Transmission won't manual up shift
Thread Starter
Senior Member
Joined: Mar 2008
Posts: 436
Likes: 1
From: Surrey, England.
'00 Mercedes 430/55 clk cabriolet
Transmission won't manual up shift
Hi Guys,
I've a problem with my gear shift point.
When in auto my transmission shifts fine, but when in manual, driving hard, as the revs approach the limiter it doesn't shift up!
Even if you lift off slightly or tap for an up shift early it stays in the same gear if you have your foot planted. You have to lift off for a second or two before it changes up!
All other times and on manual down shifts my transmission is fine.
Coincidence it may be, but I had a new valve body and TCU installed after the old ones got ruined by oil!
The old TCU changed up if you made an up shift before the red line!..
Does anyone know what's happening?
I've a problem with my gear shift point.
When in auto my transmission shifts fine, but when in manual, driving hard, as the revs approach the limiter it doesn't shift up!
Even if you lift off slightly or tap for an up shift early it stays in the same gear if you have your foot planted. You have to lift off for a second or two before it changes up!
All other times and on manual down shifts my transmission is fine.
Coincidence it may be, but I had a new valve body and TCU installed after the old ones got ruined by oil!
The old TCU changed up if you made an up shift before the red line!..
Does anyone know what's happening?
MBWorld Fanatic!
Joined: Nov 2001
Posts: 1,258
Likes: 209
From: Boston North Shore
2001 CLK320 Cabrio
First of all, sorry to hear that the ubiquitous pilot bushing leak (e.g. wicks transmission fluid into the TCU and destroys it).
Surprisingly, while a very common issue, and MB has come up with a resigned pilot bushing, which only cost about $15, there has never been a recall or campaign to replace at no cost. Go figure.
That said, per the owners manual, MB also stated that our W208 transmission fill is good for life and never requires servicing. However, after numerous transmission failures, MB has changed their mind, after numerous failures in the transmission electricals and now recommends that the transmission be serviced every 39,000 miles.
The cost is about $250 and includes replacement of the filter, partial fluid replacement (e.g what were the German engineers thinking when they decided not to put a drain on the torque converter?) and pilot bushing (if leaking).
In regard to your particular issue, the transmission electronics are adaptive (e.g. learns your driving style) and adjusts the shift points. If the issue persists, you can reset the transmissions learning (e.g. search is your friend).
PS: Just wondering......if your interest is spirited driving, why not a BMW?
Surprisingly, while a very common issue, and MB has come up with a resigned pilot bushing, which only cost about $15, there has never been a recall or campaign to replace at no cost. Go figure.
That said, per the owners manual, MB also stated that our W208 transmission fill is good for life and never requires servicing. However, after numerous transmission failures, MB has changed their mind, after numerous failures in the transmission electricals and now recommends that the transmission be serviced every 39,000 miles.
The cost is about $250 and includes replacement of the filter, partial fluid replacement (e.g what were the German engineers thinking when they decided not to put a drain on the torque converter?) and pilot bushing (if leaking).
In regard to your particular issue, the transmission electronics are adaptive (e.g. learns your driving style) and adjusts the shift points. If the issue persists, you can reset the transmissions learning (e.g. search is your friend).
PS: Just wondering......if your interest is spirited driving, why not a BMW?
Thread Starter
Senior Member
Joined: Mar 2008
Posts: 436
Likes: 1
From: Surrey, England.
'00 Mercedes 430/55 clk cabriolet
Thanks Serndipity!
Good write up of my problem..
I've already tried a reset for the transmission, but it still didn't change up which is why I ask hoping that my searches have missed something as this particular fault I cannot find a solution for.
I'll try and see if there's other things a shop can change via STAR.
Although I do like BMWs, I prefer the look of the W208! I could have purchased a W209 or M3 but I wanted my particular car.
All the changes I've made have personalised it exactly as I'd like bar one or two things.
Great car the W208!
Good write up of my problem..
I've already tried a reset for the transmission, but it still didn't change up which is why I ask hoping that my searches have missed something as this particular fault I cannot find a solution for.
I'll try and see if there's other things a shop can change via STAR.
Although I do like BMWs, I prefer the look of the W208! I could have purchased a W209 or M3 but I wanted my particular car.
All the changes I've made have personalised it exactly as I'd like bar one or two things.
Great car the W208!
MBWorld Fanatic!
Joined: Nov 2001
Posts: 1,258
Likes: 209
From: Boston North Shore
2001 CLK320 Cabrio
Pauljay......I hear you. Although my 3 series BMW was lots of fun drive, traded it in for my CLK, because when I looked at one, my heart went pitter, patter and continues to do so.
Now that you mention it, when a transmission control module is replaced, the TCU does need to be reprogrammed with SDS (e.g. STAR).
For more information on trouble shooting and repairing the MB 722.6 transmission, Mercedes Source has an excellent 6 part video series.
In Part 6, he discusses the 'post repair' requirement to to reset the codes with SDS.
Now that you mention it, when a transmission control module is replaced, the TCU does need to be reprogrammed with SDS (e.g. STAR).
For more information on trouble shooting and repairing the MB 722.6 transmission, Mercedes Source has an excellent 6 part video series.
In Part 6, he discusses the 'post repair' requirement to to reset the codes with SDS.
Last edited by Serndipity; Oct 11, 2014 at 12:53 PM.
Thread Starter
Senior Member
Joined: Mar 2008
Posts: 436
Likes: 1
From: Surrey, England.
'00 Mercedes 430/55 clk cabriolet
Thanks Serndipity,
The guy talks a lot but gets the job done! Lol!
I'll look to see if any codes have since shown up and see if my Indie can erase/reset them.
The guy talks a lot but gets the job done! Lol!
I'll look to see if any codes have since shown up and see if my Indie can erase/reset them.
MBWorld Fanatic!
Joined: Nov 2001
Posts: 1,258
Likes: 209
From: Boston North Shore
2001 CLK320 Cabrio
Hopefully, it's just some old fault codes messing up your shift points.
However, just in case, after reading your initial post again (e.g. the issue only seems to occur during manual (e.g. paddle) shifting), so thought I'd also mention that.........
If a liquid (e.g. water, coffee etc.), is spilled onto the center console, the electronic selector module (ESM), is frequently damaged. The MB response was to design and install an improved 'resistant to fluid contamination' ESM in all W208's, produced after April 2001 (see TSB 42/01-2). FYI, the old part was A 202 267 04 24 and the new part is A 202 267 08 24.
Let us know what finally corrected your issue.
However, just in case, after reading your initial post again (e.g. the issue only seems to occur during manual (e.g. paddle) shifting), so thought I'd also mention that.........
If a liquid (e.g. water, coffee etc.), is spilled onto the center console, the electronic selector module (ESM), is frequently damaged. The MB response was to design and install an improved 'resistant to fluid contamination' ESM in all W208's, produced after April 2001 (see TSB 42/01-2). FYI, the old part was A 202 267 04 24 and the new part is A 202 267 08 24.
Let us know what finally corrected your issue.
Last edited by Serndipity; Oct 13, 2014 at 07:15 PM.
