Subaru Impreza 2002 Service Manual page 510

DIAGNOSTICS CHART WITH DIAGNOSIS CONNECTOR
Step
2 CHECK SPECIFICATIONS OF ABSCM&H/U.
Check the specifications mark on ABSCM&
H/U.
CM: AT (Rear disc brake)
CN: MT (Rear disc brake)
CC: AT (Rear drum brake)
CD: MT (Rear drum brake)
C9: MT (STi model)
3 CHECK INPUT VOLTAGE OF G SENSOR.
1)Turn the ignition switch to OFF.
2)Remove the console box.
3)Remove the G sensor from vehicle. (Do not
disconnect the connector.)
4)Turn the ignition switch to ON.
5)Measure the voltage between G sensor con-
nector terminals.
Connector & terminal
(B292) No. 1 (+) — No. 3 ( − − − − ):
4 CHECK OPEN CIRCUIT IN G SENSOR OUT-
PUT HARNESS AND GROUND HARNESS.
1)Turn the ignition switch to OFF.
2)Disconnect the connector from ABSCM&
H/U.
3)Measure the resistance between
ABSCM&H/U connector terminals.
Connector & terminal
LHD: (B301) No. 6 — No. 28:
RHD: (F49) No. 6 — No. 28:
5 CHECK GROUND SHORT IN G SENSOR
OUTPUT HARNESS.
1)Disconnect the connector from G sensor.
2)Measure the resistance between
ABSCM&H/U connector and chassis ground.
Connector & terminal
LHD: (B301) No. 6 — Chassis ground:
RHD: (F49) No. 6 — Chassis ground:
6 CHECK BATTERY SHORT OF HARNESS.
Measure the voltage between ABSCM&H/U
connector and chassis ground.
Connector & terminal
LHD: (B301) No. 6 (+) — Chassis ground
( − − − − ):
RHD: (F49) No. 6 (+) — Chassis ground
( − − − − ):
7 CHECK BATTERY SHORT OF HARNESS.
1)Turn the ignition switch to ON.
2)Measure the voltage between ABSCM&H/U
connector and chassis ground.
Connector & terminal
LHD: (B301) No. 6 (+) — Chassis ground
( − − − − ):
RHD: (F49) No. 6 (+) — Chassis ground
( − − − − ):
Check
Does the vehicle specification
and ABSCM&H/U specifica-
tion match?
Is the voltage between 4.75
and 5.25 V?
Is the resistance between 5.0
and 5.6 kΩ?
Is the resistance more than 1
MΩ?
Is the voltage less than 1 V?
Is the voltage less than 1 V?
ABS-13
ABS (DIAGNOSTICS)
Yes
Go to step 3. Replace the
ABSCM&H/U.
<Ref. to ABS-4,
ABS Control Mod-
ule and Hydraulic
Control Unit
(ABSCM&H/U).>
CAUTION:
Be sure to turn
the ignition
switch to OFF
when removing
ABSCM&H/U.
Go to step 4. Repair the har-
ness/connector
between G sensor
and ABSCM&H/U.
Go to step 5. Repair the har-
ness/connector
between G sensor
and ABSCM&H/U.
Go to step 6. Repair the har-
ness between G
sensor and
ABSCM&H/U.
Go to step 7. Repair the har-
ness between G
sensor and
ABSCM&H/U.
Go to step 8. Repair the har-
ness between G
sensor and
ABSCM&H/U.
No