Subaru Impreza 2003 Service Manual page 2387

DIAGNOSTICS PROCEDURE WITHOUT DIAGNOSTIC TROUBLE CODE (DTC)
Step
1 CHECK ABS WHEEL SPEED SENSOR.
1)Turn the ignition switch to OFF.
2)Disconnect the connector from ABS wheel
speed sensor.
3)Measure the resistance of ABS wheel speed
sensor connector terminals while shaking the
harness lightly.
Terminals
Front RH No. 1 — No. 2:
Front LH No. 1 — No. 2:
Rear RH No. 1 — No. 2:
Rear LH No. 1 — No. 2:
2 CHECK BATTERY SHORT OF ABS WHEEL
SPEED SENSOR.
1)Disconnect the connector from ABSCM&
H/U.
2)Measure the voltage 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 ( − − − − ):
3 CHECK BATTERY SHORT OF ABS WHEEL
SPEED SENSOR.
1)Turn the ignition switch to ON.
2)Measure the voltage 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 ( − − − − ):
4 CHECK HARNESS/CONNECTOR BETWEEN
ABSCM&H/U AND ABS WHEEL SPEED
SENSOR.
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 terminals.
Connector & terminal
DTC 21
LHD: (B301) No. 11 — No. 12:
RHD: (F49) No. 11 — No. 12:
DTC 23
LHD:(B301) No. 9 — No. 10:
RHD: (F49) No. 9 — No. 10:
DTC 25
LHD:(B301) No. 14 — No. 15:
RHD: (F49) No. 14 — No. 15:
DTC 27
LHD:(B301) No. 7 — No. 8:
RHD: (F49) No. 7 — No. 8:
Check
Is the resistance as following
value?
Front: 1 — 1.5 kΩ
Rear: 1.025 — 1.265 kΩ
Is the voltage less than 1 V?
Is the voltage less than 1 V?
Is the resistance as following
value?
Front: 1 — 1.5 kΩ
Rear: 1.025 — 1.265 kΩ
ABS-47
ABS (DIAGNOSTICS)
Yes
Go to step 2. Replace the ABS
wheel speed sen-
sor. Front: <Ref. to
ABS-13, Front
ABS Wheel Speed
Sensor.> Rear:
<Ref. to ABS-16,
Rear ABS Wheel
Speed Sensor.>
Go to step 3. Replace the ABS
wheel speed sen-
sor. Front: <Ref. to
ABS-13, Front
ABS Wheel Speed
Sensor.> Rear:
<Ref. to ABS-16,
Rear ABS Wheel
Speed Sensor.>
Go to step 4. Replace the ABS
wheel speed sen-
sor. Front: <Ref. to
ABS-13, Front
ABS Wheel Speed
Sensor.> Rear:
<Ref. to ABS-16,
Rear ABS Wheel
Speed Sensor.>
Go to step 5. Repair the har-
ness/connector
between
ABSCM&H/U and
ABS wheel speed
sensor.
No