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I have a 2016 Q5. I tried to upgrade my Nav system with CarPlay so I bought one of the add-on kits that gives a you a box and wiring harness to plug into the back of the head unit. It was working good but I kept tinkering with it and when I tried to get the Head unit back in it seemed obstructed probably from the extra room taken by the CarPlay box and wiring harness. My mistake was I started trying to force it a little and then:
- The MMI display went blank/black. It is not backlit at all. As if it gets no power. - The MMI control buttons on the console (ie. Media, Navigation Menu, Radio, Back, etc..) do not backlight nor do they seem to operate - The Head unit lights for Parking Assist, and Auto Off and Traction Control DO WORK and are backlit - The DVD player will not accept a DVD - The A/C and heat controls are lit and seem to be working fine.
The things I've tried are:
- Ive removed the CarPlay unit altogether but now the OEM is not responding so I assume I have damage something in the OEM equipment
- I've checked and replaced fuses on the passenger side and in the rear. - I did a loop test on the unit behind the glove box and on the amplifier in the back. Those were the only modules I could find. - I figured I must have fried the head unit so I purchased another one used off of Ebay but after plugging it in I got the same thing. - As a last resort I detached the battery cable to see if something would reset. It didn't.
- I am not a mechanic but I happen to have a Ross Tech VCDS so I ran a diagnostic. As expected I got errors but honestly I don't know what else to try. I will attach a report of the scan. I also did an optical scan and it said it could not communicate with radio of instrument cluster. Here is a link to the report:
- Ive disconnected and reconnected all wiring to the head unit and have inspected wires and pins and cannot find an issue
I just can't afford to spend a bunch to repair it right now (out of work for now) so I would really appreciate any help for something I could try. About to hit the road for a road trip anniversary with the wife and its gonna stink to not have a radio.
Wow!
That might be the most faults I've ever seen. Sorry.
So many say "unknown error code"...and there are tons that say "No Signal/Communication".
It certainly seems like you have either jacked up the wiring or shorted something out (eek!)
Did you clear all codes and these are the ones that returned?
If not I'd start by clearing the old codes with the old unit or maybe even perhaps without the unit altogether, since you suspect you may have damaged it, and see what returns.
The new ebay unit will probably require component protection to be removed if you ever want to get that to work (dealer only afaik).
Also as an FYI some electrical components have what's called "component protection" on them when buying them used. It's a sort of dealer security lock that prohibits people using what might be stolen parts. The used one you bought might have that and would not allow you to properly test it til the dealer removes the protection (and no you can't do it yourself via Vagcom). Also because of the extensive list of errors, you might have messed something up with the actual wiring harness which could be a rats nest to try to figure out. All I can think of is get a multimeter and start testing to make sure all the wires in the plug are getting a signal of some sort.
Try removing and re-seating the 2 CAN -bus connectors (A) at the fuse panels on both sides of the dash. You need to slide the leaver up to remove the connector, don't break them as they are specific to a VIN #. It is very easy to remove if you take your time.
Also you want to join the Ross-Tech forum at Ross-Tech.com, post your same post from here along with the scan file. There are a lot of sharp people that read that forum, including the Ross-Tech owner and his staff.
07-23-2020, 07:21 PM
I screwed up my MMI
