E60 M5 weird DSC issue

[TheAngryDog]

I have a very odd issue with my E60 M5. A few weeks back the battery was disconnected for a few hours while the fuel pumps were replaced. After reconnecting the battery and going for a drive, I noticed that dsc was staying engaged, despite me having it set up in the idrive to be MDM mode with M button pressed. To be clear, the DSC light is OFF, and I cannot disengage it.

Pressing the M button doesn't change the DSC status (EDC is changed), pressing the dsc button doesn't do anything either.

We have reflashed the dsc module, reset it, readjusted dsc, reset the steering angle sensor, defaulted the dsc as well but still got the issue.

It doesn't matter what iDrive is set to (MDM, off), pressing the dsc button or the M button, nothing happens.

EDC works fine.

In ISTA, when pressing the dsc button it wasn't registering anything.

Does anyone have any ideas as this is boxing my head in.

I thought it may be a battery issue so I have replaced and registered a new battery to no avail.

Why did i think it was a battery issue? Well oddly, on Saturday I ran several fault checks while my car was running and then when I was ready to set off driving. MDM mode engaged and then disappeared about 30 seconds later.

I had a 70 minute drive and when I arrived at home, I pulled onto the driveway and MDM engaged, but this time it stayed engaged. I could turn it on and off and disable DSC.

I went for another drive around the block without turning the car off, and all was well.

Turned the car off and then back on and it was all still working.

I then locked the car and left it for a bit and then came back to it and i could no longer engage MDM or disengage DSC.

So this led me to a battery issue. But today, changing the battery made no difference.

I've ruled out the buttons, we have been able to reflash the DSC module, but could it be that the module got damaged when the battery was initially reconnected?

I'm very much at a loss now. Pulling up to my driveway did something (it's a slight incline), but what I don't know.

I have zero codes relating to the DSC. The only codes I have are for the fuel level sensors, which for some reason have decided to not work after refitting the filter on Saturday.

Does anyone have any suggestions?? No matter how stupid it may sound? It's driving me mad.

Thanks.

[TheAngryDog]

I still have this issue. Oddly DSC has turned itself off a few times randomly and then gone back to being stuck on.

[matty13]

Hi

Have you checked the passenger side footwell carpets after some rain for damp. There are a lot of electrics under there and the drains block easy.
Also maybe worth checking to see if any of your brakes callipers are seized or binding.
Good luck i had an e60 m5 for a couple of years and they are fantastic cars

[TheAngryDog]

Thanks for your reply.

I haven't checked the carpet, but I will. I did check the drains near the ECU and they are nice and clear. I've even removed the drain flaps as I know these can sometimes be a hinderance.

[A44RON]

check out Mtech Guy's channel on YouTube - he did a video on his E60 M5 DSC issue a few weeks back and resolved it. He's a genius M car mechanic and his vids are awesome

Hope this helps