RawBenz

I've been driving my wifes C63 for the past week as we've swapped cars for a little while.

Her car used to pop and crackle on slow downshifts from 3rd to 2nd gear in M mode at approx 40km/h.

I've noticed that's disappeared now. And just gurgles.

Had the car checked for air leaks (exhaust) just in case it's losing back pressure but they only found a tiny hole and it was rectified. It's still not crackling and popping like it used to.

Even in C and S mode it used to crackle, pop etc when it automatically downshifted through the gears especially at low speed from 3rd to 2nd.

Now it used to pop and crackle for a good 6+ months and has just stopped over the past few days.

Could it be the fuel?
I know it sounds stupid, but any insight would be good, as i'm worried it may be leading to something more serious.

nkc

reset the TCU adaptations, and see if it helps the shifts

RawBenz

How do i do that?

nkc

Do this

1. Turn the ignition key to the "on" position which is just before you crank the engine to start.

2. Press the accelerator to the floor and hold for 5 seconds.

3. Then turn the key to the off position but do not remove the key, then release the accelerator.

4. Wait at least 5 minutes, the ECU is then reset.

The ECU rest procedure only erases the adaptive transmission and throttle settings. It does not erase any of the fuel, timing or other programming.

RawBenz

Her car has an aftermarket tune, so it won't mess with that?

nkc

mine has a eurocharged v5 tune, i do this procedure every month, just for the fun of it, since the car is parked most times,and my tune is perfect, mind u, i am a million miles away incase the tune is messed up, so ur good to go.........

RawBenz

Perfect i'll try it on her car in the morning
Thanks

nkc

your welcome...... i believe it would clear things up consdierably

RawBenz

Do you know what would've caused it?

nkc

well am no magician, but if i follow what u said earlier, one its wifeys car, she isnt going to be driving in S or S+ always, i reckon maybe C all the time, even if not, she would baby the car more and not open it up, eventually the car will start behaving like a grannys car, because the TCU will be adapted to the slow driving, and u know the AMG needs a floggin no& then, so it requires opening it up, which the TCU reset will achieve , then you can flog it and see how it responds. I am sure the car is seeing my chats and cant wait for the morning to bare its teeth........ enjoy in good health

VaclavSV

So this will not remove my tune?

Jbobiccus

It will not remove your tune. I still am hearing from some people that the reset procedure doesn't work. The best way to be sure the adaptations reset is to leave your battery unplugged overnight.

papashango

Also how would that reset procedure works on car with button start?

Rob CL

I'd leave my foot off the pedal, and press the button twice, to place the ignition into "position 2" or "ON".

Patrick B

Just pull the button out. it's a standard, MB key for ignition behind the button.



Patrick

bhamg

OP, if you're in the "low-aggression" adaptation mode, a reset (if in fact it works - it's never been authoritatively verified as a "real" procedure here, ever) will not get you where you want to go. I do the following (7G trans), and this procedure works very quickly and reliably.

- Put your car in D3.
- Using heavy throttle, run past 5k through the three gears.
- Brake with a heavy foot.
- Repeat, perhaps four or five times.
- After that, test your adaptations by hard braking as if you were bedding pads, say from 70-10 mph.
- You should feel two quick downshifts accompanied by backfires and burbling.

RawBenz

Has this been verified?
All i want is to be able to restore the crackling and popping that's seemed to have vanished.

roadtalontsi

This definitely gets my car in kill mode. I think the message everyone is missing is.... im driving my wifes car... maybe she drives like a maniac and he drives like poooooontang.

bhamg

Yes, by an unimpeachable source!

RawBenz

D3 meaning S3? C3 or M3?
Sorry i'm not being a troll, just trying to figure out if it's C mode, S mode or M mode.
And when do you brake after running past 5k rpm?

bhamg

^ Sorry, S3. I use a hill that is perfect for this exercise. Two mostly full-throttle blasts with 8/10's braking in between gets me to the top. Just brake when you're finished accelerating, don't waste time coasting in-between. On the flat portion at the top I'm usually full-throttle for 3-4 secs, then back off for few, then fully on, off, on, like that. You could do that in M2. The important thing is to be really ON the throttle while you're doing this...the adaptations then take place quickly, only a couple of minutes total and you're done. Your closing braking run should yield two very aggressive downshifts that sound incredible (I'm talking headers, fully-catted and tune for mine).

RawBenz

Ok so let me get this straight.
You engage S mode.
After driving and the car is in 3rd gear (S3) flatten the throttle.... Go through S3, S4, S5 and change at redline or above 5k.
Brake, then repeat about 4-5x.
Then test it by braking hard from a high speed to low speed and it should drop down two gears?

Do i need to do anything with the key, reset etc?
Or do i just simply go for a drive and do this?

bhamg

Nope, I go 1 thru 3...4 and 5 would put me at way too high a speed where I am. It's all about how you use the throttle so mash it in the lower gears. I just start in S3 (1st gear) at the bottom and accelerate hard. I probably back off momentarily in 2nd and then absolutely blast through into 3rd. If you like M mode then use that exclusively. I say four or five times simply because that's what my loop allows and it works for me. My final braking run takes place in 3rd gear and under hard braking the downshifts to 2nd and 1st are very aggressive and stacked on each other. That's the adaptation you are looking for if I'm understanding correctly. What I do should not be interpreted rigidly, it's simply the approach and general principles that made sense to me and that I utilized even before the C63, like when I used to flip-flop between a 91 and 94 octane tune in a BMW. And yes, just go for a drive, the new adaptations would undoubtedly override any others anyway.

RawBenz

Ok so I've tried this and its not working. I'm confused.
I drive in M mode most of the time and so does my wife. I tried it a few times.
Is the car meant to gear down on its own in M mode when you're braking?

bhamg

Describe what you did.