Hi all,


Car details:

• 2018 C 220 d (W205 T-Model)
• OM651 + 9G-Tronic (725.0)
• ~107,000 km, full Mercedes digital history
• ATF + filter were never changed before the recent service

Symptom

Very specific situation:

• ~80 km/h in 6th gear, Comfort mode
• Stronger throttle → kickdown 6→4 up to ~3500 rpm
• I then fully lift off
• Gearbox upshifts 4→5
• Right after engaging 5th, with no throttle, there is a noticeable jolt and a small RPM blip

No warning lights, no limp mode, all other shifts feel normal.



What’s already been done:

Recent full ATF service at Mercedes workshop:

• New pan with integrated filter
• ATF to MB 236.17, ~9 L used
• Level set by overflow method with Xentry, at correct ATF temperature
• No leaks, no fault codes in TCU

However:

• No standstill / gear adaptation done in Xentry
• Only a short teat drive was perfrmed
• Workshop says “not completely normal, but not a big problem, just monitor it”

Behaviour is unchanged after the service.

Questions

1. Has anyone with W205 C220d / 9G-Tronic had a similar 4→5 jolt after kickdown + full lift-off (with RPM blip, no errors)?
2. Did standstill adaptation / gear adaptation in Xentry improve or fix it for you?
3. In your experience, does this sound more like:
   • normal 9G quirk,
   • TCC / torque converter lock-up behaviour, or
   • early valve body / mechatronics issue?

1. As long as there’s no slip and no codes, is this usually safe to live with, or would you treat it as something that should be addressed sooner rather than later?

Thanks in advance for any input from people who’ve dealt with similar 9G behaviour.

Try it. You don't need Xentry. If you search on-line I'm sure you can find the procedure. Not sure, but this may do it:

thanks for the suggestion, i tried it, but nothing changed. Its doing it at comfort mode though, I might as well try and drive it on a different setting and see if there would be any jerking.

Today Lueg AG dealership in Essen, Germany replied to the case as well:

To reset the adaptive transmission on your 2018 Mercedes C220d, use the Key-On Pedal Method: ignition on (no start), press & hold accelerator to the floor for ~30 seconds, turn ignition off (still holding pedal), release pedal, wait 2 mins, then start and drive gently for 10-15 mins to let the TCM relearn your style.

Or, try this:
[Edit] I see I missunderstood you. When you said "Jolt after 4→5 upshift after proper ATF service" I took that to mean it didn't jolt until after the service. I see that is not what you meant. It's less likely the reset will help, but I'd still try it.