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After calling 5 shops in my area I found a shop that does quality work.
The Shop Tech called me to ask some questions.
Turns out this particular car, an 04 wants not only the TCU replaced but the entire valve body. That's why I got locked out of the SDS. He showed me the screen. That's what his screen showed. The car was requiring a valve body swap when changing the conductor plate.
So; my query is IF I can resolder the broken connections on my original board, Could you fool the main ECU into believing the replacement is the original? Or send the rebuilt virginized board back and buy a new MB blank with no guaranty it''ll still ask for a valve body. OR do I just just buy another valve body and just finish out coding of the replacement?
The tech was an MB rep and was going to put in a call to his old regional service rep he is friends with
This going to take some technical background searches.
I'm a bit lost on this one, Hary. The valve body has no electronics in it, so I don't see how anything would "know" if it was replaced or not. My understanding of SCN coding is that it basically just writes the car's VIN to the EEPROM in the component, but does it in such a way that it is encrypted. All that happens is that the ECU polls the TCU (or any other SCN part) for its data, which it then decrypts. If the VIN matches, all is good. I do understand that the earlier units needed a new valve body, but I thought that was because they were upgrading from a VG1 conductor plate to a later revision which did use a different valve body. But again, this is just all stuff I've learned from studying other people's challenges online!
Like you Rudeney I didn't get the disconnect about not being able to finish the the encoding.
The tech said there was a catagory for plate and valve body replacements. Would it be worth a shot and try that ?
The tech showed me the screen shot and I think it possibly could be because of a simple mis match of reading and stored info. If you look at the one screen that says if you have sensor error you can go forward with encoding. But the first thing the tech mentioned was they wiped all the error codes before starting the whole encoding process So at this point I'm not sure if they can "lie to the system" or hook up my old board and hang it off the car and re create the old tcu error codes the DAS is looking for, to agree the board has failed and only it needs replacing
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Last edited by Hary Gahtoe; 07-30-2017 at 12:13 AM.
All this headache to make the car harder to steal! I know that the DAS 3 (Drive Authorization System) is pretty hard to crack, but prior to the 722.9, one could pop in a matching EIS (ignition switch), ELS (steering lock), ECU and SmartKey and off you go . With the 722.9, the TCU and also the AGS (gearshift module) now require SCN coding and a mismatch will cause the ECU to shutdown. And the R230 doesn't have an ELS anyhow. Of course they aren't really trying to protect us from car the typical smash-n-grab thieves, but from the cartels that grab cars and ship them overseas.
All the above comments make me think that some of these model year changes are nothing but trouble to the owner. I'll stay with my '03! It seems a bit less complex. Best of Luck to you Hary, you've been a big help to me in the past. I wish I could provide you with a fix for your trans.
Thank you moretech but if I can at least shine a little light on others future problems then so be it.
As as to my particular situation, I'm going to talk to the tech about the rebuilt plates compatibility (IF they can force an encoding process) to see if there's possibility of incompatibility or shift program issues after initializing it.
Last edited by Hary Gahtoe; 08-16-2017 at 11:57 PM.
Reason: Updated info
The car now runs perfectly. To be fair the tech went way above and beyond to complete the repairs. If it wasn't for him I would've never had closure here.
He contacted his old regional MB service rep and brainstormed a solution.
My particular car was a very early 722.9 production model and yes MB dictated a valve body in conjunction with an updated new conductor plate to remedy a trans repair. Problem solved now the car up shifts,downshifts decel hold and firm manual shifts.
So you did replace the valve body or not? I think I'd like to hear a final "summary" of what you did and what finally worked!
I skipped thru a lot of back and forth problems and diagnosis.
After installing the rebuilt virginized plate myself all I get is 1-2-3.
Realizing I'm not able to code it I Find a service shop near me that can actually try to diagnose situations The service tech (who was a prior MB Star tech)at the shop says the car isn't accepting the board and later gets info that MB is telling the car via the diagnosis screen it (the board)needs to be updated and must be matched with a corresponding valve body.
Well after the shock wears off it makes typical German sense why it wouldn't let me finish coding the trans myself and where it stopped coding the TCU and I agree with replacing both parts
The MB area service rep said early production run 722.9's had a high failure rate and after autopsies it was noted the units were only effective after both were replaced as a retrofit. I have no idea of a cutoff date or assembly line correction period on the 7G's.
Trans now works great and they gave me a 18 month warranty.
Yikes! Sorry that the DIY conductor plate job didn't work out. What did they charge you for the plate+valve body? I had the plate done on the CLK and it was $1400.
They must've had almost 3 hrs labor /diagnostics they put in before they even started the replacement so I felt $1800 was very reasonable. I was bracing for upwards $3000 considering the tech spent close to 2 hrs talking with his old MB supervisor. Plus they cleaned up the rebuilt and packed it up for me to get back a full refund of $400 so I was extremely pleased knowing they did an entire service correct and complete the first time.
After I took it home, we went for several 50-75 mi blasts. I put it thru some real tough tests. Passed with flying colors. I went back and gave the service tech a healthy, well deserved tip
07-27-2017, 04:46 PM
. With the 722.9, the TCU and also the AGS (gearshift module) now require SCN coding and a mismatch will cause the ECU to shutdown. And the R230 doesn't have an ELS anyhow. Of course they aren't really trying to protect us from car the typical smash-n-grab thieves, but from the cartels that grab cars and ship them overseas.
