Subaru Impreza 2003 Service Manual page 2389

DIAGNOSTICS PROCEDURE WITHOUT DIAGNOSTIC TROUBLE CODE (DTC)
Step
8 CHECK ABS WHEEL SPEED SENSOR GAP.
Measure the tone wheel to ABS wheel speed
sensor piece gap over entire perimeter of the
wheel.
9 CHECK TONE WHEEL RUNOUT.
Measure the tone wheel runout.
10 CHECK GROUND SHORT OF ABS WHEEL
SPEED SENSOR.
1)Turn the ignition switch to ON.
2)Measure the resistance between ABS wheel
speed sensor and chassis ground.
Terminals
Front RH No. 1 — Chassis ground:
Front LH No. 1 — Chassis ground:
Rear RH No. 1 — Chassis ground:
Rear LH No. 1 — Chassis ground:
11 CHECK GROUND SHORT OF HARNESS.
1)Turn the ignition switch to OFF.
2)Connect the connector to ABS wheel speed
sensor.
3)Measure the resistance between
ABSCM&H/U connector terminal and chassis
ground.
Connector & terminal
DTC 21
LHD: (B301) No. 11 — Chassis ground:
RHD: (F49) No. 11 — Chassis ground:
DTC 23
LHD: (B301) No. 11 — Chassis ground:
RHD: (F49) No. 11 — Chassis ground:
DTC 25
LHD: (B301) No. 14 — Chassis ground:
RHD: (F49) No. 14 — Chassis ground:
DTC 27
LHD: (B301) No. 7 — Chassis ground:
RHD: (F49) No. 7 — Chassis ground:
12 CHECK POOR CONTACT IN CONNECTORS. Is there poor contact in con-
Check
Is the gap as following value?
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 runout less than 0.05
mm (0.0020 in)?
Is the resistance more than 1
MΩ?
Is the resistance more than 1
MΩ?
nectors between ABSCM&H/U
and ABS wheel speed sensor?
ABS-49
ABS (DIAGNOSTICS)
Yes
Go to step 9. Adjust the gap.
NOTE:
Adjust the gap us-
ing spacers (Part
No. 26755AA000).
If the spacers can-
not correct gap, re-
place worn sensor
or worn
wheel.
Go to step 10. Replace the tone
wheel. Front:
<Ref. to ABS-19,
Front Tone
Wheel.> Rear:
<Ref. to ABS-20,
Rear Tone
Wheel.>
Go to step 11. Replace the ABS
wheel speed sen-
sor and
ABSCM&H/U.
Front: <Ref. to
ABS-13, Front
ABS Wheel Speed
Sensor.> Rear:
<Ref. to ABS-16,
Rear ABS Wheel
Speed Sensor.>
and <Ref. to ABS-
7, ABS Control
Module and
Hydraulic Control
Unit (ABSCM&H/
U).>
Go to step 12. Repair the har-
ness between
ABSCM&H/U and
ABS wheel speed
sensor.
Replace the
ABSCM&H/U.
<Ref. to ABS-7,
ABS Control Mod-
ule and Hydraulic
Control Unit
(ABSCM&H/U).>
Repair the con- Go to step 13.
nector.
No
tone