|Topic Review (Newest First)|
|04-22-2019 03:42 AM|
Interesting. That sounds hopeful. I'd always been told you couldn't virginize one that had already been married to another transmission like a used one from a wrecking yard. It always seemed to me that with all the computer whizzes out there that anything could be reprogrammed.
learn something new every day.
|04-22-2019 03:22 AM|
|i860||NO, you can't virginize the c/p with Xentry no matter of the access level, developer or not. For that, you need special hardware like avdi,vvdi etc.|
|04-21-2019 04:46 PM|
Although, I thought I saw that the engineering edition allowed a person to virginize an ECU and even to bypass SCN coding. I guess until the adapter gets here and I get some time on it I won't know for sure?
|04-21-2019 02:55 AM|
|i860||Just take care, once is personalized the c/p you can't go back. If you screw it up you need to virginised again ( you lose warranty also ).|
|04-20-2019 10:17 PM|
I ordered up the conductor plate from MB. The $5,600 CAD for the transmission turned out to be $7,000 CAD without a valve body or conductor plate. $3,000 more for them so....$10,000 CAD.
Given that, I said to myself, spend the $2,000 CAD for the conductor plate/service/ECN etc and then if the trans fails later I can re-build it myself for roughly $650 + my time - case closed.
And....as it turns out....there *might* be a shop here that can do the SCN coding. Turns out, it's an old friend from back when I had a shop. So we'll see what happens next week. Either way, I'm just glad to finally have the ball rolling and to have finally picked a path forward.
Many thanks for all the suggestions and advice!
|04-20-2019 05:56 AM|
|i860||The c/p will be virgin so you still need online scn and xentry for initial startup, initialization and personalized.|
|04-19-2019 08:50 PM|
|marvin-miller||I agree. This is why I mentioned getting a reman unit from Mercedes which are done in Germany at MB. It should include all updates including conductor plate and all the other updates that have been done to the 722.9 series.|
|04-19-2019 08:48 PM|
If you go with Re-man, be careful where you go, there is a huge difference between factory re-man and rebuilt from a transmission rebuild facility. I've been buy parts for cars, truck and heavy equipment for 50 years, and I would take a factory re-man over a new component, and I shy away from rebuilt unless there is no other choice because of price or availability. Factory re-man is stripped cleaned and every part that will go back in is carefully inspected and meets factory specs or it is replaced with a new part, either by the factory or an authorized re-man center. All wear parts are replaced with new, and it is tested.
Rebuilt from a transmission rebuilder may end up with any part that is "Good Enough," and sometimes the part is a "Good Enough" part off the shelf that they saved from another transmission that could not be rebuilt economically. The factory re-man will cost a little more than local rebuild but unless you know the guy doing the local rebuild, you pays you money and you takes you chances.
|04-19-2019 08:18 PM|
|marvin-miller||Yeah, I have one. And, as mentioned, captured the transmission several times while the issue was cropping up. Bottom line is, it's not the speed sensors. Replacing them will do nothing. The problem is either in the TCU or the ribbon cable. My money is on the ribbon cable but without knowing what Mercedes is changing on the reman plates we will never know 100%. But the fact is, when you reset the TCU with key on/key off the sytem comes back. If it were a sensor, it would not. We also know, 100% that this issue always seems to crop up when stopping at a light. For me, that means fluid slosh. What can fluid slosh affect? The ribbon cable.|
|04-19-2019 08:15 PM|
|Dana Teresa||If you are going to work on these these things you have to have a good diagnostic computer not a scanner. You don't really need an MB Star, I have had one for along time because that was all that would work on a Mercedes. It's cumbersome and more complicated to operate and only works on Mercedes. There are several good ones out there that will work on any make car, from as low as $700 for the Autel MaxDas 808 which I have and it will do anything you want except ECU, TCU programing. If you want to do that, there is the MaxDas 908 for around $2,000 and will also work on any make car. Cheap scanners give you basic information about codes thrown, but you can't dig into all the components and check them out, a good diagnostic computer will. Probably other good ones out there by now, but the Autel is the one I have and no complaints. I carry it in my trunk to check out cars I may be interested in buying, and checking out other people's cars that I may have to work on before I take them to my shop. I only do this as a sideline, and only Mercedes cars because I love how easy they are to work on compared to most cars.|
|04-19-2019 08:08 PM|
Originally Posted by Dana Teresa View Post
I would think that Mercedes knows how to reman their own transmissions.....I'm guessing you haven't looked at my thread where I go into this in some depth.....
|04-19-2019 07:59 PM|
This is a list of common problems with the 7-speed 722.9xx transmission:
Transmission does not shift gears or work properly until it warms up.
Delayed or unpredicted shifting of gears.
Upgrading the TCU software and resetting the transmission shift points may solve this problem. You will need either the dealer or an auto repair shop that has Mercedes Star Diagnostic C3 or C4 diagnostic computer.
Transmission slips between 1st and 2nd gear.
As soon as this is detected by the TCU, transmission goes into limp mode. Turning the engine off and then on may temporarily return the transmission to normal operation.
Accelerating from a stop light can cause the car to get stuck in 2nd gear, limp mode.
Hard shifting transmission problems.
The most common fault codes of the 7 Speed Automatic Transmission are
P0717 Input Turbine Speed Sensor Circuit No Signal
P0718 Input / Turbine Speed Sensor Circuit Intermittent
P0700 Transmission Control System TCS Malfunction
P0748 Pressure Control Solenoid ‘A’ Electrical
P0778 Pressure Control Solenoid ‘B’ Electrical
P0798 Pressure Control Solenoid ‘C’ Electrical
P2716 Pressure Control Solenoid “D” Electrical
P2725 Pressure Control Solenoid (E)
P2734 Pressure Control Solenoid ‘F’ Electrical
P0717 Input/Turbine Speed Sensor A Circuit No Signal
U0101 – no communication with the TCM
This problem is usually fixed by replacing the conductor plate or the valve body which depends on the VGS version. If a new TCU is installed, it will require programming to match the VIN of the vehicle.
Related Failure Codes
Error Code 0717 – The signal from component Y3 / 8n1 (turbine speed sensor (VGS)) is unavailable.
Error code 0718 – The component Y3 / 8n1 (turbine speed sensor (VGS)) is defective.
Error code 2767 – The signal from component Y3 / 8n2 (Internal speed sensor (VGS)) is unavailable.
Error code 2768 – The component Y3 / 8n2 (Internal speed sensor (VGS)) is defective.
|04-19-2019 07:39 PM|
From 04 to 08 most if not all of the 722.9's were a VGS1plate, and you had to replace the valve body to install the newer VGS2 or up plate.
Typically when the valve body or conductor plate fails you may experience the following symptoms:
Transmission stuck in second gear. Limp Home Mode
Shifts from first to second gear then it stays in that gear.
Transmission, will not shift into higher gears.
Can not drive at speeds over 40 mph.
Check engine light is ON.
Erratic shifting of gears.
Jolting while changing gears.
Engine RPMs are high but car doesn’t move.
Besides the speed sensors there are two fluid level sensors on the plate.
Far as I can remember there were
VGS1, VGS2, VGS3 versions, the 2 and 3 you don't have to change the valve body. May be a VGS4, but I only know the first 3.
As for ribbon cable sloshing around, all the wiring inside the transmission from the outer plug to the TCU is encased in plastic, there isn't a ribbon cable floating around in there. That doesn't mean there could not be a bad connection inside that plastic cover.
|04-19-2019 07:24 PM|
If you go with a reman transmission, make sure it has the latest valve body and plate in it,
there have been several upgrades to try and cure these problems, and I'm not sure if they ever got it completely fixed. Some will run forever, some will have problems.
|04-19-2019 07:16 PM|
|Dana Teresa||Have you checked the plug to the transmission and the shifter connections at the shift lever? Another problem in the transmissions is fluid wicking up the wiring harness from a faulty plug at the transmission. The wicking is more common in the 722.6 transmissions, and can go as far as wicking into the transmission TCU. The shifter end can happen to all of them. You should have been able to tell the general condition of the clutches by what the oil looked like when you drained it. If it doesn't know what gear it is in all the time or is hunting, tt could be a bad connection, or a computer glitch. The clutch pac side of the transmissions is really pretty tough as long as you don't run it out of fluid.|
|04-19-2019 05:49 PM|
I've been there before and ultrasonically cleaned the solenoids, the conductor plate and stripped the valve body and cleaned it inside and out. This included draining the torque converter and installing the new updated filter and tranny pan magnets. There's a thread on it going through all the diagnostic steps drilling down to the ribbon in the conductor plate or the TCU itself.
Without knowing specifically what Mercedes is doing when they reman the plates we may never know what the real problem is/was. My educated guess is fluid slosh in the pan massaging the ribbon cable causing it to flex and eventually crack. One thing we're sure of is that it's not the speed sensors in the plate. If they were defective then they would not come back to life after Key On/Key Off. What we're seeing with the scantool when the issue occurs is that the TCU does not know what gear the car is in or what gear it is supposed to be in. The conclusion we came down to is that the TCU itself is kaffing causing it go into limp-home mode. This could be as simple as a power/ground problem or what have you. This is what leads me back to the ribbon cable as the most likely culprit.
Either way, we've drilled the issue down to one of two things, ribbon cable or TCU. One thing it is not is the speed sensors themselves. As mentioned, I have a hot air re-work station so replacing the sensors for me is very easy. I would have done that if I thought they were actually defective.
Because basically 100% of the issues are reported after stopping this lead me to fluid slosh flexing the cable. If you think about it, as you drive, the fluid is constantly moving fore/aft and side to side.
Given that shops have reported comebacks when replacing the sensors either themselves or from 'reman' 3rd party companies, and my own experiences, I would not go this route at all. However, I have heard from two people that installed reman OE Mercedes plates and went more then 5 years and 50,000 miles with the issue never occurring again.
So, I was looking at going that route. However, it's probably $3K for the dealer to install the plate and it's $5,600 for a reman OE transmission. I'm leaning that way since the clutches have taken a beating due to the conductor plate issue. A reman trans will have the new plate, new clutches and all the updated parts.
|04-19-2019 05:30 PM|
|Dana Teresa||O.K. since I am just sitting here playing, I'll give you some more tips. Before you put the valves back in the plate, take the valve and look at the bottom. There is a tiny screen there, carefully clean it off, but don't just blast it with an air nozzles you will blow the crap up into the valve. If you have an air nozzle with a suction tube on it you can suck it clean and maybe use a small brush to loosen the gunk if there is any. Also on the bottom is a copper plate that contacts the buss bar on the plate, make sure it is clean and shiny you can use a pencil eraser to polish it up. If you send the plate to Circuit board Medics, they will be checking the wiring and hooking up the computer to check it out. Maybe make a note for them to check the cable extra carefully if you are concerned it may be a problem.|
|04-19-2019 05:07 PM|
|Dana Teresa||For the 722.9 plates, I've only got a few years and maybe 30,000 miles so far no problems.My E-500 had 130,000 on the car when I changed the plate for transmission issues. Also why I got the car for $4,000 from a used car dealer. He was looking at several thousand according to Mercedes to fix it, I bought it and it cost me around $400 including fluid and filter change. If you notice my list of toys, I have gotten every one of them for little or nothing because I could fix them for hundreds while the owner was looking at thousands to have Mercedes do it. The 722.6 plates I've changed were all preventative maintenance on cars with over 100,000 miles on them, The 722.6 is cheap directly from Bosch, I think around $150 brand new, but they don't have a computer on the plate, just 6 valves and a few sensors.|
|04-19-2019 04:51 PM|
|Dana Teresa||By the way, if you have never done this before there are several Youtube videos out there including one from a transmission repair instructor. It is really very easy and simple to do, with one very important thing to remember. There are 6 shift valves on the plate, when you remove them keep them in order so that they go back in the same holes, they all look the same and will all fit into any hole but they are each factory set for that particular place on the plate and you can not swap them into different holes and have them work correctly. It's not difficult, just don't take them all out and throw them in a pile. I use an old egg carton to keep them in until the plate comes back. Mark the carton so you now which end corresponds with the front of the plate. Set it next to the plate and remove the valves and put them in the carton in order, close the carton and tape it shut or wrap a rubber band around it and put it somewhere that it won't be messed with. Same procedure on the 722.6 plates, everything else is pretty straightforward and simple. Merc transmissions are really the simplest automatic transmissions I've worked over the past 50 years. Keep the area everything clean and don't get crap in it.|
|04-19-2019 04:44 PM|
|marvin-miller||So...how many years/miles have you got on the reman plates ?|
|This thread has more than 20 replies. Click here to review the whole thread.|