Subaru Impreza 2003 Service Manual page 2526

DIAGNOSTICS PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
ABS (DIAGNOSTICS)
Step
2 CHECK POOR CONTACT IN CONNECTORS.
Turn the ignition switch to OFF.
3 CHECK ABSCM&H/U.
1)Connect all connectors.
2)Erase the memory.
3)Perform the inspection mode.
4)Read out the DTC.
4 CHECK ANY OTHER DTC APPEARANCE.
5 CHECK OPEN CIRCUIT IN LATERAL G SEN-
SOR OUTPUT 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. 29 — No. 28:
RHD: (F49) No. 29 — No. 28:
6 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:
7 CHECK LATERAL G SENSOR.
1)Remove the console box.
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 ( − − − − ):
8 CHECK LATERAL G SENSOR.
Measure the voltage between lateral G sensor
connector terminals.
Connector & terminal
(B257) No. 2 (+) — No. 3 ( − − − − ):
9 CHECK LATERAL G SENSOR.
Measure the voltage between lateral G sensor
connector terminals.
Connector & terminal
(B257) No. 2 (+) — No. 3 ( − − − − ):
Check
Is there poor contact in con-
nector between ABSCM&H/U
and lateral G sensor?
Is the same DTC as in current
diagnosis still being output?
Are other DTCs being output? Proceed with the
Is the resistance 5.0 — 5.6
kΩ?
Is the resistance more than 1
MΩ?
Is the voltage 2.1 — 2.5 V
when lateral G sensor is in hor-
izontal position?
Is the voltage 3.3 — 3.7 V
when lateral G sensor is
inclined right to 90°?
Is the voltage 0.5 — 0.9 V
when lateral G sensor is
inclined left to 90°?
ABS-186
Yes
Repair the con- Go to step 3.
nector.
Replace the Go to step 4.
ABSCM&H/U.
<Ref. to ABS-7,
ABS Control Mod-
ule and Hydraulic
Control Unit
(ABSCM&H/U).>
A temporary poor
diagnosis corre- contact.
sponding to DTC.
Go to step 6. Repair the har-
ness/connector
between lateral G
sensor and
ABSCM&H/U.
Go to step 7. Repair the har-
ness between lat-
eral G sensor and
ABSCM&H/U.
Replace the
ABSCM&H/U.
<Ref. to ABS-7,
ABS Control Mod-
ule and Hydraulic
Control Unit
(ABSCM&H/U).>
Go to step 8. Replace the lateral
G sensor. <Ref. to
ABS-23, Lateral G
Sensor.>
Go to step 9. Replace the lateral
G sensor. <Ref. to
ABS-23, Lateral G
Sensor.>
Go to step 10. Replace the lateral
G sensor. <Ref. to
ABS-23, Lateral G
Sensor.>
No