Subaru Legacy 2002 Service Manual page 2449

DIAGNOSTICS CHART WITH SUBARU SELECT MONITOR
ABS (Diagnostics)
No.
12 CHECK BATTERY SHORT OF HARNESS.
1) Turn ignition switch to ON.
2) Measure voltage between ABSCM&H/U
connector and chassis ground.
Connector & terminal
(F49) No. 6 (+) — Chassis ground (−):
13 CHECK POOR CONTACT IN CONNEC-
TORS.
14 CHECK ABSCM&H/U.
1) Connect all connectors.
2) Erase the memory.
3) Perform inspection mode.
4) Read out the DTC.
15 CHECK ANY OTHER DTC APPEARANCE.
16 CHECK INPUT VOLTAGE OF G SENSOR.
1) Turn ignition switch to OFF.
2) Remove console box.
3) Disconnect G sensor from body. (Do not
disconnect connector.)
4) Turn ignition switch to ON.
5) Measure voltage between G sensor con-
nector terminals.
Connector & terminal
(R70) No. 1 (+) — No. 3 (−):
17 CHECK OPEN CIRCUIT IN G SENSOR OUT-
PUT HARNESS AND GROUND HARNESS.
1) Turn ignition switch to OFF.
2) Disconnect connector from ABSCM&H/U.
3) Measure resistance between ABSCM&H/U
connector terminals.
Connector & terminal
(F49) No. 6 — No. 28:
18 CHECK G SENSOR.
1) Connect connector to G sensor.
2) Connect connector to ABSCM&H/U.
3) Turn ignition switch to ON.
4) Measure voltage between G sensor con-
nector terminals.
Connector & terminal
(R70) No. 2 (+) — No. 3 (−):
19 CHECK G SENSOR.
Measure voltage between G sensor connector
terminals.
Connector & terminal
(R70) No. 2 (+) — No. 3 (−):
20 CHECK G SENSOR.
Measure voltage between G sensor connector
terminals.
Connector & terminal
(R70) No. 2 (+) — No. 3 (−):
Step
Is the voltage less than 1
V?
Is there poor contact in
connector between
ABSCM&H/U and G sen-
sor?
Is the same DTC as in the
current diagnosis still being
output?
Are other DTC being out-
put?
Is the voltage between 4.75
and 5.25 V?
Is the resistance between
4.3 and 4.9 kΩ?
Is the voltage between 2.1
and 2.5 V when G sensor
is horizontal?
Is the voltage between 3.7
and 4.1 V when G sensor
is inclined forwards to 90°?
Is the voltage between 0.5
and 0.9 V when G sensor
is inclined backwards to
90°?
ABS-148
Check Yes
Go to step 13.
Repair connector.
Replace
ABSCM&H/U.
<Ref. to ABS-6,
ABS Control Mod-
ule and Hydraulic
Control Unit
(ABSCM&H/U).>
Proceed with the
diagnosis corre-
sponding to the
DTC.
Go to step 17.
Go to step 18.
Go to step 19.
Go to step 20.
Go to step 21.
No
Repair harness
between G sensor
and ABSCM&H/U.
Go to step 14.
Go to step 15.
A temporary poor
contact.
Repair harness/
connector
between G sensor
and ABSCM&H/U.
Repair harness/
connector
between G sensor
and ABSCM&H/U.
Replace G sen-
sor. <Ref. to ABS-
22, G Sensor.>
Replace G sen-
sor. <Ref. to ABS-
22, G Sensor.>
Replace G sen-
sor. <Ref. to ABS-
22, G Sensor.>