Mercedes CL-Class 722.9 Transmission Control Unit (VGS) / Conductor Plate Repair

The Mercedes CL-Class 7G-Tronic (722.9) gearbox control module — also known as the VGS or conductor plate — is a common source of transmission-related issues and limp mode activation.
When this module fails, CL-Class drivers may experience harsh or delayed gear changes, loss of gear selection, or the gearbox becoming stuck in one gear.

During diagnostic scans, the following fault codes are often stored in the transmission system:

• P0721 – Output Speed Sensor (Y3/8n3) signal faulty or out of range

• P0717 – Turbine Speed Sensor (Y3/8n1) signal not available

• P0722 – Output Speed Sensor (Y3/8n3) signal missing

• P2767 – Internal Speed Sensor (Y3/8n2) signal not available

These codes typically indicate internal electrical faults within the VGS module itself. The unit continuously monitors gearbox input, output, and internal speed sensors to manage smooth gear engagement — so any signal loss can immediately trigger transmission faults or limp mode.

⚠️ Important Shipping Notice:
If you are sending your Mercedes CL-Class 7G-Tronic gearbox control unit to VCUS for testing or repair, please send only the plastic electronic module (VGS/conductor plate).
Do not send the metal valve body or valve chest assembly, as this can cause damage to the module during transit.