dennis_maine

I have a 2019 E450 4 Matic Wagon, USA Version. I'm changing the rear brake pads, which should be a 30 minute job. However, I never had a car with an electric parking brake before. I removed the caliper and the brake pads, and tried to push the piston back. When it wouldn't go back far enough, I remembered that you have to active the brake change mode in COMMAND. When I did this the piston was pushed all the way out of the caliper, which makes no sense, so I must have done something wrong. I put the piston back in and compressed it as far as it will go, which is not far enough. I thought I'd do the brake change thing in COMMAND again. Now it says the process was not completed successfully, and to push OK to retry or return to quit. By OK I assume they mean the touch pad, but pressing it does nothing. I went so far as to disconnect the battery, thinking it must be in some kind of loop or something. That didn't help. It's still saying press OK to retry. How do I get out of this mode?