Subaru Impreza 2002 Service Manual page 515

DIAGNOSTICS CHART WITH DIAGNOSIS CONNECTOR
ABS (DIAGNOSTICS)
Step
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. 29 (+) — Chassis
ground ( − − − − ):
RHD: (F49) No. 29 (+) — Chassis ground
( − − − − ):
8 CHECK GROUND SHORT OF HARNESS.
Measure the resistance between ABSCM&H/U
connector and chassis ground.
Connector & terminal
LHD: (B301) No. 28 — Chassis ground:
RHD: (F49) No. 28 — Chassis ground:
9 CHECK LATERAL G SENSOR.
1)Turn the ignition switch to OFF.
2)Remove the lateral G sensor from vehicle.
3)Connect the connector to lateral G sensor.
4)Connect the connector to ABSCM&H/U.
5)Turn the ignition switch to ON.
6)Measure the voltage between lateral G sen-
sor connector terminals.
Connector & terminal
(B257) No. 2 (+) — No. 3 ( − − − − ):
10 CHECK LATERAL G SENSOR.
Measure the voltage between lateral G sensor
connector terminals.
Connector & terminal
(B257) No. 2 (+) — No. 3 ( − − − − ):
11 CHECK LATERAL G SENSOR.
Measure the voltage between lateral G sensor
connector terminals.
Connector & terminal
(B257) No. 2 (+) — No. 3 ( − − − − ):
12 CHECK POOR CONTACT IN CONNECTORS. Is there poor contact in con-
13 CHECK ABSCM&H/U.
1)Connect all connectors.
2)Erase the memory.
3)Perform inspection mode.
4)Read out the DTC.
14 CHECK ANY OTHER DIAGNOSTIC TROU-
BLE CODES (DTCs) APPEARANCE.
Check
Is the voltage less than 1 V?
Is the resistance more than 1
MΩ?
Is the voltage between 2.3 and
2.7 V when lateral G sensor is
horizontal?
Is the voltage between 3.3 and
3.7 V when lateral G sensor is
inclined forwards to 90°?
Is the voltage between 1.3 and
1.7 V when lateral G sensor is
inclined backwards to 90°?
nector between ABSCM&H/U
and lateral G sensor?
Is the same DTC as in the cur-
rent diagnosis still being out-
put?
Are other DTCs being output? Proceed with the
ABS-18
Yes
Go to step 8. Repair the har-
ness between lat-
eral G sensor and
ABSCM&H/U.
Go to step 9. Repair the har-
ness between lat-
eral G sensor and
ABSCM&H/U.
Replace the
ABSCM&H/U.
<Ref. to ABS-4,
ABS Control Mod-
ule and Hydraulic
Control Unit
(ABSCM&H/U).>
Go to step 10. Replace the lateral
G sensor. <Ref. to
ABS-5, Lateral G
Sensor.>
Go to step 11. Replace the lateral
G sensor. <Ref. to
ABS-5, Lateral G
Sensor.>
Go to step 12. Replace the lateral
G sensor. <Ref. to
ABS-5, Lateral G
Sensor.>
Repair the con- Go to step 13.
nector.
Replace the Go to step 14.
ABSCM&H/U.
<Ref. to ABS-4,
ABS Control Mod-
ule and Hydraulic
Control Unit
(ABSCM&H/U).>
A temporary poor
diagnosis corre- contact.
sponding to DTC.
No