I hear you. But SCN coding is a fear I’ve yet to overcome. And pressure filling a transmission through the drain port just seems weird.

Sixto
98 E320s sedan and wagon
02 C320 wagon

Is Valvoline Maxlife fully synthetic ATF safe to use in a 1999 E300D?

I had the guy st Autozone look it up and he stated that it can be used in the 722.6 transmission, is this correct?

Lots of 722.6 owners use it.

Sixto
98 E320s sedan and wagon
02 C320 wagon

Ok, so i took it to an independent Mercedes Service facility and had the transmission scanned... These were the results.

Code 124: The engine speed of engine is sporadically implausible.
Code 136: CAN communication with control unit Instrument cluster is sporadically disturbed.
Code 109: Component Y3/6n3 (speed sensor 3) sporadically faulty.
Code 147: The gear is sporadically implausible or transmission slips sporadically.

Prior to going to the shop I discovered that the fluid was about a quart and a half low due to a leak at the connector, so I topped it off.

These were all STORED codes that were pulled but the CEL kept giving a PO715 code even after I rest it with OBDII several times.

The shop recommends replacing the conductor plate for a whopping $1,200.00.

I was a mechanic for 20 years so I've decided to DIY it as I can obtain not only the conductor but a new connector, filter and gasket on line for $68.00, it's after market but has great reviews.

https://www.ebay.com/p/Transmission-Conductor-Plate-Connector-Filter-Gasket-Kit-for-MERCEDES-722-6/853691352?iid=331594680632&rt=nc#UserReviews

Also, the shop says they can put in a used transmission for$5,453.00 which is about $1,700.00 more than I paid for the car. I've found exact fit transmissions on ebay for $600.00.

From my research I gather that once the conductor plate is replaced the transmission shift must be re-learned/reprogrammed.

Has anyone every done this?

Thanks in advance!!

Those codes point to conductor plate. The conductor plate is the heart of the transmission, it cannot do anything without the computer talking to the sensors and actuators.

Be sure to follow the cable up from the transmission and verify that the transmission controller (in the control box at the right rear corner of the engine bay) is not full of fluid. The suspended graphite particles in the fluid can short the circuit board out.

The sensor with errors (Y3/6n3) is part of the conductor plate.

There are many videos on youtube about doing the conductor plate. Most important thing to observe is absolute cleanliness.

Once you get the conductor plate swapped, the connector fixed, and the computer checked for contamination I am reasonably sure that will take care of your issues.

You will have to get it scanned with the MB computer again to clear out the codes. There is also a reset adaptations, basically that is initiated in the computer and then it re-learns how to shift again based on the next few driving cycles.

Were these all the codes from every computer in the car or just the transmission computer? The 136 CAN fault would be unrelated to a conductor plate issue.

At first I'd be looking at the transmission computer for oil infiltration from the leaking connector. Oil can wick up the wires and end up in the transmission computer. While oil is an insulator, graphite from clutches is a conductor and can cause all sorts of issues when it covers a computer board.

If no oil in the transmission computer plug, changing the conductor plate would be a good next step.

I'd have to check the list but I'm pretty sure P0715 is a generic " The engine computer is seeing codes from the transmission computer, scan the transmission computer for more details. "

Did they give an itemized estimate?



I was getting Doorman brand and the parts were actually marked with a MB logo and part number, not sure if this is still the case or not.

You won't have any problem changing this, remove conductor plug ( 7 or 8 mm headed bolt in the center ) the valve body then the conductor plate is atop the valve body. Your trans is late enough so there will be some screens under the solenoids, be sure to remove and clean these.

The $ 5,453.00 estimate for a used unit it so far out there it sounds like someone in the office chose a random number or quoted a MB reman. Did they give a itemized estimate for this? For a used transmission, have a look at car-part.com it is a search site for participating salvage yards. Call the yards direct as many have not figured out e mail.

The conductor plate does not contain any logic or computers. It is just a couple of speed sensors, a thermister for trans oil temp , reed switch for neutral safety and wiring for the solenoids to attach to.

Just changing the plate should not alter trans performance other than fixing a fault. Changing fluid could alter things but I would not expect a drastic change.

Relearn procedures generally consist of resetting adaptations then x number of shifts at light throttle. I'd have to dig for info on this.

MB brand filter and connector aren’t expensive even at 2-3x the price of aftermarket. That’s not where I’d save a few bucks. Get them from a reputable seller such as Pelican, sponsors of this site or a MB dealer. Lots of claimed genuine MB parts sellers on Amazon and eBay aren’t. Symptoms - connectors leak within a couple of months, poor fitting filters allow air into the pump starving the transmission of fluid. Look up transmission whining and dropping out of gear without CEL.

Oddly, I haven’t read of aftermarket conductor plates having poor fit or short life.

Sixto
98 E320s sedan and wagon
02 C320 wagon

I have done the conductor plate job, and it is totally a DIY job, even for the novice mechanic. There are plenty of tutorials on youtube, and even a couple threads here. Something you may also come across, is a bad shift selector switch. You will move the shifter, but it does not communicate with the trans controller. It normally happens on a cold morning, after the car has been sitting overnight. I tested it by putting a space heater in the cabin a couple hours before starting it in the morning. With the cabin somewhat warm=no problem. No heater=trans would not shift, even though mechanically it was out of park, and in D.

Agreed- just used one today, bought from Pelican. The adapter plug is MB, and only $15. The filter and gasket kit is only about $16 (for the OE). No reason to cheap out here.

Next time you are at a self serve salvage yard, pickup some computer modules , connectors , OBD 2 port and 38 pin MB port ( if your car has this )

I have a setup that I can test nearly all of the computers in my 97 C280 / SL320 out of the car. This lets me go to setup screens without fear of altering my original computers.

Thanks.

I meant SCN coding for the 722.9 conductor plate and TCM.

Sixto
98 E320s sedan and wagon
02 C320 wagon

My wife drove the car and it wont shift beyond 2nd gear now. So, I received a new conductor plate and installed it today. The transmission is way more powerful but it's still wont shift to 3rd gesr or higher. Did the transmission go into limp mode and if so what is required to get it out of limp mode?

Also, my wife read on line that disconnecting the battery for one hour should reset the transmission, is this correct?

Thanks guys

More like the transmission is still in limp mode. You need SDS to clear codes at the transmission module level through the 38-pin connector under the hood. Clearing codes through the OBD port won’t clear the transmission module code, neither will disconnecting the battery.

Sixto
98 E320s sedan and wagon
02 C320 wagon

Sounds like it is in limp mode, which would you can't reset without the Mercedes computer software. Did you use a good torque wrench to tighten the screws for the valve body, and make sure it was filled to the proper level with the right fluid? $5500 for a used transmission is insane, I have seen $3900 installed for a fully rebuilt one.

So, great news. Had the transmission reprogrammed and it shifts better than it ever has since I owned it.

Thank all of you for your guidance and patience, it has made a world of difference and I am truly grateful.