[OldenburgerM3]

You might get into trouble requiring a dealership visit if you don't put the car into brake maintenance mode before touching the rear pads!!

I just learned a lot. Lots of people have run into problems, and the answers are spread through several brake threads so here's a summary of what I learned and we can work on this collection:

I swapped brake pads for a track weekend to Bluestuff. I come from an E92 with experience on rear electric parking brake from an F25 X3. In order to get the rear caliper pistons to retract whilst doing the job I removed the motors and turned the actuator manually. Reassembled everything and went to the track no problem.

Days later when I swapped the pads back to the OEM pads the car freaked out when I turned it on after completion as described above. It's been mentioned several times on the forum, but I got:
-brake system malfunction
-chassis stabilization malfunction
-reduced driver assistance

A test drive around the neighborhood confirmed things weren't right: No brake boost and no braking rear left or front right. A reset via battery disconnect didn't work.

Apparently the problem is that the electric parking brake motors and the actuator position aren't lining up with the system calibration. So I went with the "TurboJG-Method" (https://g80.bimmerpost.com/forums/sh....php?t=2076632) with TopJimmy's suggestions to see if I could re-align roughly to the initial calibration.

Proper sequence for rear brake pad work, as we know it:
Parking brake NOT set
Put the car into service mode
Do the brakes (https://g80.bimmerpost.com/forums/sh....php?t=1955832)
Take the car out of service mode.
You can now test the parking brake and hopefully drive the car normally.

If you already screwed up and are reading this because of the error codes try the TurboJG/TopJimmy fix, it worked for me:
In the car set the EPB switch to off. Do not enter brake-maintenance-mode.
Reset/delete all fault codes with your app.
Disconnect battery.
Unbolt the parking brake actuators x2 and use a Torx 45 bit with your fingers to tighten the center bolt until the pad grabs the disc. Should be very little turning, turn the other way if you were wrong at first (clockwise I think).
Unscrew the bolt until it lets go of the disc, a quarter turn did it for me.
Reassemble, then connect battery.
Go in car and set the parking brake switch to on.
The EPB should engage and be fine.
Start the car and hope all is well and stays well.

More notes:
Diagnostic mode: start/stop button three times (I was unable to clear any codes with BimmerLink unless I was in this mode. Could be coincidence but I never know what mode this keyless car is in anymore without a clear ON and OFF)
Parking Brake maintenance mode: BimmerLink app, "enable" will wind the actuators back fully so the piston can be compressed to fit pads, "disable" again when you're done. This occasionally fails, but make sure you know what the state is and try again until you have a good answer. Listen to the parking brake motors.

What is still unclear to me is the exact procedure about WHEN exactly to pump the brake pedal to get the pads to the rotor after a brake job (car on or off? maintenance mode? battery disconnected? does it matter?). What got me into trouble initially is that in order to start the car you have to push the brakes, which needed pumping. So I pumped and potentially confused the car more than TurboJG did but I admit I didn't do the job right to begin with not wanting to mess with the brake maintenance mode.

I will edit this post with anybody else's suggestions as we go.

[djpeetur]

I use ista to put it service mode and out of service mode. I still had parking malfunction. But after 2 months it went away. So maybe time will help after you take it out of service mode.

[freshxdough]

If you use the special tool to rotate the actual brake piston back you will have no issue with brake malfunctions. Disconnecting motors and winding back from the outer portion can cause issues as the actuator is disconnected. If the car is awake faults will be set.

As stated above, use special tool to wind the back. Replace pads. Reset indicator. Press brakes to snug to rotors and drive away with no issues. Brake service mode is not absolutely required, it’s an alternative for using special tool

[GBDiaz13]

Haven't received my car yet, but I am preparing myself for the brake change. Gonna be using bimmerlink. I'm reading on some other threads and see people mentioning pumping the brakes before starting the car and activating the ebrake again.

Got the new pads, cables for the OBDII, and bimmerlink downloaded, but no car lol.

[vasillalov]

I recently replaced my pads front and rear on my G80 because they were completely worn out after track day at road America. The rears had just 1mm left of pad material. I used a caliper reset tool from Autozone to reset the rear caliper pistons. The tool turns and pushes the piston. No problems at all.

[stbm5]

did rear pads today, used BimmerLink and it worked flawlessly. steps i did:
turned off everything in car
put phone into airplane mode
inserted OBDLinkMx
connect phone to OBDLink via bluetooth
opened BimmerLink and connected to OBDLink
went to parking break then clicked service mode, could hear the EPB wind back
removed calipers (FYI you need a 17mm wrench that is fairly thin, i tried a couple that didnt fit but ultimately found one that did but only if i didnt put it fully on the caliper nut)
removed brake wear sensor without breaking it (probably the most difficult thing)
i did not loosen any cables but set brake on paint can
used caliper compression tool, you dont need to compress much, less than half a turn
replaced pads
put calipers back on
went back to BimmerLink, had to reconnect but when i did i took it out of service mode and it worked the first time
then went to Error Memory on Bimmerlink and cleared some errors but i didnt see any that were related to brakes
then i backed out of BimmerLink and disconnected.
restarted car, pumped brake pedal then set the parking brake
then cycled car off/on, no lights/alerts/codes
did a quick drive and all functioned as it should.
complete time for brake pad replacement was about 30min

[Autoaddict]

So is this now an issue for DIY’era at home for the rear brakes? I thought once you put the rear calipers in service mode, you just go ahead and change the pads, then remove out of service mode and then that’s it. Is there more to it then that?

[stbm5]

Originally Posted by Autoaddict

So is this now an issue for DIY’era at home for the rear brakes? I thought once you put the rear calipers in service mode, you just go ahead and change the pads, then remove out of service mode and then that’s it. Is there more to it then that?

its basically that simple but you still need to remove the caliper and you still need to use a caliper compression tool. you still need to make sure you dont damage the brake wear sensor. the time and effort savings is you dont have to remove the electric parking brake. using BimmerLink only retracts the EPB, still need to retract the caliper pads but with appropriate tool it takes 3 min per side. you can also rent said tool at autozone or spend 60 bucks and buy one. all said it takes about 30min to replace both pads, thats not bad.