, boot open.

It was only a burst of inspiration that led me to reach down and jiggle wires and roof could be returned closed.
I realised a problem down there.
Sure enough it was that bad connector with the paint on.

I think BMW realised it was a problem, i think the replacement has a longer lead to the control box.
I think it was just convenient for them to assemble all in one go and fit a small lead ready for fitment.
Who knows.

Could well have been just a loose connector, I guess, but I did not do anything other than remove the HS, solder the connector onto the new HS, fit it back in. I did not jiggle the wires, move any other connectors etc. I will pop the roof up/down a few times now I have the code reader and see if it comes back at all, but for now it is operating as it should once more - so for £14.30 and a dot of solder I'm happy!