I worked on the car all day today. There is a ton of info online but I am now officially stumped and need the assistance of an Audi expert. Here are the symptoms and hopefully clues to a fix:
1) I went to start the car - ignition key turned and the steering is unlocked- and won't re-lock. No crank, and the steering lock is a new issue. The OBD scanner will power up, but can't connect to the car. Tried the hazard, lights, and brake pedal hold trick and unable to connect and clear codes. The car battery is new/ 13.5 volts
2) No dash lights in center portion of the display in front of the steering wheel - this is a common Audi problem so I replaced/soldered in a new relay and microswitches in the steering column module - tested repairs with ohm meter. No changes. I did not replace the motor - should I have?
3) I noticed the MMI is intermittently working, slow for the MMI to illuminate at times, and when MMI is on I can select radio stations but won't play.
4) MMI is always blank now - once in awhile a Audi symbol will flash for a few seconds on the screen. The only time the other dash lights are on is if the door is opened, or headlights switched on.
4) Lost power to glove box release, manually unlatched, but now works properly again. Was able to set parking brake, but not release parking brake.
4) I started eliminating modules with an optical loop bypass, and doing a 10 minute battery disconnect to reset. I only have one bypass loop and tried each individual module in the loop - no changes.
5) I checked all fuses in the engine bay, driver and passenger side fuse boxes - all test good. I swapped all the relays that I could if there were two of the same - no changes.

Random thoughts - are the MMI issues related to the steering column module or two completely separate issues? Do I need Vag-com or VCDS to clear fault codes and run optical loop test? Can I put an optical loop bypass in for each and all modules?! Do I leave each module unplugged when optical loop bypass is installed? Can I bypass each module, such as the gateway module? Is this just a bad relay or bad ground somewhere? Anywhere I should test for voltage in the fuse panel? Starter solenoid signal wire? And lastly, could this just be the MMI control panel in center console?

Any advice and input is greatly appreciated! I feel like the root problem will be simple stupid.

 

For the issue with nothing communicating, wake up the CAN module, I believe the process is to turn on the emergency flashers, hold the brake pedal, and hold the headlight stick back to force the brights on. While holding all of that tomfoolery on, connect to the J518 module, if you have VCDS that will be the "Access/Start Authorization Module" I believe it's ID 04. Check for codes, you're probably locked out due to false theft detection. Clear it and everything will wake up. Are you able to solder or willing to learn basic thru-hole part soldering? You can fix the J518 module with about 20 bucks in parts from Mouser/Digikey (plus the lock motor if you really want to replace that, you can get them on eBay/Amazon/etc, they are quite generic but they rarely fail) and charge the customer some decent labor for R&R of the module and an hour plus for soldering the parts on.

For the MMI, if you are in total lockout, it won't come on. If it still has issues, are you sure you checked optical bypass on every single module? The #1 and #2 causes for MMI inop on C6 are the bluetooth module, and the bose amplifier, in that order. The bluetooth module is under the drivers seat (actually slightly in front, under carpet, as long as you don't have lumberjack hands you can just pull the corner of the carpet up, weasel the plastic box out, and remove the module with the seat in) and it gets flooded when the cowl drains plug, usually happens in winter when the crap plugging the drain up gets ice in it. You can replace the bluetooth module without any coding, it is plug and play. For the bose amp, primary cause of failure on those is on the avants, the rear washer hose breaks and leaks. If you don't have an avant, the bose amp is probably fine.

What OBD scanner are you using? If it's a generic one you may not even have access to the J518 module.

 

Avantly, thank you for the helpful information. I think my issue now is simply not having a scanner that will communicate when doing the wake up procedure. I'm have tried a Lemur Bluetooth Bluedriver, Ancel VD500 and a Innova 5610 scanner. All will power up, but will not communicate with the car. My next step is to purchase VCDS with HEX-V2 from Ross-Tech. https://store.ross-tech.com/shop/cat/vcds/ic/

Fingers crossed that I can get the car to communicate to clear the fault codes. Am I on the right path?

 

You are on the right path. If you service any VAG vehicles even semi-regularly, the Ross Tech tool is one of the best investments you can make. As an added bonus, if you buy the genuine tool, you get access to the forums and once your forum account is verified as a genuine user you will find that there are a ton of very experienced and helpful guys on that forum who can help with all sorts of coding and electrical diagnosis issues. There are a ton of coding options on your car that allow you to easily change the personality/behavior/etc and once you learn the VCDS interface it is quick and simple to change all of these settings.

 

The Ross-tech Hex-v2 Scanner arrived and I downloaded the software on the laptop. Plugged into the car and did the brights/flashers and brake wakeup procedure and was able to clear the codes. The car fired right up and all is well. Thank you for the help!!!

 

Berminator, if that worked, then you need to at a minimum replace the micro switches and relay in your J518 module. You'll need a cheesy soldering iron, some solder and solder wick, the highest strength isopropyl alcohol you can find at walmart, and the 3 micro switches, 2 micro switch levers and relay. You can find the part numbers in other threads I've posted in regarding this subject. The switches, relays and levers should cost you about 20 bucks plus shipping. You'll need a dremel tool or vice grips and patience to get the J518 module off the steering column. Once you fix it with quality parts you shouldn't have to touch it again. If you need any help or suggestions regarding the repair just PM me or post in this thread. If you can't find the switches or relay in stock use findchips, octopart, or ebay.

 

I am moderately capable with tools. I have seen one approach to your J518 module which is to clip the wire for the steering lock and your more ambitious program. Any thought on the difference in outcomes? I do not need to be stranded in this car but it spends a fair amount of time driving to remote areas for bicycle rides.

Thanks

 

My experience is that with new switches and relay, there should be no problems for the forseeable future. I've also replaced the lock motors in about half of the modules I've done, but I've never actually seen the motor fail. It's always the switches or the relay (and even the relay, I am unsure of, they all seemed OK but I didn't put them through any durability testing). The switches wear out and end up triggering the theft lockout, it thinks the column lock has been forced.

For soldering, there is a product called "chipquik", there is a generic brand which is sold on Amazon for a good price. This stuff is a solder type alloy with an extremely low melting point. If you want to make the job super easy from a soldering standpoint, you can use this stuff. You use solder wick to remove the bulk of the exposed solder (I prefer Quick Braid's Easy Braid product, any braid will do just make sure the braid has flux in it, flux-free braid is a pain in the ***). Then you put some chipquik flux on and alloy in this low temperature stuff. Once you alloy all the pins on the relay, if you're quick enough you can actually melt all the joints with the iron and they will stay melted long enough to remove it. The switches are easier than the relay. Then you just clean up the holes with the solder wick, then clean with some iso alcohol, solder on the new parts, and once again clean with some iso.

For cleaning, I use the little horse hair flux brushes you can get at hardware stores that sell plumbing supplies, I cut the brush to somewhere between 1/4 and 1/2 its original length so that it is stiffer and this allows you to brush any areas where flux has hardened. I finish with Q tips, I like the wooden shaft medical type Q tips but any will do. Always use the purest iso alcohol you can get, I think you can get 90%+ at the department store, I use the 99.9% stuff that I buy by the gallon.

As far as snipping the wire, I have never used that approach but have read about it. I think you may need to snip it while the column is unlocked. In general I am not a fan of that approach because now there is no longer a steering lock, I know from a safety risk stanpoint it's probably not a big deal unless you live in some crazy hilly place but I always try to do the "OEM style" repair.

If you are wondering what type of soldering iron, it just depends on whether you want to spend $20 on something that will get the job done, or closer to $75-100 for a lower end temperature controlled soldering station that will be useful for other soldering projects. For tip cleaning while soldering, no need to buy anything special, you can cut a little square out of a household sponge, wet it and put it in some small container like the cut-off bottom of a plastic water bottle, and as you are soldering you can just wipe the tip on that sponge to clean it up nicely.

For solder that you use to install the new parts, these boards were probably lead free even though they were made in the mid 2000's but 60/40 lead solder will work fine as well, and will be easier to work with and more reliable (though these particular solder joints don't have problems with failing whether or not you use lead free).

My oldest repair for the J518 module was around 2016-2017, a model year 2005 or 2006 C6 A6 and that car is still driving problem free today. I used the part numbers referenced in my other posts, and I did not replace the lock motor on that car. I believe it is up to around 250k miles now and the failure was around 125k miles. You can remove the security screws with a strong pair of small vice grips that have nice sharp jaws, but it is kind of a pain. Deepening the slot in the screw with a rotary tool makes the screw removal easier, however you have to put something down on the carpet to keep the metal filings out, and I wear a full face mask with a hoodie with the straps tied tight over my head and the perimeter of the mask because that job is a particularly excellent way to cover your head with metal filings. I really like my eyeballs the way they are.

 

I hav ordered everything but the motor from Mouser last night. I have a small iron that should be fine and will get some Quick Braid.

Thanks