Electronic Brake Control Module: Service and Repair

ABS control module and hydraulic unit, removing and installing
Required special tools and equipment:





^ VAG 1331 Torque wrench or equivalent





^ VAG 1410 Torque wrench or equivalent

Additional information:

CAUTION! Before working on any part of the brake system, read CAUTIONS and WARNINGS, Refer to Service Precautions.

Location
The control module is attached to the hydraulic unit and is located on the left side of the engine compartment.

CAUTION! Do not bend brake lines at the hydraulic unit.

Removing
^ Obtain radio code for vehicles with coded radio.
^ Disconnect battery.





^ Remove intake hose -1. and connector -2- from Mass Air Flow (MAF) Sensor.
^ Remove bolts -4- and -5-.
^ Remove air cleaner as complete unit.
^ For vehicles with Diesel engines, remove relay panel above brake booster.

WARNING!
^ Brake fluid is poisonous.
^ To draw off brake fluid from the reservoir use a bleeder bottle used only for brake fluid. Never siphon brake fluid by mouth.

^ Remove as much brake fluid as possible from brake fluid reservoir using a bleeder bottle.
^ Install brake pedal depressor from VAG 1238 B or equivalent.
^ Connect bleeder bottle hose to left front brake caliper bleeder screw and open bleeder screw. Close bleeder screw.





^ Release control module connector (arrow -1-) and disconnect (arrow -2-).
^ Place plastic covering under control module and hydraulic unit. Do not use rags.

CAUTION! Do not let brake fluid enter electrical connectors.





^ Disconnect brake lines from hydraulic unit to brake master cylinder (arrows) and suspend with wire.
^ Disconnect remaining brake lines on hydraulic unit.
^ Seal brake lines and threaded holes (arrows) with plugs from repair kit, Part No. 1H0 698 311 A.





^ Remove bolts on hydraulic unit bracket (arrows).
^ Remove hydraulic unit with control module.

ABS control module, removing from from hydraulic unit
^ Disconnect electrical connector for hydraulic pump motor from control module.





^ Remove bolts (arrows) from control module.





^ Pull control module straight up to remove.

Note:
^ Be sure that the hydraulic unit valve dome is not tilted against the control module solenoid valves.
^ Cover the control module magnetic coils with a plastic covering. Do not use rags.
^ After separating the control module and hydraulic unit, use transportation protection for the valve dome.

Installing

CAUTION!
^ Only remove seating plugs on the new hydraulic unit just before installing the corresponding brake line.
^ If the seating plugs are removed too early, brake fluid can escape. It can then no longer be guaranteed that the unit is sufficiently filled or adequately bled.
^ When assembling the control module and hydraulic unit, be sure that the hydraulic unit valve dome is not tilted against the control module solenoid valves.

^ Using new bolts, install control module to hydraulic unit. Do not tighten more than maximum 4 Nm (35 inch lbs.).
^ Re-connect electrical connector for hydraulic pump motor.
^ Install ABS unit to bracket.

Note: Hand-tighten bolts to make attaching individual brake lines easier.

^ After tightening brake lines, tighten hydraulic unit.
^ Continue installation in reverse order of removal.
^ Bleed brake system go to Brake Bleeding.
^ Enter radio code.
^ Code control module

Tightening torques:
Control Module To Hydraulic Unit Maximum 4 Nm (35 inch lbs.)
Hydraulic Unit Bolt To Bracket 8 Nm (71 inch lbs.)
Nut For Brake Master Cylinder To Brake Booster 20 Nm (15 ft. lbs.)
Brake lines to ABS unit:
Thread M10 x 1 15 Nm (11 ft. lbs.)
Thread M12 x 1 15 Nm (11 ft. lbs.)
Nut To Body 20 Nm (15 ft. lbs.)
Cap Nut To Body 20 Nm (15 ft. lbs.)