
4AT(H4SO)-105
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure without Diagnostic Trouble Code (DTC)
64 CHECK HARNESS CONNECTOR BETWEEN
TCM AND INHIBITOR SWITCH.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from TCM,
inhibitor switch and combination meter.
3) Measure the resistance of harness
between TCM and chassis ground.
Connector & terminal
(B55) No. 7 — Chassis ground:Is the resistance more than 1
MΩ?Go to step 65.Repair the ground
short circuit in “1”
range circuit.
65 CHECK POOR CONTACT.Is there poor contact in inhibi-
tor switch circuit?Repair the poor
contact.Go to step 66.
66 INSPECT INHIBITOR SWITCH.Is the inhibitor switch position
in normal position?Replace the TCM.
trol Module
(TCM).>Adjust the inhibi-
tor switch and
select cable.
ADJUSTMENT,
Inhibitor Switch.>

4AT(H4SO)-108
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure without Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK HOLD SWITCH OPERATION.When the HOLD switch is
turned to OFF, does LED light
up?Go to step 5.Go to step 2.
2 CHECK HOLD SWITCH OPERATION.When the HOLD switch is turned
to ON, does LED light up?Refer to “Symptom
Related Diagnos-
tic”.
Symptom Related
Diagnostic.>Go to step 3.
3 CHECK HOLD INDICATOR LIGHT.
1) Turn the ignition switch to OFF.
2) Disconnect the TCM connector.
3) Turn the ignition switch to ON.
4) Short the combination meter connector to
chassis ground.
CAUTION:
Be sure to short through fuse.
Connector & terminal
(i10) No. 19 — Chassis ground:Does the HOLD indicator light
illuminate?Go to step 4.Inspect the combi-
nation meter.
Meter Assembly.>
4 CHECK HOLD SWITCH GROUND LINE.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from HOLD
switch.
3) Measure the resistance of harness connec-
tor between HOLD switch and chassis ground.
Connector & terminal
LHD model
(R92) No. 4 — Chassis ground:
RHD model
(B133) No. 4 — Chassis ground:Is the resistance less than 1
Ω?Go to step 5.Repair the open
circuit in harness
between HOLD
switch and chas-
sis ground.
5 CHECK HOLD SWITCH.
1) Turn the HOLD switch to ON.
2) Measure the resistance between terminals
of HOLD switch.
Te r m i n a l s
No. 4 — No. 3:Is the resistance less than 1
Ω?Go to step 6.Replace the HOLD
switch.
6 CHECK HOLD SWITCH.
1) Turn the HOLD switch to OFF.
2) Measure the resistance between terminals
of HOLD switch.
Te r m i n a l s
No. 4 — No. 3:Is the resistance more than 1
MΩ?Go to step 7.Replace the HOLD
switch.
7 CHECK HARNESS CONNECTOR BETWEEN
TCM AND HOLD SWITCH.
1) Disconnect the connector TCM and combi-
nation meter.
2) Measure the resistance of harness connec-
tor between TCM and HOLD switch.
Connector & terminal
LHD model
(B55) No. 16 — (R92) No. 2:
RHD model
(B55) No. 16 — (B133) No. 2:Is the resistance less than 1
Ω?Go to step 8.Repair the open
circuit in harness
between TCM and
HOLD switch con-
nector and poor
contact in cou-
pling connector.
8 CHECK HARNESS CONNECTOR BETWEEN
TCM AND COMBINATION METER.
Measure the resistance of harness connector
TCM and combination meter.
Connector & terminal
(B55) No. 16 — (i10) No. 19:Is the resistance less than 1
Ω?Go to step 9.Repair the open
circuit in harness
between TCM and
combination
meter, and poor
contact in cou-
pling connector.

4AT(H4DOTC)-2
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Basic Diagnostic Procedure
1. Basic Diagnostic Procedure
A: PROCEDURE
Step Check Yes No
1 CHECK PRE-INSPECTION.
1) Ask the customer when and how trouble
occurred using interview checklist.
2) Before performing the diagnosis, inspect
following items which might influence the AT
problems.
General inspection
Disconnection of harness connector
Visually check the damage of harness
Oil leak
Stall speed test
Line pressure test
Transfer clutch pressure test
Time lag test
Road test
Inhibitor switch
AT problem normal?Go to step 2.Repair or replace
each item.
2 CHECK POWER INDICATOR LIGHT.
Turn the ignition switch to ON.Does the POWER indicator
light illuminate?Go to step 4.Go to step 3.
3 CHECK POWER INDICATOR LIGHT.
1) Turn the ignition switch to OFF.
2) Repair the POWER indicator light circuit or
power supply and ground line circuit.
3) Turn the ignition switch to ON.Is the POWER indicator light
flashing?Go to step 4.Go to step 5.
4 READ OF DTC.
Calling up the DTC.
N
OTE:
If the communication function of Subaru Select
Monitor cannot be executed normally, check the
communication circuit.
POSSIBLE, Diagnostic Procedure for Subaru
Select Monitor Communication.>Is the DTC displayed? Go to step 6.
NOTE:
Record all DTC.Go to step 5.
5 PERFORM THE GENERAL DIAGNOSTICS.
1) Inspect using “Diagnostics Procedure with-
out DTC”.
Code (DTC).>
2) Inspect using “Symptom Related Diagnos-
tic”.
3) Perform the clear memory mode.
4) Perform the inspection mode.
5) Calling up the DTC.Is the DTC displayed? Go to step 6.Complete the
diagnosis.

4AT(H4DOTC)-24
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Power Indicator Light Display
4 CHECK HARNESS CONNECTOR BETWEEN
COMBINATION METER AND IGNITION
SWITCH.
1) Turn the ignition switch to ON (engine OFF).
2) Measure the voltage between combination
meter connector and chassis ground.
Connector & terminal
(i10) No. 9 (+) — Chassis ground (
−):Is the voltage more than 9 V? Go to step 5.Repair the open
circuit in harness
between combina-
tion meter and bat-
tery.
5 CHECK COMBINATION METER.
Measure the voltage between combination
meter connector and chassis ground.
Connector & terminal
(i11) No. 2 (+) — Chassis ground (
−):Is the voltage less than 9 V? Repair the combi-
nation meter.
Meter Assembly.>Go to step 6.
6 CHECK OPEN CIRCUIT OF HARNESS.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from combination
meter connector.
3) Measure the resistance of harness
between combination meter.
Connector & terminal
(B56) No. 25 — (i11) No. 2:Is the resistance less than 1
Ω?Go to step 7.Repair the open
circuit in harness
between TCM and
combination
meter, and poor
contact in cou-
pling connector.
7 CHECK INPUT SIGNAL FOR TCM.
1) Connect the connector to TCM and combi-
nation meter.
2) Turn the ignition switch to ON (engine OFF).
3) Measure the voltage between TCM con-
nector and chassis ground.
Connector & terminal
(B56) No. 25 (+) — Chassis ground (
−):Is the voltage less than 1 V? Go to step 8.Replace the TCM.
trol Module
(TCM).>
8 INSPECT POWER INDICATOR LIGHT.Does the POWER indicator
light illuminate?Diagnose accord-
ing to basic diag-
nostic procedure.Inspect power sup-
ply and ground cir-
cuit. Step Check Yes No

4AT(H4DOTC)-26
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Power Indicator Light Display
2 CHECK POWER SUPPLY OF TCM.
1) Disconnect the connector from TCM.
2) Turn the ignition switch to ON.
3) Measure the voltage between TCM con-
nector and chassis ground.
Connector & terminal
(B56) No. 27 (+) — Chassis ground (
−):
(B56) No. 28 (+) — Chassis ground (
−):
(B56) No. 29 (+) — Chassis ground (
−):Is the voltage 10 — 13 V? Go to step 4.Go to step 3.
3 CHECK FUSE (No. 4).
1) Turn the ignition switch to OFF.
2) Remove the fuse (No. 4).Is the fuse (No. 4) blown out? Replace the fuse
(No. 4). If replaced
fuse (No. 4) has
blown out easily,
repair short circuit
in harness between
fuse (No. 4) and
TCM.Repair the open
circuit in harness
between fuse (No.
4) and TCM, or
fuse (No. 4) and
battery, and poor
contact in cou-
pling connector.
4 CHECK IGNITION POWER SUPPLY CIR-
CUIT.
1) Turn the ignition switch to ON (engine OFF).
2) Measure the ignition power supply voltage
between TCM connector and chassis ground.
Connector & terminal
(B56) No. 21 (+) — Chassis ground (–):
(B56) No. 31 (+) — Chassis ground (–):Is the voltage 10 — 13 V? Go to step 6.Go to step 5.
5 CHECK FUSE (No. 11).
Remove the fuse (No. 11).Is the fuse (No. 11) blown out? Replace the fuse
(No. 11). If
replaced fuse (No.
11) has blown out
easily, repair short
circuit in harness
between fuse (No.
11) and TCM.Repair the open
circuit in harness
between fuse (No.
11) and TCM, or
fuse (No. 11) and
battery, and poor
contact in cou-
pling connector.
6 CHECK HARNESS CONNECTOR BETWEEN
TCM AND TRANSMISSION.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from TCM and
transmission.
3) Measure the resistance of harness
between TCM and transmission connector.
Connector & terminal
(B55) No. 8 — (B11) No. 19:
(B55) No. 17 — (B11) No. 19:
(B56) No. 2 — (B11) No. 20:
(B56) No. 3 — (B11) No. 20:Is the resistance less than 1
Ω?Go to step 7.Repair the open
circuit in harness
between TCM,
transmission har-
ness connector,
and poor contact
in coupling con-
nector.
7 CHECK HARNESS CONNECTOR BETWEEN
TRANSMISSION AND TRANSMISSION
GROUND.
Measure the resistance of harness between
transmission and transmission ground.
Connector & terminal
(T4) No. 19 — Transmission ground:
(T4) No. 20 — Transmission ground:Is the resistance less than 1
Ω?Go to step 8.Repair the open
circuit in harness
between transmis-
sion and transmis-
sion ground.
8 CHECK POOR CONTACT IN CONNECTORS.Is there poor contact in TCM
power supply, ground line and
data link connector?Repair the con-
nector.Replace the TCM.
trol Module
(TCM).> Step Check Yes No

4AT(H4DOTC)-35
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
8 CHECK INDICATOR LIGHT.Does the combination meter
“N” range indicator illuminate?Go to step 9.Go to step 38.
9 CHECK “N” RANGE SWITCH.When the “D” range is selected,
does “N” range LED light up?Go to step 40.Go to step 10.
10 CHECK “D” RANGE SWITCH.When the “D” range is
selected, does LED light up?Go to step 11.Go to step 41.
11 CHECK INDICATOR LIGHT.Does the combination meter
“D” range indicator illuminate?Go to step 12.Go to step 44.
12 CHECK “D” RANGE SWITCH.When the “3” range is selected,
does “D” range LED light up?Go to step 46.Go to step 13.
13 CHECK “3” RANGE SWITCH.When the “3” range is selected,
does LED light up?Go to step 14.Go to step 47.
14 CHECK INDICATOR LIGHT.Does the combination meter
“3” range indicator illuminate?Go to step 15.Go to step 50.
15 CHECK “3” RANGE SWITCH.When the “2” range is selected,
does “3” range LED light up?Go to step 52.Go to step 16.
16 CHECK “2” RANGE SWITCH.When the “2” range is selected,
does LED light up?Go to step 17.Go to step 53.
17 CHECK INDICATOR LIGHT.Does the combination meter
“2” range indicator illuminate?Go to step 18.Go to step 56.
18 CHECK “2” RANGE SWITCH.When the “1” range is selected,
does “2” range LED light up?Go to step 58.Go to step 19.
19 CHECK “1” RANGE SWITCH.When the “1” range is selected,
does LED light up?Go to step 20.Go to step 59.
20 CHECK INDICATOR LIGHT.Does the combination meter
“1” range indicator illuminate?Go to step 21.Go to step 62.
21 CHECK “1” RANGE SWITCH.When the “2” range is selected,
does “1” range LED light up?Go to step 64.Replace the TCM.
trol Module
(TCM).>
22 CHECK HARNESS CONNECTOR BETWEEN
INHIBITOR SWITCH AND CHASSIS
GROUND.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from inhibitor
switch.
3) Measure the resistance of harness
between inhibitor switch and chassis ground.
Connector & terminal
(T7) No. 5 — Chassis ground:Is the resistance less than 1
Ω?Go to step 23.Repair the open
circuit in harness
between inhibitor
switch and chassis
ground, and poor
contact in coupling
connector.
23 CHECK HARNESS CONNECTOR BETWEEN
TCM AND INHIBITOR SWITCH.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from TCM and
inhibitor switch.
3) Measure the resistance of harness
between TCM and inhibitor switch connector.
Connector & terminal
(B55) No. 5 — (T7) No. 9:Is the resistance less than 1
Ω?Go to step 24.Repair the open cir-
cuit in harness
between TCM and
inhibitor switch con-
nector, and poor
contact in coupling
connector. Step Check Yes No

4AT(H4DOTC)-36
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
24 CHECK INPUT SIGNAL FOR TCM.
1) Turn the ignition switch to OFF.
2) Connect the connector to TCM and inhibitor
switch.
3) Turn the ignition switch to ON.
4) Shift the select lever to “P” range.
5) Measure the voltage between TCM and
chassis ground.
Connector & terminal
(B55) No. 5 (+) — Chassis ground (–):Is the voltage less than 1 V? Go to step 25.Go to step 65.
25 CHECK INPUT SIGNAL FOR TCM.
1) Shift the select lever except for “P” range.
2) Measure the voltage between TCM and
chassis ground.
Connector & terminal
(B55) No. 5 (+) — Chassis ground (–):Is the voltage more than 8 V? Go to step 65.Replace the TCM.
trol Module
(TCM).>
26 CHECK “P” RANGE INDICATOR LIGHT
BULB.
1) Turn the ignition switch to OFF.
2) Remove the combination meter.
3) Remove the “P” range indicator light bulb
from combination meter.Is the “P” range indicator light
bulb OK?Go to step 27.Replace the “P”
range indicator light
bulb.
Meter Assembly.>
27 CHECK HARNESS CONNECTOR BETWEEN
TCM AND COMBINATION METER.
1) Disconnect the connectors from TCM and
combination meter.
2) Measure the resistance of harness
between TCM and combination meter.
Connector & terminal
(B55) No. 5 — (i12) No. 14:Is the resistance more than 1
Ω?Go to step 65.Repair the open cir-
cuit in harness
between TCM con-
nector and combi-
nation meter, and
poor contact in cou-
pling connector.
28 CHECK HARNESS CONNECTOR BETWEEN
TCM AND INHIBITOR SWITCH.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from TCM,
inhibitor switch and combination meter.
3) Measure the resistance of harness
between TCM connector and chassis ground.
Connector & terminal
(B55) No. 5 — Chassis ground:Is the resistance less than 1
MΩ?Go to step 29.Repair the ground
short circuit in “P”
range circuit.
29 CHECK HARNESS CONNECTOR BETWEEN
TCM AND INHIBITOR SWITCH.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from TCM and
inhibitor switch.
3) Measure the resistance of harness
between TCM and inhibitor switch connector.
Connector & terminal
(B55) No. 14 — (T7) No. 8:Is the resistance less than 1
Ω?Go to step 30.Repair the open cir-
cuit in harness
between TCM and
inhibitor switch con-
nector, and poor
contact in coupling
connector.
30 CHECK INPUT SIGNAL FOR TCM.
1) Turn the ignition switch to OFF.
2) Connect the connector to TCM and inhibitor
switch.
3) Turn the ignition switch to ON.
4) Shift the select lever to “R” range.
5) Measure the voltage between TCM and
chassis ground.
Connector & terminal
(B55) No. 14 (+) — Chassis ground (–):Is the voltage less than 1 V? Go to step 31.Go to step 65. Step Check Yes No

4AT(H4DOTC)-37
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
31 CHECK INPUT SIGNAL FOR TCM.
1) Move the select lever except for “R” range.
2) Measure the voltage between TCM and
chassis ground.
Connector & terminal
(B55) No. 14 (+) — Chassis ground (–):Is the voltage more than 8 V? Go to step 65.Replace the TCM.
trol Module
(TCM).>
32 CHECK “R” RANGE INDICATOR LIGHT
BULB.
1) Turn the ignition switch to OFF.
2) Remove the combination meter.
3) Remove the “R” range indicator light bulb
from combination meter.Is “R” range indicator light bulb
OK?Go to step 33.Replace the “R”
range indicator light
bulb.
Meter Assembly.>
33 CHECK HARNESS CONNECTOR BETWEEN
TCM AND COMBINATION METER.
1) Disconnect the connectors from TCM and
combination meter.
2) Measure the resistance of harness
between TCM and combination meter.
Connector & terminal
(B55) No. 14 — (i12) No. 13:Is the resistance less than 1
Ω?Go to step 65.Repair the open
circuit in harness
between TCM con-
nector and combi-
nation meter, and
poor contact in
TCM connector.
34 CHECK HARNESS CONNECTOR BETWEEN
TCM AND INHIBITOR SWITCH.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from TCM,
inhibitor switch and combination meter.
3) Measure the resistance of harness
between TCM and chassis ground.
Connector & terminal
(B55) No. 14 — Chassis ground:Is the resistance more than 1
MΩ?Go to step 35.Repair the ground
short circuit in “R”
range circuit.
35 CHECK HARNESS CONNECTOR BETWEEN
TCM AND INHIBITOR SWITCH.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from TCM and
inhibitor switch.
3) Measure the resistance of harness
between TCM and inhibitor switch connector.
Connector & terminal
(B55) No. 22 — (T7) No. 10:Is the resistance less than 1
Ω?Go to step 36.Repair the open cir-
cuit in harness
between TCM and
inhibitor switch con-
nector, and poor
contact in coupling
connector.
36 CHECK INPUT SIGNAL FOR TCM.
1) Turn the ignition switch to OFF.
2) Connect the connector to TCM and inhibitor
switch.
3) Turn the ignition switch to ON.
4) Shift the select lever to “N” range.
5) Measure the voltage between TCM and
chassis ground.
Connector & terminal
(B55) No. 22 (+) — Chassis ground (–):Is the voltage less than 1 V? Go to step 37.Go to step 65.
37 CHECK INPUT SIGNAL FOR TCM.
1) Shift the select lever to except for “N”
range.
2) Measure the voltage between TCM and
chassis ground.
Connector & terminal
(B55) No. 22 (+) — Chassis ground (–):Is the voltage more than 8 V? Go to step 65.Replace the TCM.
trol Module
(TCM).> Step Check Yes No