Subaru Impreza 2003 Service Manual page 2484

DIAGNOSTICS PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
ABS (DIAGNOSTICS)
Step
1 CHECK BATTERY SHORT OF HARNESS.
1)Turn the ignition switch to OFF.
2)Disconnect all connectors from TCM.
3)Disconnect the connector from ABSCM&
H/U.
4)Measure the voltage between ABSCM&H/U
connector and chassis ground.
Connector & terminal
LHD: (B301) No. 3 (+) — Chassis ground
( − − − − ):
RHD: (F49) No. 3 (+) — Chassis ground
( − − − − ):
2 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. 3 (+) — Chassis ground
( − − − − ):
RHD: (F49) No. 3 (+) — Chassis ground
( − − − − ):
3 CHECK OPEN CIRCUIT OF HARNESS.
1)Turn the ignition switch to OFF.
2)Connect all connectors to TCM.
3)Turn the ignition switch to ON.
4)Measure the voltage between ABSCM&H/U
connector and chassis ground.
Connector & terminal
LHD:
(B301) No. 3 (+) — Chassis ground ( − − − − ):
(B301) No. 31 (+) — Chassis ground ( − − − − ):
RHD:
(F49) No. 3 (+) — Chassis ground ( − − − − ):
(F49) No. 31 (+) — Chassis ground ( − − − − ):
4 CHECK POOR CONTACT IN CONNECTORS.
Turn the ignition switch to OFF.
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 voltage less than 1 V?
Is the voltage less than 1 V?
Is the voltage 10 — 15 V?
Is there poor contact in con-
nectors between TCM and
ABSCM&H/U?
Is the same DTC as in current
diagnosis still being output?
Are other DTCs being output? Proceed with the
ABS-144
Yes
Go to step 2. Repair the har-
ness between
TCM and
ABSCM&H/U.
Go to step 3. Repair the har-
ness between
TCM and
ABSCM&H/U.
Go to step 4. Repair the har-
ness/connector
between TCM and
ABSCM&H/U.
Repair the con- Go to step 5.
nector.
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