722.9 Transmission Conductor Plate Repair Could Save $1000s

The 722.9 transmission is an exceptional mechatronic design that can be found in hundreds of thousands of Mercedes-Benz vehicles built from the mid-2000s up until around 2020. Mercedes vehicles are known for impeccable construction and a long service life. But even if the rest of your 722.9-equipped Benz is in great shape, there is one component that can ruin your day (or week or month). It can be as simple as failing solenoid o-rings or a more comprehensive conductor plate failure in your 722.9 transmission. It doesn't have to be that way if you are willing to get at the root of your 7G-Tronic's common failure point: The 722.9 conductor plate. We strongly suggest that you remove the 722.9 valve body and repair the conductor plate at the first warning signs. Think of it as an advanced fluid and filter service. If you follow this advice, you can avoid thousands of dollars in damage to other parts of the transmission.

The 7G-Tronic 7-speed transmission was used in a wide range of Mercedes Benz vehicles from mundane C-class variants to high-performance applications like this stout AMG E63 sedan. The 722.9 can definitely handle serious torque.

What is the Mercedes-Benz 722.9 Mechatronic Conductor Plate?

Gone are the days when automatic transmissions were called "slushboxes" and operated purely on hydraulic pressure and throttle input. Today’s modern transmissions are packed with sensors, solenoids, and wiring all designed to work together for efficient gear selection. The 722.9 7G Mechatronic 7-speed transmission is essentially a robot. It's an impressive successor to the previous 722.6 5-speed transmission but at the cost of increased complexity. The conductor plate is attached to the transmission valve body and acts as the transmission control module. Each conductor plate is programmed to work with its paired transmission, making it difficult to just swap out a new or used unit. 

Here it is: The 722.9 Conductor plate for the 7G-Tronic 7-speed transmission. Solenoids with O-rings fit into the large holes and the TCM is small and fits under the rectangular plate marked "Siemens".

Signs of a Failing Mercedes-Benz 722.9 Mechatronic Conductor Plate

If something seems off with how your Mercedes-Benz drives, don’t just ignore it. You may notice the following signs of a conductor plate problem:

• Intermittent gear shifting 
• Delayed shifting
• Rough gear changes
• Transmission goes into limp home mode
• The transmission is stuck in one gear
• Can’t manually select gears

If any of the problems listed above sound familiar, stop driving your vehicle, and get ready to troubleshoot the issue. Service will most likely include raising the vehicle, draining the fluid, and removing the transmission pan to access the filter and ultimately -- the valve body and conductor plate. If the issue is related to the conductor plate, remove it and send it to UpFix for service.

But we're getting ahead of ourselves. If you have a good OBD II diagnostic tool you can scan the on-board computer for stored transmission trouble codes:

• P0705
• P0715
• P0716
• P0717
• P0718
• P0720
• P0721
• P0722
• P0723
• P2200
• P2201
• P2204
• P2205
• P2206
• P2207
• P2766
• P2767
• P2768

Your scan may also show that the signal from the following components is not available or defective:

• Y3/8N1 Turbine Speed Sensor
• Y3/8N2 Internal Speed Sensor
• Y3/8N3 Output Speed Sensor
• Y3/8S1 Selection Range Sensor

While not the only problems associated with a bad conductor plate, these are the most common problems we’ve found.

With its magnesium case and sealed design, the 722.9 7G-Tronic 7-speed transmission is sophisticated and durable. The conductor plate CM is its Achilles heel.  It's best to remove your conductor plate and have it serviced before trouble starts -- like as part of your 40,000 or 80,000 fluid and filter service.

What Goes Wrong with the Mercedes-Benz 722.9 Mechatronic Conductor Plate?

Due to the complexity of the unit and the harsh environment inside the transmission, the speed sensors are a common failure point. Compounding the issue are multiple speed sensors. If the transmission can’t tell how fast things are moving, it can’t choose the proper gear at the right moment. The result can be gear-shifting mayhem or no shifting at all.

Keep in mind there are three different versions of the 722.9 7G Mechatronic transmission conductor plate, each with its own software programming. They ARE NOT interchangeable. Luckily you can determine which version you have by looking near the part number, there will be a large 1, 2, or 3 denoting the version.

UpFix can repair the 722.9 conductor plate in the following models:
C-Class

2011–2018 C63 AMG and C63 AMG Black Series models (W204) 

2014 C180 models (W205)

E-Class

2009–2016 E200 AMG 7G-Tronic and E63 AMG models ( W212) 

2009–2013 E200 AMG 7G-Tronic models (W212) 

S-Class

2013–2017 all models (W222) except Maybach S 500 and Maybach S 500 4MATIC

2017–2020 V12 only models (W222) 

SLK-Class

2011–2015 models (R172)

CLK-Class

2005–2010 models (C209, post-facelift)

Links:

Conductor Plate Repair Service:

722.9 Conductor Plate Repair Service for Mercedes-Benz 7G-Tronic

725.0 Conductor Plate Repair Service for Mercedes-Benz 9G-Tronic

FCP Euro 722.9 Transmission Service Kit

We really like the Liqui Moly fluid and filter service kits from FCP Euro available in 7-liter early style and 10-liter late style If your car has 40,000 miles
10 Liter Late Style 722.9 Transmission Service Kit

7 Liter Early Style 722.9 Transmission Service Kit

Why Choose UpFix?

If you are ready to put an end to the shifty antics of your 722.9 7G Mechatronic transmission, then UpFix has the solution. Our team of expertly trained technicians has certifications for IPC, J-STD, and General PCB troubleshooting. We use high-tech BGA rework stations that can handle delicate, sophisticated repairs for the highest results. Our state-of-the-art Weller soldering irons create precision soldered joints for long-lasting connections. At UpFix we have the skills and the equipment to do electronic repairs right.

Removing your original conductor plate is an involved process, but not one outside the realm of a confident DIYer. You will need to remove the transmission drain pan and valve body, so be prepared with a good service manual. 

This service is for the conductor plate only, so you will need to carefully separate it from the valve body. If you are unsure if the problem is the fault of the conductor plate, do not send in your part. If you do send in your conductor plate and no faults are found, or if your part is beyond repair, you will only have to pay shipping costs. In some cases, an additional $39.99 bench test fee may be applied depending on the situation. 

Once you are sure you have a conductor plate problem place your order, and follow the shipping directions found here. There’s no core deposit required and you’ll have your conductor plate back in just a few days ready to reinstall. And since it is your own original part it will be ready to plug-and-play, no programming required! Our work is backed by a one-year warranty. So don’t scrap your beloved Mercedes-Benz over a transmission problem that can be easily solved for a reasonable price, UpFix it today!