Subaru Impreza 2003 Service Manual page 2482

DIAGNOSTICS PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
ABS (DIAGNOSTICS)
Step
2 CHECK GROUND SHORT OF HARNESS.
1)Turn the ignition switch to OFF.
2)Disconnect the two connectors from TCM.
3)Disconnect the connector from ABSCM&
H/U.
4)Measure the resistance between
ABSCM&H/U connector and chassis ground.
Connector & terminal
LHD: (B301) No. 3 — Chassis ground:
RHD: (F49) No. 3 — Chassis ground:
3 CHECK TCM.
1)Connect all connectors to TCM.
2)Turn the ignition switch to ON.
3)Measure the voltage between TCM connec-
tor terminal and chassis ground.
Connector & terminal
(B55) No. 21 (+) — Chassis ground ( − − − − ):
4 CHECK AT.
5 CHECK OPEN CIRCUIT OF HARNESS.
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 ( − − − − ):
6 CHECK POOR CONTACT IN CONNECTORS. Is there poor contact in con-
7 CHECK ABSCM&H/U.
1)Connect all connectors.
2)Erase the memory.
3)Perform the inspection mode.
4)Read out the DTC.
8 CHECK ANY OTHER DTC APPEARANCE.
Check
Is the resistance more than 1
MΩ?
Is the voltage 10 — 15 V?
Is the AT functioning normally? Replace the TCM. Repair the AT.
Is the voltage 10 — 15 V?
nectors between TCM and
ABSCM&H/U?
Is the same DTC as in the cur-
rent diagnosis still being out-
put?
Are other DTCs being output? Proceed with the
ABS-142
Yes
Go to step 3. Repair the har-
ness between
TCM and
ABSCM&H/U.
Go to step 5. Go to step 4.
Go to step 6. Repair the har-
ness/connector
between TCM and
ABSCM&H/U.
Repair the con- Go to step 7.
nector.
Replace the Go to step 8.
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