General Description - Subaru Legacy Service Manual

ABS (DIAGNOSTICS)

3. General Description

A: CAUTION
1. SUPPLEMENTAL RESTRAINT SYSTEM
"AIRBAG"
Airbag system wiring harness is routed near the
ABS wheel speed sensor and ABSCM&H/U.
CAUTION:
• All airbag system wiring harness and con-
nectors are colored yellow. Do not use the elec-
trical test equipment on these circuits.
• Be careful not to damage the airbag system
wiring harness when servicing the ABS wheel
speed sensor and ABSCM&H/U.
B: INSPECTION
Before performing diagnosis, check the following
items which might affect ABS problems.
1. BATTERY
Measure battery voltage and check electrolyte.
Standard voltage: 12 V or more
Specific gravity: More than 1.260
2. BRAKE FLUID
1) Check the brake fluid level.
2) Check the brake fluid for leaks.
3. HYDRAULIC UNIT
Check the hydraulic unit.
• With brake tester <Ref. to ABS-8, CHECKING
THE HYDRAULIC UNIT ABS OPERATION WITH
BRAKE TESTER, INSPECTION, ABS Control
Module and Hydraulic Control Unit (ABSCM&H/
U).>
• Without brake tester <Ref. to ABS-7, CHECK-
ING THE HYDRAULIC UNIT ABS OPERATION
BY PRESSURE GAUGE, INSPECTION, ABS
Control Module and Hydraulic Control Unit (AB-
SCM&H/U).>
4. BRAKE DRAG
Check for brake drag.
5. BRAKE PAD AND ROTOR
Check the brake pad and rotor.
• FRONT <Ref. to BR-18, INSPECTION, Front
Brake Pad.> <Ref. to BR-19, INSPECTION, Front
Disc Rotor.>
• REAR <Ref. to BR-25, INSPECTION, Rear
Brake Pad.> <Ref. to BR-26, INSPECTION, Rear
Disc Rotor.>
General Description
6. TIRE
Check the tire specifications, tire wear and air pres-
sure. <Ref. to WT-2, SPECIFICATION, General
Description.>
ABS(diag)-8