Z4-forum.com

Hi all,

So I recently had this same issue pop up, and my roof not opening correctly (back window panel stuck when trying to lift and continues to bounce up and down). I got Carista out and diagnosed it as an A696 hall sensor faulty problem, and for the part to be about £215 to replace (part no. 54377224679). Ouch.

I took it to my local garage for them to diagnose (and replace the rear pads with EBC Redstuff which I'm finding to be excellent!) and they confirmed it was the 'hall sensor that sits on the piston' itself as I had diagnosed, confirming the £215 problem.

While following this thread, the above mention came up of the hall sensor from the 1 series convertible being an identical part and being only £15. (Part Number 54 34 7 190 735). For the cost difference I figured this was a no-brainer and thought it to be worth a shot if it works.

I can say that the 1 series convertible hall sensor is almost identical, but not quite, as it is missing the connector from one end. Having traipsed around the internet I have found the follow parts to be required if you want it to be a complete kit.



Hall sensor: £15 Part No. 54 34 7 190 735 bought directly from BMW (just pretend you have a 1 series convertible to get to checkout).
Connector pins: £2.50 Part No. 61131393723 I bought them from ebay but I'm sure you can get them from elsewhere.
Connector block: £3? Part No. 8373575-02 I personally reused the one that came off the old part, but one can be bought from aliexpress with a pretty long delivery time, however it means you can just do a straight swap when the part arrives.

After that you just need cut the wires to the correct length, strip the cable, crimp the connector pins to the cable, put the pins into the connector block, then put the part back into the car. It's fiddly, but I found it could be done in place without having to remove anything.

Beeacon.

There is nothing to go wrong in the hall sensor. Would be interesting if the old connector was cut off and reconnected back to the old wiring.
It flags up a fault because the connector becomes lose.

Test the sensor wire to 9v battery, in line with multimeter set to current and pass a metallic object over the face of the sensor, the current should change.

'There is nothing to go wrong in the hall sensor' I beg to differ! here is a picture of the sensor I removed from mine for the same problem, you can see the cover has cracked and water has got inside corroding the magnet and probably the electronics. In my case I reused the old connector with the new sensor thus (I think in my case at least) showing the problem was with the sensor and not the connector

An unusual occurrence as the inside is fully potted. How did water get on to it?
They do have a habit of cracking from the one's i have seen, like the epoxy inside expands.

Hi thanks for this info, I’ve bought a new e88 hall sensor for my e89 z4, however as shown in your photo the red and brown wires seem to be reversed on the new sensor (it also seems reversed compared to the yellow and brown leads on my e89 sensor) which way round did you wire it when you used the existing connector ie brown to brown. I ask as I have tested the new sensor and it seems you have to have the correct polarity.

I would be great full for any advice you may have before I attempt to change my sensor

Cheers

I connected brown to brown as I remember

Great thanks, I’ll have a look at the weekend

I'm closely watching this thread. Same issue here 2014 E89. Just bought it with this issue A696.

Thank you to those who noted the old part with work with some simple splicing.

I've run into the same issue (A696 open circuit), and according to Carista the error first appeared in December so no I've idea what caused the the failure as I wouldn't have opened the roof back then.

I've ordered the replacement parts (thanks Beeacon) and I'm planning on repairing this weekend, but a quick question for anyone that's already done this...

So far I think I've identified it's the sensor on the top of the boot piston that's broken, but I've only investigated with the roof completely closed. I haven't risked opening my roof since the fault appeared as I'm concerned I might not be able to close it again! In fact I don't even know if the roof/boot lid will even open if I try. So I'm wondering if it's possible for me to replace the hall sensor in this position, or is the access just too tight?

Cheers

The fault appeared on my z4 when opening and closing the roof. On opening the cycle stopped when the roof package went in the boot and the boot lid failed to close. On closing the roof failed the connect with the windscreen. In both circumstances the cycle could be completed by holding down the appropriate button ( on occasion a couple of presses were necessary). So pressing the dash button appeared to serve as an override.

I therefore replaced the top hall sensor with the boot open after stopping it mid cycle. Now everything is working as it should to my relief lol

Hope this helps

neallamb wrote: ↑Fri May 28, 2021 5:19 pm The fault appeared on my z4 when opening and closing the roof. On opening the cycle stopped when the roof package went in the boot and the boot lid failed to close. On closing the roof failed the connect with the windscreen. In both circumstances the cycle could be completed by holding down the appropriate button ( on occasion a couple of presses were necessary). So pressing the dash button appeared to serve as an override.

I therefore replaced the top hall sensor with the boot open after stopping it mid cycle. Now everything is working as it should to my relief lol

Hope this helps

Thanks it did help. I managed to get the new sensor fitted at the weekend, although I had to cut off the old connector and reuse that in the end (plus wait for a smaller sized crimping tool to arrive). Annoyingly it hasn't fixed my issue though so I'm a bit stumped!

I replaced the hall sensor with the longer lead on the top of the boot piston, and yet with both the old sensor and the new sensor I still get the same error "A696 open circuit, closing movement".
I tested the new sensor using a multimeter and it's working correctly, I also tried reversing the brown & red wires as they appeared to be opposite on the replacement, and if I disconnect the sensor I get a different error "A696 open circuit, closing movement, short circuit to negative".

So I guess the fault is on that cable somewhere, but probably out of my reach?

ClumUK wrote: ↑Mon Jun 07, 2021 10:28 pm I replaced the hall sensor with the longer lead on the top of the boot piston, and yet with both the old sensor and the new sensor I still get the same error "A696 open circuit, closing movement".

Did you notice, that there are 2 different hall sensors mounted underneath the ram?
The A696 fault is regarding the 2nd one with the red wire.

RobbiZ4 wrote: ↑Tue Jun 08, 2021 12:04 am

ClumUK wrote: ↑Mon Jun 07, 2021 10:28 pm I replaced the hall sensor with the longer lead on the top of the boot piston, and yet with both the old sensor and the new sensor I still get the same error "A696 open circuit, closing movement".

Did you notice, that there are 2 different hall sensors mounted underneath the ram?
The A696 fault is regarding the 2nd one with the red wire.

Hi Robbie, yes what confused me is that when I unplugged the shorter cabled sensor (red and brown wires) I got a different error code A691 which is why I thought it was the other one at fault (yellow and brown wires).
I did also try swapping the connector blocks and simulated replacing the bottom mounted sensor but the A696 error still remained.

Maybe I just need to replace both?

As it is reading an open circuit, it could be that it is not the sensor, but the cable that runs back to the control module in the boot (i.e. a break in the wire along the loom).

ClumUK wrote: ↑Tue Jun 08, 2021 9:11 am Maybe I just need to replace both?

Yes, you can.

But, if it's required, is not clear.

You can measure a bit with an ohmmeter:
~33k in one direction
~110k in the oposite direction, stepping down to 60k
These are the values of an dismounted part.