Intermittent Problems with C450 Sport+ Mode
Super Member
Joined: Nov 2015
Posts: 721
Likes: 74
From: NYC
2016 c450 / 2016 VW Jetta 1.8t / 2006 Wrangler X
Super Member
Joined: Nov 2015
Posts: 721
Likes: 74
From: NYC
2016 c450 / 2016 VW Jetta 1.8t / 2006 Wrangler X
MBWorld Fanatic!
Joined: May 2008
Posts: 7,653
Likes: 560
2016 C300
It's telling that the car is losing the crackle on its own irrespective of any mechanical intervention. While I don't believe the ECU has any adaptive capacity to learn how you drive and adjust itself, the tranny does. Since the over-run is triggered in part by a hard downshift, it's possible the TCU is inadvertently changing its shifting behavior in a way that prevents the over run from having any effect.
Might be worth doing a TCU reset to see if it helps:
Procedure Reset Transmission Adaptive Learning DIY
Turn the key to position 2. You should see all the dash lights come on. ...
Press the gas pedal all the way. ...
Wait. ...
Turn key to OFF, position 0. ...
Release the gas pedal.
Wait 2 minutes. ...
Start the car and drive.
Might be worth doing a TCU reset to see if it helps:
Procedure Reset Transmission Adaptive Learning DIY
Turn the key to position 2. You should see all the dash lights come on. ...
Press the gas pedal all the way. ...
Wait. ...
Turn key to OFF, position 0. ...
Release the gas pedal.
Wait 2 minutes. ...
Start the car and drive.
Super Member
Joined: Nov 2015
Posts: 721
Likes: 74
From: NYC
2016 c450 / 2016 VW Jetta 1.8t / 2006 Wrangler X
I tried that twice yesterday. No change. The first time I held the pedal down for 5 seconds before switching off and recessing. The second time I held down for 10 seconds. No difference in sound or feel.
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Super Member
Joined: Jun 2015
Posts: 630
Likes: 188
C450, GLS 63 and a few other things
Anyone try just disconnecting the battery for a while and see if anything resets? Have no idea if it will actually work, but this seems to be something that is changing over time...
Super Member
Joined: May 2014
Posts: 613
Likes: 42
From: NYC
2014 C300
With my W204 I take it out on the backroads or to the hawk's nest and I'll reset my TCU before I do a few runs and by the time I'm through and turn the car off and back on you can feel a massive difference.
Newbie
Joined: Mar 2016
Posts: 8
Likes: 0
C450 AMG
Just wanted to mention I've been having the same problem recently too. It's intermittent, but in Sport+ while driving down my parking garage it shifts at way too low of an rpm. So as I'm driving slowly it feels like its in some sort of limp mode if I try to accelerate, until I get out on the street and force it to downshift. Then the crackle comes back randomly after several minutes of driving. Wasn't like this when I first got the car.
Super Member
Joined: Nov 2015
Posts: 721
Likes: 74
From: NYC
2016 c450 / 2016 VW Jetta 1.8t / 2006 Wrangler X
Just a follow up here.
I took my car to the dealer on Monday and drove with their tech foreman. My service advisor just reached out with the following: The bad news is it will not be ready today, the better news is, it will be ready tomorrow with all the correct noises from the exhaust. We were advised to reprogram the engine computer with new coding values. Something in the computer that was not seeing the higher rpm to allow the valves in the exhaust to open and close.*
Now I know based on reading every post on this site, that the c450 has a traditional exhaust without any valves. I don't see any reason to call bull**** yet because up through now, they have agreed that the vehicle is not operating within spec. Maybe they messed up and are currently installing the controllable system from the c63. In which case I will be entirely satisfied!
I took my car to the dealer on Monday and drove with their tech foreman. My service advisor just reached out with the following: The bad news is it will not be ready today, the better news is, it will be ready tomorrow with all the correct noises from the exhaust. We were advised to reprogram the engine computer with new coding values. Something in the computer that was not seeing the higher rpm to allow the valves in the exhaust to open and close.*
Now I know based on reading every post on this site, that the c450 has a traditional exhaust without any valves. I don't see any reason to call bull**** yet because up through now, they have agreed that the vehicle is not operating within spec. Maybe they messed up and are currently installing the controllable system from the c63. In which case I will be entirely satisfied!
Junior Member
Joined: Aug 2013
Posts: 68
Likes: 1
2016 C450 (no code 165 option..)
Good to hear they were able to correct the issue for you quickly. The dealer that worked on my car remains clueless and has been "working with Germany" for about a month... I sent them the detail you provided (thank you) though they will not have an opportunity to work on my car again.
Super Member
Joined: Nov 2015
Posts: 721
Likes: 74
From: NYC
2016 c450 / 2016 VW Jetta 1.8t / 2006 Wrangler X
Best of luck to you. There are a couple of codes on that sheet that may mean something to your tech. It might even be helpful to have them contact my service center directly: Rallye Motors of Roslyn.
Member
Joined: May 2016
Posts: 86
Likes: 7
C450 AMG
Well old thread I know, but my car has just stopped making the crackling noise in Sport +. Very odd.
tried the reset procedure and will see if it comes back in the next fews days of driving. Otherwise, another trip to the dealer.
tried the reset procedure and will see if it comes back in the next fews days of driving. Otherwise, another trip to the dealer.
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