Another e85 roof issue 😵‍💫

[enuff_zed]

Is it worth disconnecting the battery 1st or OK to do live. Maybe disturbing them may help

Safer by disconnecting the battery of course, but then you won't know if that has changed anything. They shouldn't be powered until you operate the roof anyway, so I reckon if it were me I'd pull them both with the battery still on, check the plugs aren't corroded at all, then fit them back in the opposite positions to see if it makes any difference.

 

[10stb]

Safer by disconnecting the battery of course, but then you won't know if that has changed anything. They shouldn't be powered until you operate the roof anyway, so I reckon if it were me I'd pull them both with the battery still on, check the plugs aren't corroded at all, then fit them back in the opposite positions to see if it makes any difference.

Both looked really clean. No sign of corrosion. I've swapped them over and the roof is still working.

Will check it daily

Next time I'm at my inlaws place in Wighton I'll swing by and buy you a beer

 

[10stb]

Safer by disconnecting the battery of course, but then you won't know if that has changed anything. They shouldn't be powered until you operate the roof anyway, so I reckon if it were me I'd pull them both with the battery still on, check the plugs aren't corroded at all, then fit them back in the opposite positions to see if it makes any difference.

The s**t box is up to its old tricks again.

Haven't used it but would go out to the carport to start it and test the roof.

All good but forgot over Christmas and went to move it last week.....flat battery

Charged it up and had the exact symptoms as before. Roof no longer working, no lights on roof switch although both latching mechanism and motor would operate if connected directly up to a 12v supply.

My wife said "have you tried asking Gemini (AI on my phone).

I tried and seemed to be working through things methodically......until I took a step back and realised that I'd pretty much stripped out the car.

The carpets needed to come out as they were soaking.

Off side satellite air bag module had 2 brown wires hanging out of the connector.

Gemini suggested a k bus issue with the roof module being drowned out by a damaged line.(no lights showing and not working)

Should the k bus be reading 12v permanently or just when in ignition 2.

I found a 'slave' cable that bringing it down so have disconnected it. Not sure which module it goes to.

When stripping all the connectors from the k bus "comb", one was 12v, one was 9.6v and the rest 0v (this included the suspect one).

When I did a continuity test I was able to find the cable that goes from the the k bus to the console roof switch. I wasn't able to find the one to the roof module so not sure if there was a break in it......although the wiring diagram shows the roof module k bus wire coming from the instrument cluster.

Would value any thoughts.

Maybe I'll swap out those relays after all.

I was never confident that I'd fixed the issue in the 1st place 🫩

Thanks

 

[10stb]

Easier to access it guess

 

[enuff_zed]

Well given that all the modules communicate through the K-Bus, then you need to get that working right first of all. Only the centre airbag module is on the K-Bus though.
If the battery has gone flat, has it perhaps gone into Transport Mode?
Does the fan run on all speeds and the HRW work?

Could also be that the windows have lost their memory and need a reset. If the roof dsoesn't know where they are it won't work.

 

[bigwinn]

Still saying you have a loom issue

If it were me I’d connect a good loom in to prove/disprove

But I’d say that is the least of your worries with drowned airbag modules…

 

[enuff_zed]

I’d say that is the least of your worries with drowned airbag modules…

Agreed, I would now suggest you need to fix the airbag system first as that is the most expensive thing you have wrong.
I have spare modules and also some spare sections of loom with the plugs on that go to all three modules. Let me know if you need anything.

 

[10stb]

Well given that all the modules communicate through the K-Bus, then you need to get that working right first of all. Only the centre airbag module is on the K-Bus though.
If the battery has gone flat, has it perhaps gone into Transport Mode?
Does the fan run on all speeds and the HRW work?

Could also be that the windows have lost their memory and need a reset. If the roof dsoesn't know where they are it won't work.

The AI mentioned "transport mode" but this was discounted as the interior lights worked normally, as did the fan and the heated rear window switch would light up when pressed.

I did a window reset which went OK as the windows would drop a fraction to open and close. I also tried dropping the windows to try the roof. Also did the key in the door that operated the windows but not the roof.

The terminal on the nearside satellite sir bag sensor was pretty green so I cleaned it up.

I had planned to remove both sensors, dry them out thoroughly and use a good electrical contact cleaner on the connections. Do they just unbolt ?

I'm surprised that I had no airbag warning lights or fault codes considering 2 of the brown wires were out of the offside module.

I wanted to see if i could get life into the roof module by only having the 12v supply, roof switch and fly wire from the k bus comb (removing the other wires) to the roof module...but no difference

 

[enuff_zed]

I'm surprised that I had no airbag warning lights or fault codes considering 2 of the brown wires were out of the offside module.

Do you get the airbag light coming on when you first switch the ignition on? If not, then somebody has blanked it off.

 

[10stb]

Still saying you have a loom issue

If it were me I’d connect a good loom in to prove/disprove

But I’d say that is the least of your worries with drowned airbag modules…

Probably a good shout. Air bag modules weren't completely drowned....just the floor has a few mm of water.

My prefacelift z3 had nearly 2"

 

[bigwinn]

The AI mentioned "transport mode" but this was discounted as the interior lights worked normally, as did the fan and the heated rear window switch would light up when pressed.

I did a window reset which went OK as the windows would drop a fraction to open and close. I also tried dropping the windows to try the roof. Also did the key in the door that operated the windows but not the roof.

The terminal on the nearside satellite sir bag sensor was pretty green so I cleaned it up.

I had planned to remove both sensors, dry them out thoroughly and use a good electrical contact cleaner on the connections. Do they just unbolt ?

I'm surprised that I had no airbag warning lights or fault codes considering 2 of the brown wires were out of the offside module.

I wanted to see if i could get life into the roof module by only having the 12v supply, roof switch and fly wire from the k bus comb (removing the other wires) to the roof module...but no difference

Does the airbag warning light come on and off when ignition is turned on (not the seatbelt light!)

If not I’m willing to bet you’ll find some mk1 black insulating tape on the inside of your instrument cluster

 

[10stb]

Do you get the airbag light coming on when you first switch the ignition on? If not, then somebody has blanked it off.

Can't remember. I'll keep when I start putting things back together

I'll take your advice

Does the airbag warning light come on and off when ignition is turned on (not the seatbelt light!)

If not I’m willing to bet you’ll find some mk1 black insulating tape on the inside of your instrument cluster

I have the instrument cluster hanging out so I can check tomorrow

 

[10stb]

Do the satellite air bag modules just unbolt or are they attached to something in the sill

 

[enuff_zed]

Do the satellite air bag modules just unbolt or are they attached to something in the sill

Three 8mm nuts and lift them off the studs.

 

[10stb]

Three 8mm nuts and lift them off the studs.

Thanks mate. Will take them off tomorrow night and put them in the airing cupboard.

Will let you know ow how I get on with them.

Re..the k bus
Should it have 12v to it permanently or just when the ignition is on

 

[enuff_zed]

Thanks mate. Will take them off tomorrow night and put them in the airing cupboard.

Will let you know ow how I get on with them.

Re..the k bus
Should it have 12v to it permanently or just when the ignition is on

I 'think' only with ignition on. Can't find an adequate wiring diagram.
@bigwinn can you advise?

 

[10stb]

Hey guys

After @bigwinn and enuff_zed mentioned my air bag system yesterday I thought I'd take a look when I got home.

Nearside yellow one shows water damage on the outer casing and greening around the terminals.

Offside green one looks ok on the case and the terminals (although 2 of the brown wires had come out of the connector).

Centre console module is dry and shows no corrosion.

Is the alarm sensor supposed to be sat loosely on top of the air bag module?

I had a look to see if the air bag light comes on with the ignition but can't see anything. No taped up cables behind the instrument cluster either.

Interior is completely stripped out with gm5 module, relay carrier etc hanging so I have access to most areas.

Would you knowledgeable chaps give me a breakdown as to how the k bus works and what sensors are fed by it.

I have 12 wires on it. When I remove them all and test......1 has 12v, 1 has 10.3v and the rest are 0v (assumedly feeds to modules when connected up).

Should there be a 12v supply with the ignition off?

I'm guessing that the 12v one comes from the instrument cluster or the gm5 module with the 10.3 one being for whichever one the 12v one is not...if that makes sense

Clearly something funky happening with the 10.3v one although it was 9v yesterday. Maybe somethings drying out.

My plan is to do a continuity test on the k bus wires to check that they go 'cleanly' to their intended modules.

I connected just the 12v, the roof switch and a flying wire to the roof module from the k bus comb to see if I could get any life into the roof but nothing. No lights at the switch. Latching mechanism and roof motor both work when connected directly to a 12v supply.

I'd like to maybe have 1 little win

It's like bashing your head against the wall

 

[enuff_zed]

Well I reckon you'll be needing a new left module SBSL. Hopefully you can clean the plug to it ok.
Make sure you use Realoem to find one in a compatible batch to yours, not all will work.
Get me the part number and I may be able to help. (Or at least a photo of the label)

Over the top of the SIM85 module there should sit a black 'arch' piece. The MDD module screws to the underside of that.
You can see it there in your second picture. Just need two screws down through the arch and into the metal bracket.
The fact it is loose suggests someone has had that SIM85 out before.

It seems your airbag light has been blanked off due to problems someone couldn't fix!

At this stage, given the potential expense of fixing the airbag system, I would say concentrate on getting that sorted first before you worry too much about other stuff. The front cover between the instrument binnacles will peel off and you should then be able to remove whatever has been used to blank the light.
Get the looms, plugs and modules all sorted and re-establish a working airbag system. Until you do that you won't know whether it is that which is upsetting the K-Bus.

Get me photos of the three module labels and the plugs to each one. Hopefully I can dig out spares for all those and we can work on getting that sorted first.

I can understand your frustrations, but sometimes you really do need to step back, pick the most logical route and simply do one thing at a time!

Given the evidence of so much disturbance of the airbag modules, I would recommend you get them all back in and connected properly, then do a full system scan of them. Would not surprise me to find one or more have been replaced and not properly coded.

Can't recall where you are, but I wouldn't be averse to coming and helping with all that if needs be?

 

[enuff_zed]

@10stb - been looking further into the wiring diagrams. As far as I can see, each module has it's own power supply. They don't take power from the K-Bus, so in theory that should only carry a voltage with ignition on and the modules powered up?

 

[10stb]

Well I reckon you'll be needing a new left module SBSL. Hopefully you can clean the plug to it ok.
Make sure you use Realoem to find one in a compatible batch to yours, not all will work.
Get me the part number and I may be able to help. (Or at least a photo of the label)

Over the top of the SIM85 module there should sit a black 'arch' piece. The MDD module screws to the underside of that.
You can see it there in your second picture. Just need two screws down through the arch and into the metal bracket.
The fact it is loose suggests someone has had that SIM85 out before.

It seems your airbag light has been blanked off due to problems someone couldn't fix!

At this stage, given the potential expense of fixing the airbag system, I would say concentrate on getting that sorted first before you worry too much about other stuff. The front cover between the instrument binnacles will peel off and you should then be able to remove whatever has been used to blank the light.
Get the looms, plugs and modules all sorted and re-establish a working airbag system. Until you do that you won't know whether it is that which is upsetting the K-Bus.

Get me photos of the three module labels and the plugs to each one. Hopefully I can dig out spares for all those and we can work on getting that sorted first.

I can understand your frustrations, but sometimes you really do need to step back, pick the most logical route and simply do one thing at a time!

Given the evidence of so much disturbance of the airbag modules, I would recommend you get them all back in and connected properly, then do a full system scan of them. Would not surprise me to find one or more have been replaced and not properly coded.

Can't recall where you are, but I wouldn't be averse to coming and helping with all that if needs be?

Really kind of you but I'm miles from you. Bracknell im Berkshire. About 4 hours.

I owe you a beer when I'm next up at my inlaws holiday place in Wigton....from when you last helped me out. I've ordered a couple of roof relays (purple ones)....just because and just in case

Can the back of the satellite module be removed to check for inside corrosion and cleaned up if necessary.

The previous owner had it for 8 years and 5eally just used it as a weekender so not sure if it would have been him fiddling with tge warning lights