In this article and video we will be removing the valve body on the 7G transmission. See how to remove it for rebuild, repair or replacement. See parts 2 – 4 for the remainder of the procedure.
Mercedes-Benz 722.9 transmissions, also known as the 7G tronic, have been in production from model year 2003 to present. This 7 forward speed transmission with 2 reverse gears has been known to have some common problems that require servicing of the internal, valve body and ECU electrics plate. Please be aware that the ECU plate is a theft deterrent part on vehicles fitted with this 7G transmission, and a locksmith license (LSID) will be required when purchasing Theft Relevant Parts (TRP). When a fault occurs in the ECU electronics plate also known as a conductor plate, fault codes for the Turbine Speed Sensor may be present along with symptoms like; improper shifting, Limp Home Mode all accompanied by a malfunction indicator lamp (MIL). For a complete description and list of possible fault codes please refer to our help document or contact support.
- 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.
Begin by draining the transmission fluid. Remove the drain plug and let drain completely.
Once the fluid begins to trickle out, you can drain the remaining fluid in the pan by removing the fluid level tube. Use a drift or punch to push it up and into transmission pan. It will pop off the pan when pushed up. The remaining fluid will drain.
Reinstall transmission pan drain plug and install it finger tight.
Working at the right side of the transmission bell housing, remove the E10 Torx fastener. Then, remove the heatshield.
Disconnect the transmission ECU electrical connector by pressing the release tab while pulling the connector straight off.
Working at the left side of the transmission, remove the E12 Torx electrical harness support bracket fastener. Then, pull the bracket down and away from the transmission.
Disconnect the four oxygen sensor electrical connectors by pressing the release tab while pulling the connector straight off. We suggest labeling the connectors to avoid mixing them up when reconnecting.
Working at the left side of the transmission, disconnect the intelligent shift module (ISM) electrical connector by sliding the red locking tab down and then, pressing the release tab while pulling the connector straight off.
Detach the wiring harness from the mounting bracket, then remove the mounting bracket.
Remove the six E40 Torx transmission pan fasteners and discard, these will be replaced with new. Save the pan gasket clips, they will be reused. Support the pan as you remove the final fastener and remove the pan from transmission.
Remove the transmission filter by pulling it straight down. This will be replaced with a new filter.
Working at the valve body, remove the ten T30 TX Torx valve body aluminum fasteners and discard, these will be replaced with new.
Support the valve body as you remove the final few fasteners. If stuck, press down on electrical connector at right side of transmission to release the valve body from transmission.
Lower and remove the valve body.
Note the orientation of the transfer tube for reinstallation. It will be transferred over to the new valve body.
Also note the transmission range selector position for reinstallation.
That ends Step 1. In Step 2 we will begin with removing the ECU electrics plate from the valve body.
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