Sequence Control

NOTE: For AWD vehicles, install spare fuse in FWD connector in engine compartment behind right side strut tower to simulate FWD vehicle.

Remove front caliper bleeder screws. Connect brake pressure gauges to calipers and bleed system. Connect diagnostic terminals to diagnosis connector terminal No. 1 and No. 2. Set front wheels on brake tester with vehicle in Neutral. Operate brake tester according to manufacturer's instructions. Set wheel speed at 2 MPH (4 km/h) or less. Turn ignition on. ABS warning light should illuminate for 1.5 seconds. Within .5 second after ABS warning light goes out, depress brake pedal. Hydraulic unit should now begin to operate. See Fig 1 .

Fig 1: ABS Sequence Control Chart
Courtesy of SUBARU OF AMERICA, INC.
Observe pressure gauges and note readings. See HYDRAULIC UNIT PRESSURE SPECIFICATIONS table. Hydraulic unit should perform left front decompression, holding and then compression. Hydraulic unit should perform right front decompression, holding and then compression. Turn ignition off. Remove pressure gauges. Bleed system. Repeat test at rear wheels. If pressure readings are not as specified, replace hydraulic unit. See HYDRAULIC UNIT PRESSURE SPECIFICATIONS table.

HYDRAULIC UNIT PRESSURE SPECIFICATIONS