Subaru IMPREZA 2001 - Page 10

ABS-9
ABS (DIAGNOSTICS)
GENERAL DESCRIPTION
3. General Description
A: CAUTION
1. SUPPLEMENTAL RESTRAINT SYSTEM
“AIRBAG”
Airbag system wiring harness is routed near the
ABS sensor, ABS control module and hydraulic
control unit.
CAUTION:
• All Airbag system wiring harness and con-
nectors are colored yellow. Do not use electri-
cal test equipment on these circuit.
• Be careful not to damage Airbag system wir-
ing harness when servicing the ABS sensor,
ABS control module and hydraulic control unit.
B: INSPECTION
Before performing diagnostics, check the following
items which might affect ABS problems:
1. BATTERY
Measure battery voltage and specific gravity of
electrolyte.
Standard voltage: 12 V, or more
Specific gravity: Above 1.260
2. BRAKE FLUID
1) Check brake fluid level.
2) Check brake fluid leakage.
3. HYDRAULIC UNIT
Check the hydraulic unit.
• With brake tester <Ref. to ABS-9, 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-8, 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 brake drag.
5. BRAKE PAD AND ROTOR
Check brake pad and rotor.
• Front <Ref. to BR-24, INSPECTION, Front
Brake Pad.> and <Ref. to BR-27, INSPECTION,
Front Disc Rotor.>
• Rear <Ref. to BR-35, INSPECTION, Rear
Brake Pad.> and <Ref. to BR-38, INSPECTION,
Rear Disc Rotor.> or <Ref. to BR-45, INSPEC-
TION, Rear Drum Brake Shoe.> and <Ref. to BR-
47, INSPECTION, Rear Drum Brake Drum.>
6. TIRE
Check tire specifications, tire wear and air pres-
sure. <Ref. to WT-2, SPECIFICATIONS, General
Description.>