Subaru Impreza 2003 Service Manual page 2414

DIAGNOSTICS PROCEDURE WITHOUT DIAGNOSTIC TROUBLE CODE (DTC)
ABS (DIAGNOSTICS)
Step
1 CHECK GROUND CIRCUIT OF ABSCM&H/U.
1)Turn the ignition switch to OFF.
2)Disconnect the connector from ABSCM&
H/U.
3)Measure the resistance between
ABSCM&H/U and chassis ground.
Connector & terminal
LHD: (B301) No. 23 — Chassis ground:
RHD: (F49) No. 23 — Chassis ground:
2 CHECK POOR CONTACT IN CONNECTORS. Is there poor contact in con-
3 CHECK SOURCES OF SIGNAL NOISE.
4 CHECK SOURCES OF SIGNAL NOISE.
5 CHECK ABSCM&H/U.
1)Connect all connectors.
2)Erase the memory.
3)Perform the inspection mode.
4)Read out the DTC.
6 CHECK ANY OTHER DTC APPEARANCE.
Check
Is the resistance less than 0.5
Ω?
nectors between battery, igni-
tion switch and ABSCM&H/U?
Is the car telephone or the
wireless transmitter properly
installed?
Are noise sources (such as an
antenna) installed near the
sensor harness?
Is the same DTC as in current
diagnosis still being output?
Are other DTCs being output? Proceed with the
ABS-74
Yes
Go to step 2. Repair the
ABSCM&H/U
ground harness.
Repair the con- Go to step 3.
nector.
Go to step 4. Properly install the
car telephone or
wireless transmit-
ter.
Install the noise Go to step 5.
sources apart from
the sensor har-
ness.
Replace the Go to step 6.
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.
No