Hello,
I have the new TCU tune with the 4-Mode what you can change with the W/S switch. After driving it now for over 400 miles I'm mostly happy with it but I have two problems. So I want to ask others with this tune if they have the same issue.
First if the outside temperature is under 45°F the TCU changes the gears only above 3000 rpm, that's a lot to high for a cold engine. OK, you can go in manual mode and switch but that's not a real solution. If you drive for 10 minutes and the transmission gets warmer the issue disappears.
The second error is in manual mode. If you accelerate full throttle and come into the engine limiter the gearbox switch to neutral and you can't switch any more also in other driving profiles. You have to stop, switch the engine off and start it again to solve this issue.

What are your experiences with this tune?

 

The first problem sounds like the transmission fluid is not coming up to temperature. The ambient temperature is not the actual factor. For the second one, I ran into this with my V8 swapped car. It has to do with torque protections built into the TCU. Have your tuner raise the limits. Additionally, I found that the TCU does learn a bit, and that several less than 100% runs up to redline and back while letting it shift automatically seemed to alleviate some of these problems.

 

Hi Viper-666

I write those tunes and sell them through the Mercedes Swap Shop in the USA. The first issue is as Neil suggested, you need more temperature in the fluid. The fluid pressures are derived from the Pressure Control Solenoid "PCS" table. This table maps fluid temperature vs. RPM to derive PCS current. The lower the temp and rpm, the lower the pressure. This table only starts at 25deg C (77F). You might not have enough pressure to change gears before 3000rpm. If you're running brown top solenoids then the values in these tables would be stock, but if your running blue tops then these initial values would have been revised to reduce "clunkyness" at low speed/load when you first start driving. I haven't heard of your problem before but at your low temperatures those initial values might need be modified.

The TCU and ECU limiters need to be co-ordinated. Your TCU has full manual mode enabled, if you're in manual mode the transmission wont change gear, you need to change gear before you hit the ECU limiter. The ECU wont like it when you hit the limiter and may cause the problem you've described. Full manual mode is really only useful for dyno testing, it means that you can put the car in 4th gear, punch your foot down (and the transmission wont kick down) then run the engine up to the redline. If you want the TCU limiter to be hit first when in manual mode then I can turn full manual off and it will change when it hits the normal TCU limter?

I hope you're enjoying all the other aspects of the tune and I'm always happy to revise any issues, just contact Josh and he'll sort it out for you.

 

Hello Andrew,
first thank you for the answer. I drove before this TCU tune also a TCU tune from Germany. This has also a manual mode. There I don't have any of the two problems. Your right you should not go in the limiter, but in first or second gear this could happend if you overtake a other car. If the gearbox goes in neutral this is a safety problem, also when you on the highway and have to stop to get the transmission back working.
The thing with the not shifting when the transmission is very cold has the german TCU tune also in a early developing version. This happened only on N/A Crossfires SRT was fine, there is something different between these two when the transmission (or the engine) is cold. But the programmer found the issue and could solve it. Also the original TCU hasn't this issue so the pressure for shifting can't be the problem.
And I have contact Josh, he says I have to wait 300 miles because the TCU learns how to shift and that he newer heard about the problem with the high rev shifting when the transmission is very could.
Greetings Andre

 

No problems Andre, I'll sort it out for you!

 

Thanks to Andrew,
he sorted out the two problems I have, the second issue that in manual mode the TCU goes in neutral was my fault, because I have a ECU tune with a higher rev cut up. But Andrew also fixed this issue!
So now I can fully recommend this TCU tune it's so much better as the stock TCU.