BDT: Audi B8 S4 Mechatronic Unit Fixed with VCDS 

Totally normal. Every 3.0t engine does this. Especially after and oil change it will do it badly.

Chain tensioners need to be replaced when it rattles for like over 4-5 sec

Same here, did you ever get it fixed permanently?

@@warrenzonator I did yea so I took it to 2 garage and lost my rag as both said you need a new mech unit. But I know for a fact it’s not the whole mech unit. As adaptions fix my issue all be it temporarily.. and the most common fix and advise to give anyone.. it’s buy the mech unit repair kit which is actually a lot for techs back when these were under warranty. Replace all the bits or just the solenoid . But also order from a reputable place a 2nd solenoid as these 501 box’s use one for the clutch pressure and another for the gearbox pressure. Other gearbox pressure is the one that causes repeat offenders! Every 200 miles. It’s about £30 and if you’ve already had the mech unit out just drop the oil replace that other solenoid and bosh your fixed ! Was so annoyed after spending about 4-5k trying to fix it and ended up fixing it myself when I researched the gearbox parts for about it £60 .

@@martsrs so you had the mech unit replaced but the problems came back, and it ended up being the gearbox solenoid?

Just trying to help you guys! I love what I do!

@Eggbert823 I also went through the process of elimination with what process worked the best. Thanks for the comment, I'm just glad I can help the community.

Bad mech bad trans

@@boostdynamictuning that's not good, I don't have any error codes through, car drives perfectly fine

Please watch the video. It shows what I used.

Yes

Vcds wins everytime People never say the hand facts but obd11 lacks correct measurement value. For example boost pressure is wrong sometimes. Also it won't perform some adaption. VCDS hands down wins everytime

I can definitely tune the atw engine but I’ve seen so many issues with the car due to lack of maintenance that I’ve stopped tuning it.

Yes for sure, not all of them. If I recall the last two adaption the forks move.

Thank you! Glad you enjoyed the video

@@boostdynamictuning did the adaptation and that solved my issue! Thanks for the information on what might be the issue and a possible solution. One of the issues I had was while in park and with the parking brake on, if I revved the engine, I could feel the car trying to launch forward. Adaptation took care of the issue. The one thing I would have added to your video is that you must perform the adaptation while the car is running. Took me two tries to figure that out. It may seem obvious, but there are things you do without the car running but turned on. Newbie error on my part. Thanks again!

@@mrappstate not a problem! Glad we could help! You're right though

Saginaw michigan

Dang man :( Sadly mech unit Stop driving it and replace adapt before the clutches get destroyed. Not trying to scare you, just trying to save you from buying a whole new transmission

@@boostdynamictuning do you know what website you would recommend to buy it from ?

@@jhonyflores56 dealership only I don't trust any other sources

No, it needs to be done in the same day. It's a fairly quick process.

Restart vcds and unplug cable Try again.

@@boostdynamictuning it still does it afterwards, thanks for your response.

@Dan did it say this immediately after pressing start or basic settings? If so then the conditions are not right. For example ypu have fault codes Other example is transmission tempeture isn't up to temp.

@@boostdynamictuning after I click on “Go!”, it starts and shows “running” then after about 20 seconds or so, it aborts due to safety reasons, ATF temp is between 40-50c when I checked live data. Also no codes relating to transmission or any other powertrain codes for that matter. There was one at one point that hasn’t come back since I cleared it, “P150C RPM request from transmission cannot be performed” in the ECU. This probably happened when a transmission line blew and it didn’t shift, had to get it to a parking lot about a mile later and towed it, replaced line and oil and wanted to do the adaptions like you have in the vid. Didn’t run it long after it blew an oil line. The code probably came from this, but no codes popping up right now. It still drives now and shifts with the occasional jerk when coming to a stop

Definitely something wrong. The mech unit is bad if it's showing these symptoms after an adaption sadly.

@@boostdynamictuning Does the problem completely go away after doing the adaptation or does it creep back in again? If it does creep back how long does it take?

Yes, I believe I stated this in the video.

Sadly, no. They have different transmissions.

It's possibly but most likely mech unit time :( I have a video on replacing one as well. Not to hard for a novice.

It looks easy but seems like everyone replaces them and it doesnt fix it. Taking it to a shop first. Could trying this cause damage? I kinda wanna give this a try just to see if it would fix it

@@Lowkeystee Did you get this fixed?

​@@boostdynamictuning do you have a link for the mechatronic unit

@@abdulhanif7247 I went straight to an Audi dealership, and bought it from the parts department.

Michigan :) Hbu?

In located in New York is there anything you guys can help me with my problem

@@rokimarinaj9442 hey did they helped u I got the same problem now

Did this myself and works fine for approx 200 miles the. Just reverts to the same! Deffo mech unit failing :(

@@boostdynamictuning where in Michigan are you located

Yes you can :)

@@boostdynamictuning awesome! Thanks bro. Appreciate the s4 test pipe video too! Got mine done in a few short hours.

Try this and if it doesn’t help your mech unit is probably starting to fail.

You can control it but I do offer setting crackles to your liking.

Are you performing the calibration in the proper temperature range? 45-50c.

@@boostdynamictuning ATF temp was reading 41*C when I started. I tried each calibration twice before I gave up on them. ATF temperature when I gave up was 59*C. I’ve searched around and found others who have had a similar issue, but there was no follow up to a solution.

@@Jason-tz8xn did you try doing adaption again at proper temp? If it fails it usually means dsg isn’t in proper spec usually meaning you’re dsg is on its way out. Do the adaption again at 40c and report back.

@@boostdynamictuning Ok. I will try again. My mech feels pretty good. It was a little jerky on upshift from 3 to 4 and a little on downshift from 3 to 2. A little bit of a release forward from 2 to 1 in auto or dynamic, but only if I’m easy on the brakes. The up and downshifting is smoother after the kiss point and distance sensor calibrations. I will try again and report back. Thanks.

Did you found a solution? Mine says aborted- safety reasons too :(

Hate to say it, but mech unit is bad

@@boostdynamictuning I have the same thing, also “Gear selector 2 engaging process not successful”, gets stuck in 2nd every once in a while stopping especially on hills but turning it off and on again fixes it. Could a wiring harness replacement/repair kit fix it or would I need to do solenoids too, maybe even whole unit?

@@Ben-wf8rlI would replace the whole mechunit with a new one from Audi. It comes with a harness.