Subaru Impreza 2003, Service Manual

Page: 2451 / 3610

ABS-111
ABS (DIAGNOSTICS)
DIAGNOSTICS PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
15 CHECK ABS WHEEL SPEED SENSOR GAP.
Measure the tone wheel to ABS wheel speed
sensor piece gap over entire perimeter of the
wheel.
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) Go to step 16. 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 tone
wheel.
16 CHECK TONE WHEEL RUNOUT.
Measure the tone wheel runout.
Is the runout less than 0.05
mm (0.0020 in)? Go to step 17. Replace the tone
wheel. Front:
<Ref. to ABS-19,
Front Tone
Wheel.> Rear:
<Ref. to ABS-20,
Rear Tone
Wheel.>
17 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:
Is the resistance more than 1
M
Ω
?
Go to step 18. 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).>
18 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. 9 — Chassis ground:
RHD: (F49) No. 9 — 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:
Is the resistance more than 1
M
Ω
?
Go to step 19. Repair the har-
ness between
ABSCM&H/U and
ABS wheel speed
sensor.
And replace the
ABSCM&H/U.
<Ref. to ABS-7,
ABS Control Mod-
ule and Hydraulic
Control Unit
(ABSCM&H/U).>
19 CHECK POOR CONTACT IN CONNECTORS. Is there poor contact in con-
nectors between ABSCM&H/U
and ABS wheel speed sensor? Repair the con-
nector. Go to step 20.
Step Check Yes No