Roof fault A696 Hall sensor

neallamb said:
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
Click to expand...

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! :cry:

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 said:
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".
Click to expand...

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 said:
ClumUK said:
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".
Click to expand...

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.
Click to expand...

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 said:
Maybe I just need to replace both?
Click to expand...
Yes, you can. :D

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.
 
RobbiZ4 said:
ClumUK said:
Maybe I just need to replace both?
Click to expand...
Yes, you can. :D

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.
Click to expand...

Well yes I'd rather not have to replace both :lol:

Just for my sanity this is what I'm seeing:

- Permanent fault on reader, and "Roof movement impaired" when pressing dash button with red flashing light:
A696 Hall sensor, open circuit, closing movement, rear-end module, Fault currently present, Fault currently not present
- I replaced with new the 1st hall sensor mounted at top of boot piston, long cable, yellow & brown wires, white connector. Still get the same error code & message as above:
A696 Hall sensor, open circuit, closing movement, rear-end module, Fault currently present, Fault currently not present
- If I disconnect the 1st sensor I get different message, but still referring to A696:
A696 Hall sensor, open circuit, closing movement, rear-end module, Short circuit to negative
- If I disconnect the 2nd hall sensor mounted at bottom of boot piston, short cable, red & brown wires, black connector. Instead I get different code:
A691 Hall sensor, rear-end module open, Short circuit to negative
- Plugged the old sensor into the 2nd hall sensor black connector block. No change, only get the same A696 error as before:
A696 Hall sensor, open circuit, closing movement, rear-end module, Fault currently present, Fault currently not present

Do you think this likely to be a faulty sensor, or rather a broken wire somewhere else in the harness?
 
If you disconnect the sensor & get a short circuit to negative script, it sounds like a cable fault rather than a component fault.
Rob
 
ClumUK said:
Do you think this likely to be a faulty sensor, or rather a broken wire somewhere else in the harness?
Click to expand...

Thanks for all the details.
From my experience, there should not be any wiring problem between the plugs of these 2 HS and the CTM plug. This is a very short connection with separated wires apart of the roof loom.

I will think about it tomorrow...
 
Have a look at the following picture to get a better understanding:

20201015_test3.jpg

I've done some tests with these hall sensors (HS) on my desk. The LEFT side of the ram directs to the front of the car (the description in red on the
picture is wrong!).

On the right coupling lock, there are 2 hall sensors mounted, each of the same type. The original mounted ones differ in it's wire colour as well as in the lenght of their wires. Spare parts will always be of the same part number as well as the wiring colour and lenght.

The left HS2 (assigned fault code A696) is repsonsible for the 1 second stop of the boot lid while closing, short before it reaches it's closed position.

The right HS1 (assigned fault code A691) is repsonsible to detect the open position of the boot lid.
 
Important link to correct fault code descriptions:

https://bmwfault.codes/

FaultCodeTranslator.jpg


You have to select the line with the correct ECU variant!
 
Initial state:
ClumUK said:
- Permanent fault on reader, and "Roof movement impaired" when pressing dash button with red flashing light:
A696 Hall sensor, open circuit, closing movement, rear-end module, Fault currently present, Fault currently not present
Click to expand...
=> "HS-2"

ClumUK said:
- I replaced with new the 1st hall sensor mounted at top of boot piston, long cable, yellow & brown wires, white connector. Still get the same error code & message as above:
A696 Hall sensor, open circuit, closing movement, rear-end module, Fault currently present, Fault currently not present
Click to expand...
I assume, you've replaced "my HS-1" with a new one from stock?
Then this message is correct, as the initial fault code directs to the 2nd hall sensor.

Disconnecting a single hall sensor doesn't make any sense, as you add another fault. Only replacing a HS with a new or working one does help.

Can you provide a sharp(!) picture of the top of your original hallsensors, like the following one?
20200516_sm.jpg

The red marked area is important.
 
Hi Robbie, thanks for all the detailed info! Yes you were right, I had replaced HS1 at first. Instead I replaced HS2 and then all was fixed :)

I had confused myself with my diagnosis of the error codes, just annoyed now as I cut off the old connector needlessly.
You can see in the picture the issue was probably caused by a cracked casing:

20210615_212302.jpg
 
I bought two sensors and cylinder from local scrap yard, they were used on some Japanese or French car.
Close inspection revealed one had cracked.
I found i could test with battery and multimeter, the current changes through them on detection.
The cracked one worked fine.
I broke it open and inside is epoxy encapsulated sensor and magnet.
Must be this epoxy expanding and causing them to crack.
 
flybobbie said:
I found i could test with battery and multimeter, the current changes through them on detection.
Click to expand...
As described earlier, it's much easier to test even mounted on the car:
RobbiZ4 said:
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 unplugged part.
Click to expand...
 
Hi guys,

Sorry to flog an old thread but it seems the best place for this without going through all the rigmarole of starting a new thread and clogging the forum with multiple thread of the same issue.

Aquired my Z4 last summer from my dad who’s had it since it was 2 years old.

I’ve got the dreaded A696 code, I was wondering if anyone could shed light on which ram this sensor is located. Is it the ram for the clamshell/boot lid, or is it the ram that lifts the roof assembly out of the boot?

In addition I have a A692 for rear module closure microswitch. Is this the switch in the boot in the plastic bracket that the boot lid closes onto with the rubber bung?

This has happened after I had the car garages over most of the winter, so I’m assuming the issue with the sensors cracking due to the epoxy swelling must have something to do with either age, temperature, or a combination of both?

Again sorry for flogging a dead thread, appreciate any help

Ben
 
Shrinkage on the wires causing breakage i have now seen on the wires to the brake fluid level switch.
Just where the wires enter the switch the insulation has shrunk and broke exposing the wire inside.
 
Yes in the roof too.

All my roof problems broken wires. The insulation seems to shrink and break.
Then eventually the unsupported wire inside breaks.
Reason why roof moves so far and stops or random bongs with roof closed.
All on the right side as there are more wires to go wrong and bundled tighter together.
I got fed up with them breaking, so only thing to hand was 13amp flex, i used the wires from that to fix.

Just need to go through forum to find fixes.
 
Thanks Bobby,

I’m going to have a look when I get a chance probably this weekend, I’ll post my findings, appreciate the reply

Ben
 
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