Sam Zand

on highway speed does not downshift when trying to pass
it stays on high gear but when car is turned off and after 30 sec turned back on it goes to normal and shifts ok. ??? any ideas???

Rudeney

I suspect a throttle issue. You can try the resync procedure (below), but you may end up needing a proper diagnosis which could lead to replacing the accelerator pedal.

1. Make sure everything in the car is turned off and closed.
2. Turn the key to position 2 so all the dash lights are illuminated.
3. Press the accelerator fully to the floor, depressing the "kick-down" button.
4. Hold the pedal for 5 seconds and continue to hold it down.
5. Turn the ignition switch back one click to position 1.
6. Release the accelerator pedal, but leave the key in position 1.
7. Sit quietly and wait for about two minutes - do NOT open or turn anything on.
8. Listen for a "click" or "ping" noise form the dash.
9. Start the engine and drive the car for at least five minutes.

Sam Zand

Wow thank you I will try that and let you know 😎👍

Rudeney

Another thought - see if there is a difference between "S" mode and "C". Comfort mode requires a much deeper throttle response to downshift, whereas Sport mode downshifts much more quickly.

Sam Zand

Ok

Sam Zand

Rodney

Thanks for your awesome advice
Something happend and switching to S mode really
Made the car feel so much better
Once again THANKS 👍😎😊

Sam Zand

Sam Zand
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Join Date: Jul 2016
Location: miami
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Drives: 2008 CLK550 CONVERTIBLE BLACK ON 18's
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Rodney

Thanks for your awesome advice
Something happend and switching to S mode really
Made the car feel so much better
Once again THANKS 👍😎😊

Rudeney

I always drive in S mode unless roads are slick (C mode starts in 2nd gear, so less wheelspin).

Sam Zand

hi rodney

today when driving in the parking lot i came to a complete stop and put it in REAR gear but it did no catch the gear.... it was like natural
than i tried DRIVRE and still like natural
i tried DRIVE once more and it KICKED hard in gear
and its been fine since than. I gad it on S mode.

Any ideas??

Thanks

Sam Zand
2008 clk550

Rudeney

I'd start by checking the transmission fluid level. This is a bit of work on the 722.9:

http://benzbits.com/722_9/FillFluid.pdf