General Notes

ABS/EDL and ABS/EDL/ASR ITT Mark 20 IE

ABS prevents wheels from locking during a driver - induced brake procedure.

The Electronic Differential Lock (EDL), is a start - up aid when driving away from a stand still. An electronically controlled brake application on the spinning (slipping) wheel provides a torque reaction point for the differential. Torque is therefore applied to the wheel with traction. EDL is effective in both forward and reverse directions. The EDL controls are implemented up to a speed of 80 km/h.

The brake system is divided diagonally. Brake boost is applied pneumatically through the vacuum brake booster.

Vehicles with ITT Mark 20 IE ABS or ABS/EDL/ATC have no mechanical brake pressure regulator. A special software in the control module takes over the variation of brake force to the rear axle with electronic brake distribution (EBV).

The hydraulic pump - V64, hydraulic control module -N55- and control module - J104 make up the "hydraulic control unit." Repair is possible only when this is removed,

New control modules from the Parts Supplier are not coded. They are coded after installation.





ITT Mark 20 IE ABS/EDL or ABS/EDL/ATC
^ Dimension a = 130 mm

^ 10 valve dome: protective sleeves for valves are visible when control module is separated from hydraulic unit, refer to Hydraulic Control Unit Servicing.

During function activating control module VAG1551 Display shows: "8N0 907 379 A ABS/EDL 20 IE" (for quattro) or "8N0 907 379 ATC 20 IE."