
4AT(H4DOTC)-38
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
38 CHECK “N” RANGE INDICATOR LIGHT
BULB.
1) Turn the ignition switch to OFF.
2) Remove the combination meter.
3) Remove the “N” range indicator light bulb
from combination meter.Is the “N” range indicator light
bulb OK?Go to step 39.Replace the “N”
range indicator light
bulb.
Meter Assembly.>
39 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. 22 — (i12) No. 12: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.
40 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. 22 — Chassis ground:Is the resistance more than 1
MΩ?Go to step 41.Repair the ground
short circuit in “N”
range circuit.
41 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. 4 — (T7) No. 3:Is the resistance less than 1
Ω?Go to step 42.Repair the open cir-
cuit in harness
between TCM and
inhibitor switch con-
nector, and poor
contact in coupling
connector.
42 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 “D” range.
5) Measure the voltage between TCM and
chassis ground.
Connector & terminal
(B55) No. 4 (+) — Chassis ground (–):Is the voltage less than 1 V? Go to step 43.Go to step 65.
43 CHECK INPUT SIGNAL FOR TCM.
1) Shift the select lever except for “D” range.
2) Measure the voltage between TCM and
chassis ground.
Connector & terminal
(B55) No. 4 (+) — Chassis ground (–):Is the voltage more than 8 V? Go to step 65.Replace the TCM.
trol Module
(TCM).>
44 CHECK “D” RANGE INDICATOR LIGHT
BULB.
1) Turn the ignition switch to OFF.
2) Remove the combination meter.
3) Remove the “D” range indicator light bulb
from combination meter.Is the “D” range indicator light
bulb OK?Go to step 45.Replace the “D”
range indicator light
bulb.
Meter Assembly.> Step Check Yes No

4AT(H4DOTC)-39
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
45 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. 4 — (i12) No. 11: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.
46 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. 4 — Chassis ground:Is the resistance more than 1
MΩ?Go to step 47.Repair the ground
short circuit in “D”
range circuit.
47 CHECK HARNESS CONNECTOR BETWEEN
TCM AND INHIBITOR SWITCH.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from TCM and
inhibitor switch.
3) Measure the resistance of harness
between TCM and inhibitor switch connector.
Connector & terminal
(B54) No. 16 — (T7) No. 11:Is the resistance less than 1
Ω?Go to step 48.Repair the open cir-
cuit in harness
between TCM and
inhibitor switch con-
nector, and poor
contact in coupling
connector.
48 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 “3” range.
5) Measure the voltage between TCM and
chassis ground.
Connector & terminal
(B54) No. 16 (+) — Chassis ground (–):Is the voltage less than 1 V? Go to step 49.Go to step 65.
49 CHECK INPUT SIGNAL FOR TCM.
1) Shift the select lever except for “3” range.
2) Measure the voltage between TCM and
chassis ground.
Connector & terminal
(B54) No. 16 (+) — Chassis ground (–):Is the voltage more than 8 V? Go to step 65.Replace the TCM.
trol Module
(TCM).>
50 CHECK “3” RANGE INDICATOR LIGHT
BULB.
1) Turn the ignition switch to OFF.
2) Remove the combination meter.
3) Remove the “3” range indicator light bulb
from combination meter.Is the “3” range indicator light
bulb OK?Go to step 51.Replace the “3”
range indicator light
bulb.
Meter Assembly.>
51 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
(B54) No. 16 — (i12) No. 10:Is the resistance more 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. Step Check Yes No

4AT(H4DOTC)-40
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
52 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
(B54) No. 16 — Chassis ground:Is the resistance more than 1
MΩ?Go to step 53.Repair the ground
short circuit in “3”
range circuit.
53 CHECK HARNESS CONNECTOR BETWEEN
TCM AND INHIBITOR SWITCH.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from TCM and
inhibitor switch.
3) Measure the resistance of harness
between TCM and inhibitor switch connector.
Connector & terminal
(B54) No. 4 — (T7) No. 4:Is the resistance less than 1
Ω?Go to step 54.Repair the open cir-
cuit in harness
between TCM and
inhibitor switch con-
nector, and poor
contact in coupling
connector.
54 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 “2” range.
5) Measure the voltage between TCM and
chassis ground.
Connector & terminal
(B54) No. 4 (+) — Chassis ground (–):Is the voltage less than 1 V? Go to step 55.Go to step 65.
55 CHECK INPUT SIGNAL FOR TCM.
1) Shift the select lever except for “2” range.
2) Measure the voltage between TCM and
chassis ground.
Connector & terminal
(B54) No. 4 (+) — Chassis ground (–):Is the voltage more than 8 V? Go to step 65.Replace the TCM.
trol Module
(TCM).>
56 CHECK “2” RANGE INDICATOR LIGHT
BULB.
1) Turn the ignition switch to OFF.
2) Remove the combination meter.
3) Remove the “2” range indicator light bulb
from combination meter.Is the “2” range indicator light
bulb OK?Go to step 57.Replace the “2”
range indicator light
bulb.
Meter Assembly.>
57 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
(B54) No. 4 — (i12) No. 4:Is the resistance less than 1
Ω?Go to step 65.Repair the open
circuit in harness
between TCM and
combination
meter, and poor
contact in TCM
connector.
58 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
(B54) No. 4 — Chassis ground:Is the resistance more than 1
MΩ?Go to step 59.Repair the ground
short circuit in “2”
range circuit. Step Check Yes No

4AT(H4DOTC)-41
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
59 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
(B54) No. 10 — (T7) No. 6:Is the resistance less than 1
Ω?Go to step 60.Repair the open cir-
cuit in harness
between TCM and
inhibitor switch con-
nector, and poor
contact in coupling
connector.
60 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 “1” range.
5) Measure the voltage between TCM and
chassis ground.
Connector & terminal
(B54) No. 10 (+) — Chassis ground (–):Is the voltage less than 1 V? Go to step 61.Go to step 65.
61 CHECK INPUT SIGNAL FOR TCM.
1) Shift the select lever except for “1” range.
2) Measure the voltage between TCM and
chassis ground.
Connector & terminal
(B54) No. 10 (+) — Chassis ground (–):Is the voltage more than 8 V? Go to step 65.Replace the TCM.
trol Module
(TCM).>
62 CHECK “1” RANGE INDICATOR LIGHT
BULB.
1) Turn the ignition switch to OFF.
2) Remove the combination meter.
3) Remove the “1” range indicator light bulb
from combination meter.Is the “1” range indicator light
bulb OK?Go to step 63.Replace the “1”
range indicator light
bulb.
Meter Assembly.>
63 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
(B54) No. 10 — (i12) No. 5:Is the resistance less than 1Ω? Go to step 65.Repair the open
circuit in harness
between TCM and
combination meter,
poor contact in
TCM connector.
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 connector and chassis ground.
Connector & terminal
(B54) No. 10 — 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 CHECK INHIBITOR SWITCH.Is the inhibitor switch in proper
position?Replace the TCM.
trol Module
(TCM).>Adjust the inhibi-
tor switch and
select cable.
tor Switch.> and

4AT(H4DOTC)-50
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
2 CHECK HARNESS CONNECTOR BETWEEN
TCM AND TRANSMISSION.
1) Disconnect the connector from TCM.
2) Measure the resistance of harness
between TCM and transmission connector.
Connector & terminal
(B55) No. 7 — (B11) No. 5:Is the resistance less than 1
Ω?Go to step 3.Repair the open
circuit in harness
between TCM and
transmission con-
nector.
3 CHECK HARNESS CONNECTOR BETWEEN
TCM AND TRANSMISSION.
Measure the resistance of harness between
TCM and transmission connector.
Connector & terminal
(B55) No. 16 — (B11) No. 10:Is the resistance less than 1
Ω?Go to step 4.Repair the open
circuit in harness
between TCM and
transmission con-
nector, and poor
contact in cou-
pling connector.
4 CHECK HARNESS CONNECTOR BETWEEN
TCM AND TRANSMISSION.
Measure the resistance of harness between
TCM connector and chassis ground.
Connector & terminal
(B55) No. 16 — Chassis ground:Is the resistance more than 1
MΩ?Go to step 5.Repair the short
circuit in harness
between TCM and
transmission con-
nector.
5 CHECK HARNESS CONNECTOR BETWEEN
TCM AND TRANSMISSION.
Measure the resistance of harness between
TCM connector and chassis ground.
Connector & terminal
(B55) No. 7 — Chassis ground:Is the resistance more than 1
MΩ?Go to step 6.Repair the short
circuit in harness
between TCM and
transmission con-
nector, and poor
contact in cou-
pling connector.
6 PREPARE OSCILLOSCOPE.Do you have an oscilloscope? Go to step 10.Go to step 7.
7 PREPARE SUBARU SELECT MONITOR.Do you have a Subaru Select
Monitor?Go to step 9.Go to step 8.
8 CHECK INPUT SIGNAL FOR TCM.
1) Connect the connectors to TCM and trans-
mission.
2) Start the engine and shift select lever to “P”
or “N” range.
3) Measure the voltage between TCM con-
nector terminals.
Connector & terminal
(B55) No. 7 (+) — No. 16 (
−):Is the voltage more than AC 1
V?Even if the POWER
indicator light was
blinking, the circuit
has returned to a
normal condition at
this time. A tempo-
rary poor contact of
the connector or
harness may be the
cause. Repair the
harness or connec-
tor in TCM and
transmission.Go to step 11.
9 CHECK INPUT SIGNAL FOR TCM USING
SUBARU SELECT MONITOR.
1) Connect the connectors to TCM and trans-
mission.
2) Connect the Subaru Select Monitor to data
link connector.
3) Turn the ignition switch to ON and turn Sub-
aru Select Monitor switch to ON.
4) Start the engine.
5) Shift the select lever to “P” or “N” range.
6) Read the data of turbine speed using Sub-
aru Select Monitor.
Compare the tachometer with Subaru Select
Monitor indications.Is the revolution value same as
the tachometer reading shown
on the combination meter?Even if the POWER
indicator light was
blinking, the circuit
has returned to a
normal condition at
this time. A tempo-
rary poor contact of
the connector or
harness may be the
cause. Repair the
harness or connec-
tor in TCM and
transmission.Go to step 11. Step Check Yes No

4AT(H4DOTC)-54
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
F: DTC P0720 OUTPUT SPEED SENSOR CIRCUIT
DTC DETECTING CONDITION:
The vehicle speed signal is abnormal.
The circuit in combination meter is faulty.
The harness connector between TCM and vehicle speed sensor is in short or open.
TROUBLE SYMPTOM:
Erroneous idling.
Engine stalls.
Poor driving performance.
WIRING DIAGRAM:
AT-01845
18 14
B11
B299
T4
B6
B15C1
B11
12 34
5678
9
13 14 15
20 19 1716 10 11 1218
i10
B37
i2
B38
i3
TCM
B55 B:
B56 C:
18
12
1234567813 14 15 16 17 18 1911 101225 26 27 28 29 30 31
921203223 2224
i3
B56
12 78 956 34
10 11 12 19 20 21
29 30 31 13 14 15 16 17
27 2818
22 23 24 25 26
C:
FRONT
VEHICLE SPEED
SENSOR CONBINATION
METER
SPEEDOMETER
: RHD MODEL SHIELD
JOINT
CONNECTOR
LHD
RHD
RHD
: LHD MODEL
LHD RHD
7
834
LHD
i10
123456789101112131415161718192021222324252627282930
B:B55
12 7
8956 34
10 11 12
19 20 2113 14 15 16
17 18 22 23 24
B37
34 12 89
10 11
12 13 14 15 16 17 18 19 20 21 22 23 24567
B299
12345678

4AT(H4DOTC)-56
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
9 CHECK FRONT VEHICLE SPEED SENSOR
USING OSCILLOSCOPE.
1) Connect all connectors.
2) Lift-up the vehicle and place rigid racks.
N
OTE:
Raise all wheels off ground.
3) Set the oscilloscope to TCM connector ter-
minals.
Connector & terminal
Positive probe; (B55) No. 6:
Earth lead; (B55) No. 15:
4) Start the engine, and drive the wheels
slowly.
N
OTE:
The speed difference between front and rear
wheels may light the ABS warning light, but this
indicates no malfunctions. When AT control di-
agnosis is finished, perform the ABS memory
clearance procedure of on-board diagnostic sys-
tem.
5) Measure the signal voltage indicated on
oscilloscope.Is the voltage more than AC 4
V?Even if the POWER
indicator light was
blinking, the circuit
has returned to a
normal condition at
this time. A tempo-
rary poor contact or
harness may be the
cause. Repair the
harness or connec-
tor in front vehicle
speed sensor cir-
cuit.Go to step 11.
10 CHECK INPUT SIGNAL FOR TCM USING
SUBARU SELECT MONITOR.
1) Connect all connectors.
2) Connect the Subaru Select Monitor to data
link connector.
3) Lift-up the vehicle and place rigid racks.
N
OTE:
Raise all wheels off floor.
4) Turn the ignition switch to ON and turn Sub-
aru Select Monitor switch to ON.
5) Start the engine.
6) Read the data of vehicle speed using Sub-
aru Select Monitor.
Compare the speedometer with Subaru
Select Monitor indications.
Vehicle speed is indicated in “km/h” or
“MPH”.
7) Slowly increase the vehicle speed to 60 km/
h (37 MPH).
N
OTE:
The speed difference between front and rear
wheels may light the ABS warning light, but this
indicates no malfunction. When AT control diag-
nosis is finished, perform the ABS memory clear-
ance procedure of on-board diagnostics system.
tion increase as Subaru Select
Monitor data increases?Even if the POWER
indicator light was
blinking, the circuit
has returned to a
normal condition at
this time. A tempo-
rary poor connec-
tor or harness may
be the cause.
Repair the harness
or connector in
front vehicle speed
sensor circuit.Go to step 11.
11 CHECK POOR CONTACT.Is there poor contact in front
vehicle speed sensor circuit?Repair the poor
contact.Replace the TCM.
trol Module
(TCM).> Step Check Yes No

4AT(H4DOTC)-60
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
2 CHECK HARNESS CONNECTOR BETWEEN
TCM AND ECM.
Measure the resistance of harness between
TCM connector and chassis ground.
Connector & terminal
(B55) No. 13 — Chassis ground:Is the resistance more than 1
MΩ?Go to step 3.Repair the short
circuit in harness
between TCM and
ECM connector.
3 PREPARE SUBARU SELECT MONITOR.Do you have a Subaru Select
Monitor?Go to step 5.Go to step 4.
4 CHECK INPUT SIGNAL FOR TCM.
1) Connect the connectors to TCM and ECM.
2) Turn the ignition switch to ON (engine OFF).
3) Measure the voltage between TCM con-
nector and chassis ground.
Connector & terminal
(B55) No. 13 (+) — Chassis ground (
−):Is the voltage less than 1 V? Even if the POWER
indicator light was
blinking, the circuit
has returned to a
normal condition at
this time. A tempo-
rary poor contact of
the connector or
harness may be the
cause. Repair the
harness or connec-
tor of TCM and
ECM.Go to step 6.
5 CHECK INPUT SIGNAL FOR TCM USING
SUBARU SELECT MONITOR.
1) Connect the connectors to TCM and ECM.
2) Connect the Subaru Select Monitor to data
link connector.
3) Start the engine and turn Subaru Select
Monitor switch to ON.
4) Idle the engine.
5) Read the data of engine speed using Sub-
aru Select Monitor.
Display shows the engine speed signal value
sent from ECM.Is the revolution value same as
tachometer reading shown on
combination meter?Even if the POWER
indicator light was
blinking, the circuit
has returned to a
normal condition at
this time. A tempo-
rary poor contact of
the connector or
harness may be the
cause. Repair the
harness or connec-
tor of TCM and
ECM.Go to step 6.
6 CHECK POOR CONTACT.Is there poor contact in engine
speed signal circuit?Repair the poor
contact.Go to step 7.
7 CONFIRM DTC P0725.
Replace the ECM with a new one. Does the DTC appear again,
after memory has been
cleared?Replace the TCM.
trol Module
(TCM).>Replace the ECM.
Engine Control
Module (ECM).> Step Check Yes No