Anti-Lock Braking System - Diagnostics: Overview Subaru Forester SF рестайлинг

Checking The Hydraulic Unit Operation

1. 11B1: PREPARING THE BRAKE TESTER. CHECK: Is the brake tester available? YES: Check operation with brake tester. See «CHECKING HYDRAULIC UNIT ABS OPERATION WITH BRAKE TESTER»(ref-175571-S17275048712005050600000) . NO: Check operation by pressure gauge. See «CHECKING HYDRAULIC UNIT ABS OPERATION BY PRESSURE GAUGE»(ref-175571-S32950160332005050600000) .

Identifying ABS Control Module & Hydraulic Control Unit (ABSCM & H/U). Scheme 16

Tightening torque: N.m (kg-m, ft-lb)

1. T1: 18+/-5 (1.8+/-0.5, 13.0+/-3.6)
2. T2: 29+/-7 (3.0+/-0.7, 21.7+/-5.1)
3. T3: 32+/-10 (3.3+/-1.0, 24+/-7)

Scheme 17

Scheme 18

1. Disconnect ground cable from battery.
2. Remove air intake duct from engine compartment to facilitate removal of ABSCM & H/U.
3. Use an air gun to get rid of water around the ABSCM & H/U. CAUTION: The contact will be insufficient if the terminal gets wet.
4. Pull on the lock of the ABSCM & H/U connector to remove it. (Scheme 17): Identifying Lock On ABSCM & H/U Connector
5. Disconnect connector from ABSCM & H/U. CAUTION: Be careful not to let water or other foreign mater contact the ABSCM & H/U terminal.
6. Unlock cable clip.
7. Disconnect brake pipes from ABSCM & H/U. CAUTION: Wrap brake pipes with vinyl bag to avoid spilling brake fluid on vehicle body.
8. Remove ABSCM & H/U from engine compartment. CAUTION: ABSCM & H/U cannot be disassembled. Do not attempt to loosen bolts and nuts. Do not drop or bump ABSCM & H/U. Do not turn the ABSCM & H/U upside down or place it on its side. Be careful to prevent foreign particles from getting into ABSCM & H/U. Apply a coat of rust-preventive wax (Nippeco LT or GB) to bracket attaching bolt after tightening. Do not pull harness disconnecting harness connector. (Scheme 18): Apply Coat Of Rust-Preventive Wax To Bracket Attaching Bolts

Scheme 19

Scheme 20

1. Check connected and fixed condition of connector.
2. Check specifications of the mark with ABSCM & H/U. (Scheme 19): Identifying Mark On ABSCM & H/U (Scheme 20): Specifications On mark On ABSCM & H/U

Scheme 21

Scheme 22

1. Lift-up vehicle and remove wheels.
2. Disconnect the air bleeder screws from the FL and FR caliper bodies.
3. Connect the two pressure gauges to the FL and FR caliper bodies. CAUTION: Pressure gauges used exclusively for brake fluid must be used. Do not employ pressure gauge previously used for transmission since the piston seal is expanded which may lead to malfunction of the brake. NOTE: Wrap sealing tape around the pressure gauge. (Scheme 21): Installing Pressure gauges (Use Gauges Exclusively For Use With Brake Fluid)
4. Bleed air from the pressure gauges.
5. Perform ABS sequence control, see «ABS SEQUENCE CONTROL»(ref-175571-S02322781852005050600000).
6. When the hydraulic unit begins to work, first the FL side performs decompression, holding, and compressing; and then the FR side performs decompression, holding, and compressing.
7. Read values indicated on the pressure gauge and check if the fluctuation of the values between decompression and compression meets the standard values. Also check if any irregular brake pedal tightness is felt. (Scheme 22): Brake Decompression & Compression Values Chart
8. Remove pressure gauges from FL and FR caliper bodies.
9. Remove air bleeder screws from the RL and RR caliper bodies.
10. Connect the air bleeder screws to the FL and FR caliper bodies.
11. Connect the two pressure gauges to the RL and RR caliper bodies.
12. Bleed air from the pressure gauges and the FL and FR caliper bodies.
13. Perform ABS sequence control, see «ABS SEQUENCE CONTROL»(ref-175571-S02322781852005050600000).
14. When the hydraulic unit begins to work, first the RR side performs decompression, holding, and compressing; and then the RL side performs decompression, holding, and compressing.
15. Read values indicated on the pressure gauges and check if they meet the standard value.
16. After checking, remove the pressure gauges from caliper bodies.
17. Connect the air bleeder screws to RL and RR caliper bodies.
18. Bleed air from brake line.

Scheme 23

Scheme 24

Scheme 25

1. In the case of AWD AT vehicles, install a spare fuse with the FWD connector in the main fuse box to simulate FWD vehicles. (Scheme 23): Identifying FWD Connector In Main Fuse Box
2. Prepare for operating ABS sequence control, see «CONDITIONS FOR ABS SEQUENCE CONTROL»(ref-175571-S32086005692005050600000).
3. Set the front wheels or rear wheels on the brake tester and set the select lever's position at "neutral". (Scheme 24): Setting Front Wheels Or Rear Wheels On Brake Tester
4. Operate the brake tester.
5. Perform ABS sequence control, see «ABS SEQUENCE CONTROL»(ref-175571-S02322781852005050600000).
6. Hydraulic unit begins to work; and check the following working sequence. The FL wheel performs decompression, holding, and compression in sequence, and subsequently the FR wheel repeats the cycle. The RR wheel performs decompression, holding, and compression in sequence, and subsequently the RL wheel repeats the cycle.
7. Read values indicated on the brake tester and check if the fluctuation of values, when decompressed and compressed, meet the standard values. (Scheme 25): Brake Decompression & Compression Values Chart
8. After checking, also check if any irregular brake pedal tightness is felt.

Operational Guidelines Of The ABS Sequence Control With Select Monitor

Note. In the event of any trouble, the sequence control may not be operative. In such a case, activate the sequence control, see OPERATIONAL GUIDELINES OF THE ABS SEQUENCE CONTROL WITH DIAGNOSIS CONNECTOR . When the diagnosis terminal is connected to the diagnosis connector, the sequence control will not operate.

1. Connect select monitor to data link connector beside driver's seat instrument panel lower cover.
2. Turn ignition switch to ON.
3. Turn select monitor switch to ON.
4. Put select monitor to (ABS/TCS) 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 kg, 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.