Stand alone 722.6 tcu
 

So PCS has been working on finalizing the firmware for the 722.6/wa580 transmission the last couple of weeks. I have been driving around like a mad man testing stuff. We are almost complete. Basically we have put in all the parameters that the tcu now knows actual gear ratios and completed gear shifts. This means most importantly that the tcu knows if the transmission is in the correct gear and has the ability to correct if not. It also finishes a shift on gear change complete rather than a set time. This means that the shifts are not only much quicker but also much smoother. It was always a hard balance to play the pressure and shift timer. We also have snow mode working and are working on a few other features that have been messed up with all the changes but the basic transmission operation is really solid now. Even if you manage to mess up the pressures enough that it is missing shifts it keeps trying until the shift has completed. You can also easily diagnose a missed shift in the datalogs, adjust pressures and correct the problem. I think that this will be much easier to tune on new setups. I hope to have the standalone systems with the new firmware available shortly and then on to the CAN bus for installing in factory equipped cars. This will be huge of course for the performance guys that are modifying their cars beyond what the factory tcu can deal with.

Cool, I've been following the PCS solution for a while.

From reading the Mercedes factory info, the 722.6 engages the shift solenoids only when a shift is requested ( it uses PWM for these solenoids as well ) and " ratchets " through the gears rather than speed 1 sol , speed 2 sol . . . or even a combo. The 1-2 shift soll is also used for the 4-5 shift from what I recall.

Yes, the shift sequences are initiated and pressure controls are through the pwm of solenoids. Once a shift is completed everything returns to a rest state. So you could in essence disconnect the computer from the transmission and it would stay in whatever gear it was in until you cycled the shifter. And then you would be in 2nd only. Commanding shifts is fairly straight forward but it must be sequential and because of this things must be setup properly.

While I'm guessing that this is out of my reach, what are the stand alone versions going for, or is there a price assigned yet?

The basic tcu package is 940.00. This is for the harness and the tcu. Most people need a few additional items and the average price is around 1140.00. You will also need a shifter and transmission of course. And depending on the setup a trigger wheel for the driveshaft. I am working on a setup for this but it is difficult to have something that works on all cars since there are so many different flanges on the transmission.

Nice to see this progressing. Is this an all new TCU or just a firmware update. If you recall in my conversations several years ago. On my wish list was to pick up at least tach and wheel speed over the CAN. I believe these CAN parameters wont change from year to year, unless MB is deliberately trying to screw us. I was also wondering if this will work with the newer 7 speed transmissions.

This is just new firmware. We are almost done with the setup. What I have right now works perfectly but we are making a few changes to some procedures to fine tune it.
The 722.9 is a different problem due to the imbedded tcu in the valve body. PCS is planning on working on this but with a can interface module. This will be very hard though due to the drive authorization.

I don't know anyone, myself included, with anything good to say about the 722.9. There was a good stretch where Mercedes wouldn't even sell the valve body for it in an attempt to keep the fiasco in house. I can't imagine anybody willfully putting that disaster behind anything.

If only I could mount my t-case to a 722.6, I'd be interested. Looks like I'll be prepping a 722.3 before long instead:rolleyes:

The 722.9 is not bad just not friendly. They will not sell the valve body because they are trying not to sell parts to independents as much as possible. Besides coding it requires a pretty big investment for not much return.

This is awesome news on the 722.6 controller... thanks for the update, Russell! Now who will be the first to try an installation in a 124.034/.036??

:stuart:

Hi Dave, nice to see you're here too.

I may not be the very first one, but damn close to I hope. :juggle2:

Hi Russell, my 722.6 transmission and LSD have now been installed but my mechanic is waiting on some clear weather free of snow to even try driving it down the street. Is this new firmware something that he should install before he starts the road tuning phase?

It wont effect the tune much if any. So no he can proceed.

Haven't those crazy diesel guys in Europe covered that??? I'm thinking about doing it

The diesel guys, probably, yes. But the 124.034/.036 is the 400E/500E with M119 gas engine. I've not heard of anyone converting a W124 with M119 to a 722.6 tranny... but I'd sure like to see it done!

:euro: