Loads of errors just appeared

Jeverson28

Member
 Somerset
Hi everyone! I recently changed my steering wheel and noticed after reconnecting the battery the boot light stopped working. The car drove fine otherwise though.

I thought it might have been a fuse so I swapped fuses 77 with another 10A fuse to see if it was that. it wasn't so I put them both back to their original position.

Just went to start the car and it won't start and I get all these errors. Anyone have any ideas what I've done? And ideally how to fix it?
 

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You need to clear all the faults with a code reader…then re apply power and reread with fault code reader..

Many of the ECUs probably s**t themselves with the battery disconnection..

Check battery is fully charged..before re-reading codes

Then report back..
 
Any advice for code readers? I don't have one! I'll charge my battery overnight.

The weird thing is the car started fine after reconnecting the battery. It was only after I tested my fuses this happened!
 
The weird thing is the car started fine after reconnecting the battery. It was only after I tested my fuses this happened!
No doubt whatever that fuse powered has caused the errors because there was still power to other modules, you could try disconnecting the battery again for half an hour and then reconnecting and seeing if all is then good
 
No doubt whatever that fuse powered has caused the errors because there was still power to other modules, you could try disconnecting the battery again for half an hour and then reconnecting and seeing if all is then good
Just tried this but no luck unfortunately :(
 
try checking the big Fuse 30 that you didnt disturb that.......big black relay looking thing with a diagonal bar on it
 
Any advice for code readers? I don't have one! I'll charge my battery overnight.

The weird thing is the car started fine after reconnecting the battery. It was only after I tested my fuses this happened!
So Foxwell and others do dedicated versions, Bimmergeeks Protool is the best app based one.

You MAY have fried the FRM..common on change of battery state / coding and sometimes just on start up.

Without a BMW specific code reader you're pissing in the dark
 
Just a thought but could you have a fault with the boot light and you have now blown the fuse that you tried and then replaced, do you have any new fuses to try?
I don't have any to spare but I've ordered a big kit of 60pcs - will arrive tomorrow. I'll replace both 10A fuses that have been touched.

try checking the big Fuse 30 that you didnt disturb that.......big black relay looking thing with a diagonal bar on it
I'll take a look at this at lunch at get back to you.

So Foxwell and others do dedicated versions, Bimmergeeks Protool is the best app based one.

You MAY have fried the FRM..common on change of battery state / coding and sometimes just on start up.

Without a BMW specific code reader you're pissing in the dark
Are there any other symptoms associated with this? I've no idea what it is but that sounds expensive! Thanks for the advice on code readers, I'll take a look.
 
I don't have any to spare but I've ordered a big kit of 60pcs - will arrive tomorrow. I'll replace both 10A fuses that have been touched.


I'll take a look at this at lunch at get back to you.


Are there any other symptoms associated with this? I've no idea what it is but that sounds expensive! Thanks for the advice on code readers, I'll take a look.
E90 based cars FRMs will all fail at some point..

An eprom on board gets corrupted and the FRM falls on its face.

Wide range of possible symptons depending what corrupts..

Lights not coming on , lights not going off , lights flashing, other sub systems not working due to FRM shitting on the data bus.. etc etc

Caused by FRM powering up as normal, battery changes / unplug.. coding etc etc

Good news is its easily fixed till next time..but.. requires removing FRM and sending to a man on a bench with special coding tools and jumper cables...around £50 in the UK ish

It is alledged that a later reprogramming of the unit to a higher revision level can fix this..but I've not yet seen any concrete proof of the fact!
 
So I have a happy and somewhat embarrassing update to this!

Managed to get the car started and running fine over lunch. The steps I took were:
  • Charged battery overnight.
  • Tried starting car (no luck).
  • Disconnected battery and waited 15 minutes.
  • Pulled down fuse box
  • Made sure the big fuse with the diagonal line on it was properly pushed in (it was, I think)
  • Examined the fuses and noticed I accidentally moved fuse 4 into fuse 5 position yesterday.
  • Moved it back where it's supposed to be.
  • Reconnected battery.
  • Started the car.
Turns out, the position of the fuses matters. Who knew? 🤦‍♂️
 
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