I am looking for some help and advice please, as what started as a fairly straightforward repair is turning into a COSTLY NIGHTMARE for my E90. :(
I put my 2005 E90 in for some investigation as the radiator cooling fan was spinning up and down (staying spun-up for only a few seconds), intermittently trying to cool the radiator.
The garage I took it to aren't a BMW dealer but they are ex-dealer techs and have been great over the years.
They tested the car and all seemed ok but they found errors on the diagnostic with the cooling system, so reset them and sent me on my way saying if the fault re-occurs then come back.
The issue re-occurred and a few days later and I started to get engine temp alerts on the iDrive display and then a battery alarm when I parked up at home.
I got the car back to them next morning. On the drive over, the iDrive date and time were blank (showing menu screen though) but radio wouldn't work etc.
They had a look and said that they needed to replace the water pump and would have a look at the iDrive and battery etc.
They replaced the water pump and then checked the battery etc. When investigating they found a pool of oil in the rear left well below the kit in there (sat nav, controls, cd autochanger etc) but said that it didn't appear to have gotten into anything. They took all of the electrics out and then cleaned it up, put all the kit back in.
During testing of the water pump later other alarms started going off on the iDrive and the wipers were coming on by themselves etc.
They put back on the diagnostic and were seeing communication errors on the fibre in the car (they said that they were seeing them from the first diag as well).
They then tried to locate the failure and carried out a control update to ALL of the control units. One didn't update and therefore it pointed to that being the problem.
This unit was in the steering column and controlled things like the active steering, the iDrive, the wipers etc so they said I needed a new one.
As active steering is involved no one in the UK had the right unit (and apparently it has to be coded to the car) so they sourced one from BMW Germany via the local dealer. (costly :( )
They then fitted it and then started to see other alarms. It seems that the DSC/ABS control unit in the engine bay was sending too much voltage to the unit in the steering column, which suggests that was the proximate cause of the issue and that is what burned out / broke the steering column control unit.
Therefore, I am faced with what they said was a further £900 + VAT for a new DSC/ABS unit (apparently it comes in two parts, the electrical and mechanical) or they said they could send it away for repair for approx. £200. I jumpted at that and they sent it off.
The unit part number is 34526770679 and though the repairer couldn't find it on their system they said they would take a look.
I am now 3 weeks in with nearly £1500 bill so far and the repairer say that they cannot fully test that control unit (due to it being rare etc) so they cannot find a fault and cannot fix it.
They said that they could, however, sell me a recon part (which is actually the elec and mech parts together) for £800 + VAT.
I only want the elec part (£900+VAT from BMW) but costs are spiralling, I have been without a car for 3 weeks and I am no longer sure what to do.
Does anyone have any advice on which I should go for?
Or even better, know where I can get a recon elect part of 34526770679? (tried but no one seems to recognise it)
Or know someone who could repair this unit for me?
I would REALLY appreciate any help and thoughts etc.