Subaru IMPREZA 2001 - Page 51

ABS-50
ABS (DIAGNOSTICS)
DIAGNOSTICS CHART WITH DIAGNOSIS CONNECTOR
Step Check Yes No
1 CHECK INSTALLATION OF ABS SENSOR.
Turn ignition switch to OFF.
Tightening torque:
32
±
±±
± 10 N·m (3.3 ±
±±
± 1.0 kgf-m, 24 ±
±±
± 7 ft-lb)
Are the ABS sensor installation
bolts tightened securely?
Go to step
2.
Tighten ABS sen-
sor installation
bolts securely.
2 CHECK ABS SENSOR GAP.
Measure tone wheel to ABS sensor piece gap
over entire perimeter of the wheel.
Front wheel
0.3 — 0.8 mm (0.012 — 0.031 in)
Rear wheel
0.7 — 1.2 mm (0.028 — 0.047 in)
Is the gap within the specifica-
tions?
Go to step
3.
Adjust the gap.
NOTE:
Adjust the gap us-
ing spacer (Part
No. 26755AA000).
If spacers cannot
correct the gap, re-
place worn sensor
or worn tone
wheel.
3 PREPARE OSCILLOSCOPE.
Is an oscilloscope available? Go to step
4.
Go to step
5.
4 CHECK ABS SENSOR SIGNAL.
1)Raise all four wheels of ground.
2)Turn ignition switch OFF.
3)Connect the oscilloscope to the connector.
4)Turn ignition switch ON.
5)Rotate wheels and measure voltage at spec-
ified frequency. <Ref. to ABS-17, WAVE-
FORM, Control Module I/O Signal.>
NOTE:
When this inspection is completed, the ABS
control module sometimes stores the trouble
code 29.
Connector & terminal
Trouble code 22 /
(F95) No. 1 (+) — No. 2 ( −
−−
− ):
Trouble code 24 /
(F94) No. 1 (+) — No. 2 ( −
−−
− ):
Trouble code 26 /
LHD: (B99) No. 9 (+) — No. 10 ( −
−−
− ):
RHD: (B99) No. 20 (+) — No. 21 ( −
−−
− ):
Trouble code 28 /
LHD: (B99) No. 4 (+) — No. 5 ( −
−−
− ):
RHD: (B99) No. 8 (+) — No. 9 ( −
−−
− ):
Is oscilloscope pattern smooth,
as shown in figure?
Go to step
8.
Go to step
7.
5 CHECK CONTAMINATION OF ABS SENSOR
OR TONE WHEEL.
Remove disc rotor or drum from hub in accor-
dance with trouble code.
Is the ABS sensor piece or the
tone wheel contaminated by
dirt or other foreign matter?
Thoroughly
remove dirt or
other foreign mat-
ter.
Go to step
6.
6 CHECK DAMAGE OF ABS SENSOR OR
TONE WHEEL.
Are there broken or damaged
in the ABS sensor piece or the
tone wheel?
Replace ABS sen-
sor or tone wheel.
Front: <Ref. to
ABS-14, Front
ABS Sensor.>
Rear: <Ref. to
ABS-17, Rear
ABS Sensor.> and
Front: <Ref. to
ABS-20, Front
Tone Wheel.>
Rear: <Ref. to
ABS-21, Rear
Tone Wheel.>
Go to step
7.