A bunch of random error codes??

[Deen435d]

Hi all,

I have a 2017 750Li xDrive. So recently my rear left (driver’s side) air suspension went. Drove it for about a week (it would inflate and deflate). Got that side replaced and no issues anymore.

However, since then, I’ve had a host of weird/random error messages when I’ve scanned my car.

They all seem to be electrical. My first thoughts is that the battery is on its way out (not sure when it was last changed), but wanted to get your opinions please. It drives absolutely fine and no errors show on the idrive besides the TMPS error (I think I need to get the sensors replaced). The only weird thing that happens now is that my headlights will flash randomly when driving on even with the ignition on.

I’ve owned the car for the past 10 months and haven’t had any of these issues come up previously when I’ve scanned before. Any thoughts please?


Many thanks!

[Raimo5]

Do all or most of those codes come back after you delete them?

[Deen435d]

Originally Posted by Raimo5

Do all or most of those codes come back after you delete them?

Sorry, yes I should have mentioned. About half of those codes stay on after erasing and the rest eventually come back after a quick drive

[Raimo5]

It does indeed seem like there is an issue with power stability. It could also be something with BDC as it has gateway integrated into it and can cause havoc on all data buses if there is an issue. BDC lives near microfilter housing and can get flooded if filter housing drain becomes clogged. Worth checking out to make sure that is not the case.

As the appearance of this issue coincides with latest visit to repair shop, then it is worth checking the area where work was done. Perhaps there is some visible data or power wiring damage. Also check battery terminals to make sure everything is tight there. Usually, G series is very precise in monitoring its battery performance and will make BatteryGuard call well before you would notice anything.

Software was not updated during your last workshop visit, right?

[Deen435d]

Originally Posted by Raimo5

It does indeed seem like there is an issue with power stability. It could also be something with BDC as it has gateway integrated into it and can cause havoc on all data buses if there is an issue.

As the appearance of this issue coincides with latest visit to repair shop, then it is worth checking the area where work was done. Perhaps there is some visible data or power wiring damage. Also check battery terminals to make sure everything is tight there. Usually, G series is very precise in monitoring its battery performance and will make BatteryGuard call well before you would notice anything.

Software was not updated during your last workshop visit, right?

Much appreciated for the in-depth reply. I literally watched the guys work through the suspension replacement so I know they didn’t snag or cut anything. Software wasn’t updated too. I’m also getting this weird headlight on/off situation during the daytime when the lights are on auto. Quick Google search showed it too could be battery related. And my TPMS system isn’t working - which another quick google search shows could be battery related (or the sensors need replacing).

Checked the battery with BimmerLink and it shows battery health is at 70%. I don’t think the battery has even been changed before.

I’m vying towards getting the battery changed initially and then investigating from there. Thoughts?

[Raimo5]

Originally Posted by Deen435d

Much appreciated for the in-depth reply. I literally watched the guys work through the suspension replacement so I know they didn’t snag or cut anything. Software wasn’t updated too. I’m also getting this weird headlight on/off situation during the daytime when the lights are on auto. Quick Google search showed it too could be battery related. And my TPMS system isn’t working - which another quick google search shows could be battery related (or the sensors need replacing).

Checked the battery with BimmerLink and it shows battery health is at 70%. I don’t think the battery has even been changed before.

I’m vying towards getting the battery changed initially and then investigating from there. Thoughts?

Does light switching only happen on auto setting and is stabile on other settings? What about if you forcefully turn it from end-to-end positions. Does it work more reliably after that? This light switching symptom is pretty common and it is caused by weak contacts in rotary selector. It is usually accompanied by light operating facility: rotary switch defective code, but that depends on software level. Old software does not have subroutines to detect it. Run the tests I described above to check for rotary witch functionality.

With failed wheel speed sensors, I would expect to see RDC transmitter initialization errors in DSC module. 99% cases it is just dead battery. Industry average is 7 years/100,000km for battery life. It is easy to check with wheel electronics programmers or ISTA.

Battery replacement would be a great start, but I kind of doubt it would be that. With battery issues, all trouble codes usually clear and then come back gradually. But if battery is old and suspected then replacing it would be a good starting point.

Also give BDC module and its connections a visual check to see if everything is order in there and there is no water ingression.