Subaru IMPREZA 2002 Service Manual page 261

ii
DIAGNOSTICS CHART WITH DIAGNOSIS CONNECTOR
ABS (DIAGNOSTICS)
Step
1
CHECK SPECIFICATIONS OF THE AB-
SCM&H/U.
Check specifications of the mark to the
ABSCM&H/U.
CC: AT
CD:
MT
2
CHECK GROUND SHORT OF HARNESS.
1)Turn the ignition switch to OFF.
2)Disconnect 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
(F49) No. 3
-
Chassis ground:
3
CHECK BATTERY SHORT OF HARNESS.
Measure the voltage between ABSCM&H/U
connector and chassis ground.
Connector & terminal
(F49) No. 3 (+)
-
Chassis ground ( - ) :
4
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
(F49) No, 3 (+)
-
Chassis ground (-):
5 CHECK TCM.
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 TCM connec-
tor terminal and chassis ground.
Connector & terminal
NON-TURBO MODEL
(B54) No. 19 (+)
-
Chassis ground (-):
TURBO MODEL
(B55) No. 21 (+)
-
Chassis ground ( - ) :
6 CHECK AT.
7
CHECK OPEN CIRCUIT OF HARNESS.
Measure the voltage between ABSCM&H/U
connector and chassis ground.
Connector & terminal
(F49) No. 3 (+)
-
Chassis ground (-):
(F49) No. 31 (+)
-
Chassis ground (-):
CHECK POOR CONTACT IN CONNECTORS
8
9 CHECK ABSCM&H/U.
1)Turn the ignition switch to OFF.
2)Connect all connectors.
3)Erase the memory.
4)Perform the inspection mode.
5)Read out the diagnostic trouble code.
Check
Is an ABSCM&H/U for AT
model installed on a MT
nodel?
Is the resistance more than 1
MQ?
Is the voltage less than 1 V?
Is the voltage less than 1 V?
Is the voltage between
10
and
15 V?
Is the AT functioning normally?
Is the voltage between 10 and
15 V?
Is there poor contact in con-
nectors between TCM and
ABSCM&H/U?
Is the same diagnostic trouble
code as in the current diagno-
sis still being output?
Yes
3eplace the
4BSCM&H/U.
:Ref. to ABS-7,
9BS Control Mod-
de and Hydraulic
2ontrol Unit
:ABSCM&H/U). >
30 to step 3 .
30 to step 4.
30 to step 5.
Go to step 7.
Replace the TCM.
Go to step 8.
Repair the con-
nector.
Replace the
ABSCM&H/U.
<Ref. to ABS-7,
ABS Control Mod-
ule and Hydraulic
Control Unit
(ABSCM&H/U).r
No
Go to step 2.
Repair harness
between TCM and
ABSCM&H/U.
Repair harness
between TCM and
ABSCM&H/U.
Repair harness
between TCM and
ABSCM&H/U.
Go to step 6.
Repair the AT.
Repair harness/
connector
between TCM and
ABSCM&H/U.
Go to step 9.
Go to step 10.
ABS-75