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I occasionally experience issues with the gearbox not kicking down in my 2006 W221 S320, despite the fact that it has been operating perfectly. With little over 95,000 miles on the odometer, I had the gearbox serviced by a highly regarded Mercedes expert; afterward, everything seemed to be running well again, but now it's happening again. It continues to hover in seventh gear even after floor-shifting, and it seems to fly into fifth gear independent of throttle input. It returns to its normal gearing when you reduce speed, albeit with a noticeable harshness in the third gear and down. Any advice would be greatly appreciated; I've tried resetting the gearbox, and while it works for a few days, it comes again suddenly.
Thank you ahead of time
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Vehicle 221 gearbox issues
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RIVERPLAZAAA
- Posts: 43
- Joined: Mon Feb 02, 2026 8:42 pm
Where is the kickdown switch located under the throttle pedal?
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GoodWillHunt
- Posts: 32
- Joined: Mon Feb 02, 2026 8:37 pm
Is the electroplate being removed? See if MB STAR diagnostics can interpret the codes.
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davejacobs
- Posts: 29
- Joined: Mon Feb 02, 2026 8:34 pm
have you made sure that the throttle pedal assembly's kickdown switch is operational?
Underneath some of these, you might find a switch for the brake lights and another for crank down. To remove the pedal and check the switch(es) on my 2006 MB, all you have to do is unscrew one plug and bolt.
Underneath some of these, you might find a switch for the brake lights and another for crank down. To remove the pedal and check the switch(es) on my 2006 MB, all you have to do is unscrew one plug and bolt.