Brake Service Mode
Thread Starter
Senior Member
Joined: Feb 2025
Posts: 265
Likes: 89
From: Seattle
Currently ‘2015 S550 4matic. Previously 03 E320, ‘06 S430, ‘08 S550 4matic
Brake Service Mode
Hi Folks
I am set to replace the rear pads on my ‘15 S550 today. However, I’m not able to get to the maintenance mode setting.
I have key on in 1st position, in trip mode, push the top phone button on right spoke and OK button on left spoke simultaneously but nothing happens. No drop down menu to select maintenance mode. Any ideas?
Also, If the electronic parking brake is off is that the same as maintenance mode?
Will I I be able to retract the caliper piston without damaging something?
Any ideas?
Thanks
Chuck
I am set to replace the rear pads on my ‘15 S550 today. However, I’m not able to get to the maintenance mode setting.
I have key on in 1st position, in trip mode, push the top phone button on right spoke and OK button on left spoke simultaneously but nothing happens. No drop down menu to select maintenance mode. Any ideas?
Also, If the electronic parking brake is off is that the same as maintenance mode?
Will I I be able to retract the caliper piston without damaging something?
Any ideas?
Thanks
Chuck
Last edited by SSBN629 Seattle; Feb 14, 2026 at 12:42 PM.
Super Member
Joined: Jun 2025
Posts: 784
Likes: 249
From: USA
To access maintenance mode on your ‘15 S550, ensure the vehicle is in "ON" (not just the first position) and try holding the phone and OK buttons longer. If that doesn't work, try disconnecting the battery for a few minutes and reconnecting it, as it can sometimes reset the system.The electronic parking brake being off is not the same as maintenance mode. You still need maintenance mode to retract the caliper pistons safely. If you can’t get into maintenance mode, using a scan tool that supports caliper retraction is a good alternative to avoid damaging anything. Good luck with your brake pad replacement.
Thread Starter
Senior Member
Joined: Feb 2025
Posts: 265
Likes: 89
From: Seattle
Currently ‘2015 S550 4matic. Previously 03 E320, ‘06 S430, ‘08 S550 4matic
To access maintenance mode on your ‘15 S550, ensure the vehicle is in "ON" (not just the first position) and try holding the phone and OK buttons longer. If that doesn't work, try disconnecting the battery for a few minutes and reconnecting it, as it can sometimes reset the system.The electronic parking brake being off is not the same as maintenance mode. You still need maintenance mode to retract the caliper pistons safely. If you can’t get into maintenance mode, using a scan tool that supports caliper retraction is a good alternative to avoid damaging anything. Good luck with your brake pad replacement.
Carlos in Seattle helped me as well. Turns out I was on the wrong Trip mode screen. Once I got to the total mileage screen, the maintenance mode was available.
i’m off and running!
Take care
Chuck
Super Member
Joined: Jun 2025
Posts: 784
Likes: 249
From: USA
Glad to hear you figured it out! It's easy to get mixed up in those settings. If you have any more questions or need help down the road, just let me know. Safe drivin.
Thread Starter
Senior Member
Joined: Feb 2025
Posts: 265
Likes: 89
From: Seattle
Currently ‘2015 S550 4matic. Previously 03 E320, ‘06 S430, ‘08 S550 4matic
