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2004 BMW Z4 2.2 - De-snagging


SiC

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The PDF only describes how to set up SP Daten as far as I can tell. I got the full set of steps, updated by myself to clarify a bit where needed, to setup a used airbag module which absolutely possible as I've done it on my E65. As you mentioned, you flash the module (overwrite to latest factory programming for your car), write the VIN to it and then set the system time.
I think the E65 modules and setup are the same for the E85 as many of them can be retrofitted between each other. Definitely going to need to pick your brain on it if you've done it before!

I'm going to pull the module first to find the failure cause. I.e. if soaking wet or corroded its probably the drains and I need to clear/fix them to fix the root cause before replacing the module. I'm kinda hoping giving it a clean with IPA might bring it back to life however it seems the water usually shorts them internally and buggers them. Even then, it probably needs the system timer resetting if it's not been talking to the rest of the system for a while.

Main thing first too is getting hold of the software. I'll order a decent reviewed cable from Amazon as my blue kkl cable is a bit shite and I wouldn't trust it for flashing modules.
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It's a fantastic car that was a flipping bargain. Nothing major wrong, just common Z4 faults because of BMW bollocks.

On VAG you'd just swap over a second hand airbag module and it'd be good to go. Or worse case 30 seconds copying the coding across. But that's because I'm very familiar with how VAG deal with modules and so I know exactly what I'm doing. 

Squeaky brakes are probably me ragging the shit out of it near home to get a proper feel for the car. Probably fine now it's cooled off a bit. 😁

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I've just bought this cable as it's only £25 after promo codes. 

https://amzn.eu/d/2A9sRIm

Didn't see a need of paying for the £40+ ones as likely all the same circuit and should be a proper FT232 at that price. But as it's Amazon, it'll be easy to send back if pants. 

Heater fan resistor is NLA. I can't see any aftermarket ones either. However reading around it seems they almost never fail. It appears usually it's the climate control panel that fails. Tbh that would make more sense as I wouldn't expect the fan resistor to fail so that it only run on full when 50% or more and then cut in/out. Actually better to be that panel too as can be had for ~£35 second hand and massively easier to fit than delving into the depths of the dash for a fan resistor. Unfortunately I don't think it's one easy to diagnose (at least without wiring diagrams and INPA) and will likely be a parts dart exercise. 

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Went to a local cars and coffee this morning. Some extremely nice tin on show - I'll put some photos up later. 

Anyway I glanced at that rear left.

PXL_20240413_100830268.jpg.c11d1ef36eb9e275e28785223e39c1de.jpg

Err yeah I've smoked that. Other side has a reasonable chunk of pads left on it. Absolutely baking hot that side but cool the other.

I can't get a caliper today from GSF, Euros or my local parts place. So I bought some cheap pads and I'll give the caliper piston/sliders a clean up and hope I can get away with it.

Cheapest pads I could buy too. Discs will stay on for now as even though they have obviously got very hot, there is a lot of meat left on them. I'll have a check for warpage but I don't think they're bad going on that it's not an intermittent scrape. Hopefully I haven't quite fully had metal to metal yet. 

PXL_20240413_122559533.jpg.e605f3963c00ea3cd122d2fae0ffd39b.jpg

 

If a clean up and new pads doesn't work then I'll have to get in a new caliper. I don't think they're expensive for an eBay special. GSF didn't have any even listed unfortunately. 

 

Hopefully I can get it sorted today so I can at least use it in this nice weather. Steering is 100% okay too. So must be when the rack gets hot on a long drive. Not checked the tyre pressures yet - just driven the thing. 

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18 hours ago, SiC said:

Had a quick Google. It's a fully electric power steering rack. Apparently it's two gears or something that goes sticky. They get worse if you have the cabin hot. So explains why I've probably had it as I've had the heating on max the whole way. 

Yep, mine does the sticky steering thing as well, seems to be a common thing as they age.  I've been reading up on it and it sounds like it's one of those things that should be a 5-minute fix but actually takes half a day because BMW made everything completely inaccessible.

Only the Z4Ms have hydraulic steering and thus escape the issue, but they're slightly* more expensive.

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Just now, wuvvum said:

My wipers don't quite park at the bottom either.  When you switch them off they go to the bottom of their travel and then come fractionally back up before stopping - don't know if yours is doing the same?

Yeah they do that. The wipe is actually to the correct amount to the right of the windscreen and not too far. The park seems quite approximate and depends on windspeed. They're as variable as my BL stuff. 🤣

I suspect the wiper mechanism maybe worn. If so I'll keep an eye out for a cheap second hand but tbh it might stay like it. They wipe the windscreen perfectly fine after all. Or maybe the park switch can be adjusted. 

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This'll do. Hopefully 🤞 

If it's the hedgehog then I'm going to need to contact breakers directly. Realoem shows one exists but I'm not 100%. Pelican parts guide on replacing this panel says almost always this panel that is the problem and not the hedgehog on the E85.

Screenshot_20240413-185613.png

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16 minutes ago, Supernaut said:

Meanwhile the rear calipers on my E36 are alright, but I replaced the fronts because they kept sticking!

Have a look at RTG Group on eBay for brake stuff.

I was about to ask what is recommended on eBay. 

There weirdly seems to be more and more parts NLA on these Z4. That fan resistor is NLA and even I've found cruise control stalks (E85 specific) are now NLA. They used to be £100 for genuine but scalpers have bought up the last stock and want £250+ for them. 

I'm surprised at how much is not available given the popularity of these cars. Ime with VAG, possibly because of so much commonality, you can get parts easily for much older models than say this. For example the Golf MK4 has loads of aftermarket and genuine bits still available. 

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To get to the left satellite B Pillar module, everyone online says you need to remove the seat and a whole load of plastic trim. Being a savage I figured most of that was unnecessary. Turns out I was correct.

The foam is wet but not sodden. 

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Tbh this is probably less risky as much less brittle plastic to break.

This is a satellite module. Basically it appears there are multiple airbag modules (why BMW??) that are connected together optically and on CAN. Not sure if this fires an airbag as the usual special yellow airbag connector (the one that shorts the pins when disconnected) only has the optical feed but no detonator connected to it. 

PXL_20240413_161745835.jpg.06562b205f31da05f99701a2faa4e811.jpg

Anyway inside looks fine. Connector is dirty though.

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I tried cleaning the connector but it's still not playing ball. 

The other airbag modules say it can't see this left module. 

PXL_20240413_152548944.jpg.4d6ba1e9ff69ad3a192e3b205e35b26b.jpg

PXL_20240413_152534475.jpg.41fdb7eff7a13bb664142b107dd6c4ae.jpg

PXL_20240413_152551487.jpg.b0410a60f03ee0d34c069a40e7467340.jpg

 

If I try connecting directly to the Left Satellite module, it can't connect to it. Auto detection doesn't see it either.

PXL_20240413_164009540.jpg.571f3ddd2e25f0ed5af9f1e62ecaa389.jpg

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So it looks like this module may well be dead. But why? Inside looks fine. Presumably it speaks over CAN as well as optical. So that optical transceiver should be fine.

My fear is the loom connector is damaged. I might try sticking the right satellite module (which I know works) into that left side and see what happens. Presumably it won't do stupid stuff but should hopefully tell me communication is okay on that loom connector if it can be seen on the main car network. 

I also need to find a known working replacement of this module. Need to have a gander on RealOEM and see if any other later ones are compatible too. 

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44 minutes ago, SiC said:

I was about to ask what is recommended on eBay. 

There weirdly seems to be more and more parts NLA on these Z4. That fan resistor is NLA and even I've found cruise control stalks (E85 specific) are now NLA. They used to be £100 for genuine but scalpers have bought up the last stock and want £250+ for them. 

I'm surprised at how much is not available given the popularity of these cars. Ime with VAG, possibly because of so much commonality, you can get parts easily for much older models than say this. For example the Golf MK4 has loads of aftermarket and genuine bits still available. 

I always go to my local dealer (bowkers) for anything non mechanical. Been doing it for 3 old BMs now. Everything is available next day and prices are surprisingly fair. BMWs parts back for their old models is superb in my experience.

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How do you know it the satellite module speaks over CAN? My rear seat satellite wasn't showing up at all when scanning for all modules despite receiving power etc. The fibre optics cable must have had a crack somewhere, causing the "blinking" messages to never arrive/be sent out, basically making the module invisible to the larger system. You can easily check the fibre optics cable by shining a light into one end (probably where it connects to the parent airbag module under the dash) and see if it shines through the other end. Mine wouldn't at all.

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Just now, Schaefft said:

How do you know it the satellite module speaks over CAN? My rear seat satellite wasn't showing up at all when scanning for all modules despite receiving power etc. The fibre optics cable must have had a crack somewhere, causing the "blinking" messages to never arrive/be sent out, basically making the module invisible to the larger system. You can easily check the fibre optics cable by shining a light into one end (probably where it connects to the parent airbag module under the dash) and see if it shines through the other end. Mine wouldn't at all.

I don't know for certain as I don't have any wiring diagrams and only an assumption based on the Scantool should be able to see it. It could be also that the main airbag controller acts as a gateway for diagnostics so it doesn't need to be on any CAN to feed back. 

I forgot to mention on my post that the red light was shining out of the end of the cable with the ignition on, so at least the fibre-optic feed is good. I did wonder if the modules LED emitter has failed too. 

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19 minutes ago, Schaefft said:

How do you know it the satellite module speaks over CAN? My rear seat satellite wasn't showing up at all when scanning for all modules despite receiving power etc. The fibre optics cable must have had a crack somewhere, causing the "blinking" messages to never arrive/be sent out, basically making the module invisible to the larger system. You can easily check the fibre optics cable by shining a light into one end (probably where it connects to the parent airbag module under the dash) and see if it shines through the other end. Mine wouldn't at all.

Just found this: (it's not HTTPS so might be a bit of a pain to download in some browsers)

http://www.unofficialbmw.com/images/09 E85 Adv Safety Electronics.pdf

You're right. There is no direct connection to the diagnostics network with these satellite modules. It's all done over the fibre-optic network (byte flight) with the Safety and information module (SIM) acting as a gateway. 

Which means that if the SIM can't see it, going by the codes on my scantool above, it disables communication functionality. 

I'd love to have a wiring diagram for that satellite module connector so I can see if it's at least getting power. 

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8 minutes ago, SiC said:

Just found this: (it's not HTTPS so might be a bit of a pain to download in some browsers)

http://www.unofficialbmw.com/images/09 E85 Adv Safety Electronics.pdf

You're right. There is no direct connection to the diagnostics network with these satellite modules. It's all done over the fibre-optic network (byte flight) with the Safety and information module (SIM) acting as a gateway. 

Which means that if the SIM can't see it, going by the codes on my scantool above, it disables communication functionality. 

I'd love to have a wiring diagram for that satellite module connector so I can see if it's at least getting power. 

Ista+ will tell you, unfortunately I don't have it myself, I got the wiring diagram from a BMW specialist who I hoped would diagnose my airbag problem (didn't but gave me enough info to continue and figure it out myself).

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Fun* fact. The rear calipers on this are the same as the E46 and Rover 75/MG-ZT. Not sure why GSF don't stock them.

I'm debating whether to be a skinflint by just replacing the one or just do both and be done with it. If I'm bleeding brakes after caliper replacement, I am bit tempted to do both. Don't want to do one and then have the other go soon after. 

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5 minutes ago, SiC said:

Fun* fact. The rear calipers on this are the same as the E46 and Rover 75/MG-ZT. Not sure why GSF don't stock them.

I'm debating whether to be a skinflint by just replacing the one or just do both and be done with it. If I'm bleeding brakes after caliper replacement, I am bit tempted to do both. Don't want to do one and then have the other go soon after. 

If the other caliper is a bit tight to push back then it's probably worth replacing the pair but if you just try pushing it back and the piston easily retracts with minimal effort then I would say save your money and just do the one

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1 minute ago, RoverFolkUs said:

If the other caliper is a bit tight to push back then it's probably worth replacing the pair but if you just try pushing it back and the piston easily retracts with minimal effort then I would say save your money and just do the one

I'd like to get this back on the road quickly though and keep it on there. I don't have the luxury of trade parts supplier getting stuff to me same day, so whatever I buy will take 2 to 3 days until the mail order part comes. That's one of the bigger factors in my mind. 

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Regarding the steering, it's quite likely to be a stiff joint in the intermediate shaft 

image.png.46373ae9a53584204f5bdf05f6af2357.png

It's not often disastrous but it could get gradually worse to the point you'll want to sort it. The only way you can really diagnose it is by disconnecting it from the car and exercising the UJs in as many directions as possible, I've known them to seemingly operate freely but bind up at very certain angles. In normal operation this may not be noticeable but could cause an irritating, intermittent tight spot 

On cars designed with the rack at the front of the engine, the intermediate shaft is typically routed perfectly* across the hot engine to connect the end of the column from the bulkhead to the pinion shaft on the rack in front of the engine.. which naturally overheats the joints and causes uneven thermal expansion to a certain extent which over the course of thousands of miles knackers the joint and causes it to bind up. 

It's happened to me on a 15 plate Audi, previous week it was in for MOT and the steering was absolutely fine, next week it's back because it's almost undriveable, sure enough one of the UJs on the intermediate shaft had bound up. So it had gone from nothing to undriveable in the space of a week. In other cases it will be a "TADTS" and may never get any worse! 

F series BMWs have an adjustable preload bush on the rack, it's common for the bush to wear out and cause a rattle, but the cap doesn't have a stop so it is possible to tighten the cap above the spring slightly too much which will give an odd steering sensation and tight spots. 

I'm not sure if the E series has a similar setup, I've only ever heard of and experienced that issue on the F series but if these have a similar setup then it could be worth checking 

image.png.5d00db1415c579c5f279437af81285f1.png

I'm sure you can visualise what's going on in that above picture, the piston shaped "thing" slots over the rack, then a spring is placed on top, then the screw cap goes on top. This is totally adjustable with plenty of room for error!

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9 minutes ago, SiC said:

Yeah these: https://www.ebay.co.uk/itm/154750665374

Or individual on the same part for £29 each. 

That's rather cheap so it's probably worth just doing the pair in that case. 

I have dealt with that seller before a couple of years ago, it wasn't the best experience to be honest, the item arrived late, and was of shockingly poor quality, and was missing parts. It took them just over a week to just send out a missing union that should have been in the kit..

It was a power steering pipe set and pump for my old Focus. It was about £100 for a brand new set from them, bearing in mind it would have cost about £200 for a pump and £150 for the pipes from a more established seller, so there was a hefty saving involved.

The pipes were not usable in the condition they were sent in, I managed to modify them to make them work but most people would understandably have not buggered about with them because at the end of the day they weren't fit for purpose. The power steering pump was extremely noisy. It all just about worked, but no idea how long for as I sold the car a few months after that. 

So the parts were of poor quality, but they worked! You could say I got what I paid for :)

I'd never want to fit parts from them to someone else's car because I'd want to be confident they were going to last, but I just wanted to share my experience to help you make your own mind up 🙂

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1 minute ago, SiC said:

Bigger problem I'm having at the moment is finding a replacement airbag module. Plenty of right but not left. 

Give Bridgend recycling a shout, I'm sure I've had a few bits off them before and they seem to keep everything you could possibly want for a BMW

Bridgend Recycling (BMW Spares)
01233 713447
https://g.co/kgs/uq1DsTA

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