Subaru Legacy 2002 Service Manual page 2606

DIAGNOSTICS CHART WITH SELECT MONITOR
No.
11 CHECK ABS SENSOR SIGNAL.
1) Raise all four wheels of ground.
2) Turn ignition switch OFF.
3) Remove VDCCM connector cover. <Ref. to
VDC-17, VDCCM Connector Cover.>
4) Connect the oscilloscope to the connector.
5) Turn ignition switch ON.
6) Rotate wheels and measure voltage at
specified frequency.
NOTE:
When this inspection is completed, the
VDCCM sometimes stores the DTC 29.
Connector & terminal
DTC 22 / (F87) No. 14 (+) — No. 15 (−):
DTC 24 / (F87) No. 49 (+) — No. 19 (−):
DTC 26 / (F87) No. 18 (+) — No. 46 (−):
DTC 28 / (F87) No. 16 (+) — No. 17 (−):
12 CHECK CONTAMINATION OF ABS SEN-
SOR OR TONE WHEEL.
Remove disc rotor from hub in accordance
with diagnostic trouble code.
13 CHECK DAMAGE OF ABS SENSOR OR
TONE WHEEL.
14 CHECK TONE WHEEL RUNOUT.
Measure tone wheel runout.
15 CHECK RESISTANCE OF ABS SENSOR.
1) Turn ignition switch OFF.
2) Disconnect connector from ABS sensor.
3) Measure resistance between ABS sensor
connector terminals.
Terminal
Front RH No. 1 — No. 2:
Front LH No. 1 — No. 2:
Rear RH No. 1 — No. 2:
Rear LH No. 1 — No. 2:
16 CHECK GROUND SHORT OF ABS SEN-
SOR.
Measure resistance between ABS sensor and
chassis ground.
Terminal
Front RH No. 1 — Chassis ground:
Front LH No. 1 — Chassis ground:
Rear RH No. 1 — Chassis ground:
Rear LH No. 1 — Chassis ground:
Step
Is oscilloscope pattern
smooth, as shown in fig-
ure?
Is the ABS sensor pole
piece or the tone wheel
contaminated by dirt or
other foreign matter?
Are there broken or dam-
aged in the ABS sensor
pole piece or the tone
wheel?
Is the runout less than 0.05
mm (0.0020 in)?
Is the resistance between
1.0 and 1.5 kΩ?
Is the resistance more than
1 MΩ?
VDC-147
Check Yes
Go to step 15.
Thoroughly
remove dirt or
other foreign mat-
ter.
Replace ABS sen-
sor or tone wheel.
Front <Ref. to
VDC-28, Front
ABS Sensor.> and
<Ref. to VDC-30,
Front Tone
Wheel.> Rear
<Ref. to VDC-29,
Rear ABS Sen-
sor.> and <Ref. to
VDC-31, Rear
Tone Wheel.>
Go to step 15.
Go to step 16.
Go to step 17.
VDC (Diagnostics)
No
Go to step 12.
Go to step 13.
Go to step 14.
Repair tone
wheel. Front <Ref.
to VDC-30, Front
Tone Wheel.>
Rear <Ref. to
VDC-31, Rear
Tone Wheel.>
Replace ABS sen-
sor. Front <Ref. to
VDC-28, Front
ABS Sensor.>
Rear <Ref. to
VDC-29, Rear
ABS Sensor.>
Replace ABS sen-
sor. Front <Ref. to
VDC-28, Front
ABS Sensor.>
Rear <Ref. to
VDC-29, Rear
ABS Sensor.>