Firstly, a quick note of thanks to Robbie and others on here who helped me diagnose and fix a problem hall sensor that was causing my Z4 E89 roof to fault. After a couple of months of faultless operation, I now have an intermittent roof problem as follows:
- On opening, the rear screen roof panel folds over the top roof panel and then the operation stops. It stops the moment before the boot lid is going to open.
I get a bong and a red light.
No fault codes are generated as indicated by subsequent scans of the ECUs.
If I wait a minute or so and press the roof button again, the boot opens and the whole operation completes normally.
Subsequent immediate repeated cycling of the roof normally works fine.
This is my thinking so far:
- No fault code generated means it is unlikely to be a hall sensor – so microswitch?
The intermittent nature of the fault and its timing (usually the first operation of the day) suggests a sticking switch?
The consistent position of the roof when it stops would indicate to someone who understands the sequence of operation of the sensors and switches which switch or pair of switches it would be?
I believe there are 8 microswitches and, for no particularly good reason, I thought it might be switches 2 and/or 3 in this diagram?
The parts are available at my local BMW service department for around £26 each, so not too bad, with equivalents on eBay being about £10 more.
Can anyone here increase my chances of replacing the correct switch(es) to minimise my investment in time and money – or even tell me it is not a microswitch problem at all?
Thanks
here, and many thanks.
, but before I embark on the fix/f*ck up of a lifetime, what do you think of the idea of the application of a small amount of WD40 to each switch in situ, to try and relieve the stickiness? Any likelihood of that working, or is it more likely to put the switch out of action completely and forever? 
