ABS: Overview Subaru Outback BP

OPERATION

1. Under the ABS sequence control, after the hydraulic unit solenoid valve is driven, the operation of the hydraulic unit can be checked by means of the brake tester or pressure gauge.
2. ABS sequence control can be started by diagnosis connector or select monitor.

Scheme 3

1. Connect diagnosis terminals to terminals No. 5 and No. 8 of the diagnosis connector beside driver's seat heater unit.
2. Set the speed of all wheels at 2.75 km/h (2 MPH) or less.
3. Turn ignition switch OFF.
4. Immediately after ignition switch is turned ON, depress the brake pedal within 0.5 seconds after the ABS warning light goes out, and hold the brake pedal. CAUTION: Do not depress the clutch pedal. NOTE: When the ignition switch is set to on, the brake pedal must not be depressed. Engine must not operate.
5. After completion of ABS sequence control, turn ignition switch OFF.

Note. In the event of any trouble, the sequence control may not be operative. In such a case, activate the sequence control, referring to "ABS SEQUENCE CONTROL WITH DIAGNOSIS CONNECTOR". Refer to ABS SEQUENCE CONTROL WITH DIAGNOSIS CONNECTOR, OPERATION, ABS SEQUENCE CONTROL . When the diagnosis terminal is connected to the diagnosis connector, the sequence control will not operate.

1. Connect select monitor to data link connector under driver's seat instrument panel lower cover.
2. Turn ignition switch ON.
3. Turn select monitor switch ON.
4. Put select monitor to "BRAKE CONTROL" mode.
5. When "Function check sequence" is selected, ABS sequence control' will start.
6. The message `Press Brake Pedal Firmly' is displayed as follows: When using the brake tester, depress brake pedal with braking force of 981 N (100 kgf, 221 lb). When using the pressure gauge, depress brake pedal so as to make the pressure gauge indicate 3,432 kPa (35 kg/cm 2 , 498 psi). CAUTION: Do not depress the clutch pedal.
7. When the message "Press YES" is displayed, press << YES >> key.
8. Operation points will be displayed on select monitor.

Scheme 4

Note. When select monitor is used, control operation starts at point A. The patterns from IGN key ON to the point A show that operation is started by diagnosis connector. HIGH means high voltage. LOW means low voltage.

When the following conditions develop, the ABS sequence control stops and ABS operation is returned to the normal control mode.

1. When the speed of at least one wheel reaches 10 km/h (6 MPH).
2. When terminal No. 5 or No. 8 are separated from diagnosis terminals. (When select monitor is not used.)
3. When the brake pedal is released during sequence control and the braking lamp switch is set to off.
4. When brake pedal is depressed after ignition key is turned to ON, and before ABS warning light goes out. (When select monitor is not used.)
5. When brake pedal is not depressed after ignition key is turned to ON, and within 0.5 seconds after ABS warning light goes out. (When select monitor is not used.)
6. After completion of the sequence control.
7. When malfunction is detected. (When select monitor is used.)

Scheme 5

Scheme 6

Scheme 7

1. Disconnect ground cable from battery.
2. Disconnect front ABS sensor connector located next to front strut mounting house in engine compartment.
3. Remove bolts which secure sensor harness to strut.
4. Remove bolts which secure sensor harness to body.
5. Remove bolts which secure front ABS sensor to housing, and remove front ABS sensor. CAUTION: Be careful not to damage pole piece located at tip of the sensor and teeth faces during removal. Do not pull sensor harness during removal.

Scheme 8

Scheme 9

Scheme 10

Scheme 11

1. Temporarily install front ABS sensor on housing. CAUTION: Be careful not to strike ABS sensor's pole piece and tone wheel's teeth against adjacent metal parts during installation.
2. Install front ABS sensor on strut and wheel apron bracket. Tightening torque: 33 N.m (3.4 kgf-m, 24 ft-lb)
3. Place a thickness gauge between ABS sensor's pole piece and tone wheel's tooth face. After standard clearance is obtained over the entire perimeter, tighten ABS sensor on housing to specified torque. ABS sensor standard clearance: 0.3 - 0.8 mm (0.012 - 0.31 in) Tightening torque: 32 N.m (3.3 kgf-m, 24 ft-lb) CAUTION: Check the marks on the harness to make sure that no distortion exists. NOTE: If the clearance is outside specifications, adjust the gap using spacer (Part No. 26755AA000).
4. After confirmation of the ABS sensor clearance, connect connector to ABS sensor.
5. Connect connector to battery ground cable.

Scheme 12

Scheme 13

1. Check pole piece of ABS sensor for foreign particles or damage. If necessary, clean pole piece or replace ABS sensor.
2. Measure ABS sensor resistance. CAUTION: If resistance is outside the standard value, replace ABS sensor with new one. NOTE: Check ABS sensor cable for discontinuity. If necessary, replace with a new one.

Scheme 14

Scheme 15

1. Measure the distance "A" between ABS sensor surface and sensor pole face.
2. Measure the distance "B" between surface where the front axle housing meets the ABS sensor, and the tone wheel. NOTE: Measure so that the gauge touches the tone wheel teeth top.
3. Find the gap between the ABS sensor pole face and the surface of the tone wheel teeth by putting the measured valves in the formula below and calculating. ABS sensor clearance = B - A ABS sensor standard clearance: 0.3 - 0.8 mm (0.012 - 0.031 in) NOTE: If the clearance is outside specifications, adjust the gap using spacer (Part No. 26755AA000).