Repair of CVT conductor plate 722.8 Mercedes A-class B-class

722.8 - Mercedes production CVT, released in 2005 and installed on such car models:

• A150, A160, A170, A180, A200, B150, B170, B180, B200

Practically all modern Mercedes automatic transmissions have one design feature, it’s also a vulnerable point. The electronic control board is placed inside the box and is exposed to hot gear oil influence, because of overheating and pollution, the speed sensors fail. This problem occurs in the same way as in the 5-speed transmission 722.6, and in the 7-mortar 722.9.

The first signs of sensor failure - gear shift deteriorates. There are jerks, or vice versa slipping. Further developments - Check Engine signal appears on the dashboard, the box can start working in emergency mode, or the movement will be completely impossible.

Diagnostics gives the following errors:

• P0793 (ошибка 0793) — The rpm signal from component Y3/9b4 (CVT (continuously variable automatic transmission) secondary rpm sensor) is not available. 
• P0722 (ошибка 0722) — The rpm signal from component Y3/9b5 (CVT (continuously variable automatic transmission) output rpm sensor) is not available.

The solution to the problem is to replace the speed sensors with new ones.:

• Driven pulley rpm sensor (y3/9b4) CVT 722.8 Mercedes
• Output shaft rpm sensor (y3/9b5) CVT 722.8 Mercedes

You can purchase sensors and replace them yourself, or send your board to Maktrans and our masters will repair it.

Repair is as follows:

The master disassembles the board and removes the solder from the back of the sensors.

We bend back the tracks and extract the faulty sensors.

Insert new sensors and solder

Result

Board recovery is completed. An important point - since the board failed due to dirty hot oil - we change the filter, oil, and we strongly recommend installing additional cooling.