SUBARU LEGACY 1996 Service Repair Manual

10AK7
CHECK ABSCM.
1) Connect all connectors.
2) Erase the memory.
3) Perform inspection mode.
4) Read out the trouble code.
: Is the same trouble code as in the current
diagnosis still being output?
: Replace ABSCM.
: Go to next.
: Are other trouble codes being output?
: Proceed with the diagnosis corresponding to the
trouble code.
: A temporary poor contact.
271
4-4cBRAKES [ABS 5.3 TYPE]
10. Diagnostics Chart with Select Monitor

11. General Diagnostics Table
A: SYMPTOMS AND PROBABLE CAUSES
Symptom Probable faulty units/parts
Vehicle instability during brakingVehicle pulls to either side.
Hydraulic unit (solenoid valve)

ABS sensor

Brake (caliper & piston, pads)

Wheel alignment

Tire specifications, tire wear and air pressures

Incorrect wiring or piping connections

Road surface (uneven, camber)
Vehicle spins.
Hydraulic unit (solenoid valve)

ABS sensor

Brake (pads)

Tire specifications, tire wear and air pressures

Incorrect wiring or piping connections
Poor brakingLong braking/stopping distance
Hydraulic unit (solenoid valve)

Brake (pads)

Air in brake line

Tire specifications, tire wear and air pressures

Incorrect wiring or piping connections
Wheel locks.
Hydraulic unit (solenoid valve, motor)

ABS sensor

Incorrect wiring or piping connections
Brake dragging
Hydraulic unit (solenoid valve)

ABS sensor

Master cylinder

Brake (caliper & piston)

Parking brake

Axle & wheels

Brake pedal play
Long brake pedal stroke
Air in brake line

Brake pedal play
Vehicle pitching
Suspension play or fatigue (reduced damping)

Incorrect wiring or piping connections

Road surface (uneven)
Unstable or uneven braking
Hydraulic unit (solenoid valve)

ABS sensor

Brake (caliper & piston, pads)

Tire specifications, tire wear and air pressures

Incorrect wiring or piping connections

Road surface (uneven)
Vibration and/or noise (while
driving on slippery roads)Excessive pedal vibration
Incorrect wiring or piping connections

Road surface (uneven)
Noise from hydraulic unit
Hydraulic unit (mount bushing)

ABS sensor

Brake piping
Noise from front of vehicle
Hydraulic unit (mount bushing)

ABS sensor

Master cylinder

Brake (caliper & piston, pads, rotor)

Brake piping

Brake booster & check valve

Suspension play or fatigue
Noise from rear of vehicle
ABS sensor

Brake (caliper & piston, pads, rotor)

Parking brake

Brake piping

Suspension play or fatigue
272
4-4cBRAKES [ABS 5.3 TYPE]
11. General Diagnostics Table

B: CHECKING THE HYDRAULIC UNIT
OPERATION

1) Do ABS sequence control patterns take place in correct
order?
If not, check wiring and piping for incorrect connections.
2) Are oil pressure or braking force variations within speci-
fications?
If not, check master cylinder, brake piping, hydraulic unit,
proportioning valve and wheel cylinder for improper opera-
tion.
3) Does pedal hardness change before and after ABS
sequence control?
If so, bleed air from brake line.
273
4-4cBRAKES [ABS 5.3 TYPE]
11. General Diagnostics Table

1. Electrical Components Location
B5M0395A
Connector No. (AB1) (AB2) (AB3) (AB4) (AB5) (AB6) (AB7) (AB8) (AB9) (AB10)
Pole73322123333
Color Yellow Yellow Yellow Blue Orange Yellow Yellow Yellow Yellow Yellow
Male/Female Male Female Female Female Female Female Male Male Male Female
2
5-5SUPPLEMENTAL RESTRAINT SYSTEM
1. Electrical Components Location

2. Schematic
B5M0111B
3
5-5SUPPLEMENTAL RESTRAINT SYSTEM
2. Schematic

3. Tools for Diagnostics
CAUTION:
Be sure to use specified test harness A, B or C when
measuring voltage, resistance, etc. of AIRBAG system
component parts.
A: TEST HARNESS A
B5M0112A
4
5-5SUPPLEMENTAL RESTRAINT SYSTEM
3. Tools for Diagnostics

B: TEST HARNESS B2
G5M0593
5
5-5SUPPLEMENTAL RESTRAINT SYSTEM
3. Tools for Diagnostics

C: TEST HARNESS C
B5M0113A
6
5-5SUPPLEMENTAL RESTRAINT SYSTEM
3. Tools for Diagnostics

D: AIRBAG RESISTOR
The airbag resistor is used during diagnostics. The airbag
resistor has the same resistance as the airbag module and
thus provides safety when used instead of the airbag mod-
ule. It also makes it possible to finish, diagnostics in less
time.
B5M0114A
7
5-5SUPPLEMENTAL RESTRAINT SYSTEM
3. Tools for Diagnostics

4. Diagnostics Chart for On-board
Diagnostic System
A: BASIC DIAGNOSTICS PROCEDURE
8
5-5SUPPLEMENTAL RESTRAINT SYSTEM
4. Diagnostics Chart for On-board Diagnostic System