Transmission won't up shift manually

[Pauljay]

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?

 

[Rashman]

Are you sure you're using manual mode properly?

Your transmission will not change up a gear automatically when in manual mode.
You have to tell it to change up by flicking the paddle/ pressing the upshift button/ tapping the gear shifter.
If you don't, it will hit the rev limiter and stay there.

However, when in manual, your transmission will change down a gear for you when you are braking and slowing down.
Depending on the gear box, it will downshift at around 1900 rpm.
This prevents stalling.

Or, your new TCU isn't configured properly.

 

[Pauljay]

Yeah, sorry Rashman! I mean when I tap the shifter for an up shift manually..

 

[Rashman]

Yeah, sorry Rashman! I mean when I tap the shifter for an up shift manually..

Oh, I get ya.
Yeah, that sounds like a probable technical issue.
One of the workshop guys on here should be able to help you with advice there - Olly, Savman, Acid etc

Hope you get it sorted.

Sounds to me like it might have something to do with your TCU..?

 

[MancMike]

Mine does?

In manual mode, if I floor it, it'll still up shift at the red line, just like it'll still down shift as you slow to prevent a stall.

 

[Pauljay]

i-CONICA

Mine used to if I shifted up with enough time before it hit the limiter. This new TCU/valve body doesn't!

Does anyone know if values need to be set via STAR?

I've already tried the transmission reset via holding the accellerator down which didn't fix it...

 

[BlackC55]

Has the TCU been coded properly?

 

[Pauljay]

Hi Ollly!

I don't know what the Mercedes dealer did! I do know that it took them 3 goes to realise that there wasn't a programme on the 3 TCUs they ordered for me as none of them worked!

I don't want to go back to them as I've lost confidence and it's been about 3 months even though I only noticed around 3 weeks ago!

I'll go to my local indie and hope that there is something they can do with their STAR machine.

 

[MancMike]

Mine used to if I shifted up with enough time before it hit the limiter.

No that's not what I meant. If mine is in manual mode and I don't touch touch the tiptronic, it'll still up shift before it gets to the limiter, i.e, it's not possible to hit the redline in mine.

Anyway carry on.

 

[Pauljay]

No that's not what I meant. If mine is in manual mode and I don't touch touch the tiptronic, it'll still up shift before it gets to the limiter, i.e, it's not possible to hit the redline in mine.

Anyway carry on.

I see!

I think because mine is a W208..