Does anyone have the wiring diagram for the parking brake and mmi?
My mmi goes out and a parking brake fault go on at the same time I want to see what they have in common.
I had that problem about 2 months ago. Have you spilled any liquids around there where the buttons are? It’s a slight irritation, but you’re gonna have to pull the center console out. Pull the MMI unit and pull the parking brake lever. The lever is bad. Buy a cheap ebay one for like $20. I did. That’s literally all that is wrong with your parking brake. It’s that lever. As for the MMI, it runs on a fiber optic loop. If there is a bad module or a broken optic cable, it will shut down. BUT! Since you mentioned the parking brake, most likely I believe you spilled something. If you did, and it was soda or coffee, then one of your MMI buttons may be sticking. If two buttons are pushing at the same time, it will shut down. This is why I suggested pulling it. Take it apart and clean the buttons real good. I ended up taking my motherboard out, throwing all the buttons and all in the dishwasher and getting another MMI motherboard. If you don’t want to take the MMI button console thing apart, you can try to pour alcohol down into the buttons. But make sure the car is off and MMI is off. Alcohol is good because it dissolves sticky stuff and evaporates quickly. And it won’t corrode electrical contacts. Do not use water! Anyway, just my .2 cents. I had both go out at the same time. That was my issue. If you do all of that and the MMI still cuts out, you probably have a bad module somewhere. Check the trunk, left side. Those modules all hook into the MOST loop. So does the Bluetooth module but that’s in the passenger side floor area somewhere. Best way to check what module is bad, get a MOST loop bypass harness. They are cheap. eBay has for $10. Even dealer has them. Disconnect one module and plug the bypass harness into the optic cable(not module). If MMI stays on, then that module you unhooked was bad. But keep going until you find the bad module. If you find a bad module and don’t need that module(Sirius XM radio, for example), then just leave the bypass loop in and enjoy. If it’s the amplifier, then you might wanna get it fixed. You won’t have sound until you do if you bypass that.
Thanks I did fix it I ran the ring brake diag and found a bad bluetooth module.
The parking brake warning was a loose connection on the battery terminal block.