Page 2497 of 2870
4AT(H4SO)-38
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
B: DTC 27 ATF TEMPERATURE SENSOR
DTC DETECTING CONDITION:
The input signal circuit of TCM to ATF temperature sensor is open or shorted.
TROUBLE SYMPTOM:
Excessive shift shock.
WIRING DIAGRAM:
AT-00776
11
20 11
12 ATF TEMPERATURE
SENSOR
B54
B11
T4 TCM
B11TRANSMISSION
125678
131415169101112
34
17181920
B54
1234
10
11 12
19 20 21135614 1578916 17 18
22 23 24
Page 2498 of 2870

4AT(H4SO)-39
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK HARNESS CONNECTOR BETWEEN
TCM AND ATF TEMPERATURE SENSOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from transmis-
sion and TCM.
3) Measure the resistance of harness
between TCM and transmission connector.
Connector & terminal
(B54) No. 20 — (B11) No. 12:Is the resistance less than 1
Ω?Go to step 2.Repair the open
circuit in harness
between TCM and
transmission con-
nector.
2 CHECK HARNESS CONNECTOR BETWEEN
TCM AND ATF TEMPERATURE SENSOR.
Measure the resistance of harness between
TCM and transmission connector.
Connector & terminal
(B54) No. 11 — (B11) No. 11: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 ATF TEMPERATURE SENSOR.
Measure the resistance of harness between
TCM connector and chassis ground.
Connector & terminal
(B54) No. 20 — Chassis ground:Is the resistance more than 1
MΩ?Go to step 4.Repair the short
circuit in harness
between TCM and
transmission con-
nector.
4 CHECK HARNESS CONNECTOR BETWEEN
TCM AND ATF TEMPERATURE SENSOR.
Measure the resistance of harness between
TCM connector and chassis ground.
Connector & terminal
(B54) No. 11 — 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 ATF TEMPERATURE SENSOR.
1) Turn the ignition switch to OFF.
2) Connect the connectors to transmission
and TCM.
3) Turn the ignition switch to ON and start
engine.
4) Warm-up the transmission until ATF tem-
perature reaches to 80°C (176°F).
NOTE:
If ambient temperature is below 0°C (32°F),
drive the vehicle until ATF reaches its operating
temperature.
5) Disconnect the connector from transmis-
sion.
6) Measure the resistance between transmis-
sion connector terminals.
Connector & terminal
(T4) No. 11 — No. 12:Is the resistance 275 — 375
Ω?Go to step 6.Replace the ATF
temperature sen-
sor.
71, Shift Sole-
noids, Duty Sole-
noids and ATF
Temperature Sen-
sor.>
6 CHECK ATF TEMPERATURE SENSOR.
1) Turn the ignition switch to ON (engine
OFF).
2) Measure the resistance between transmis-
sion connector terminals.
Connector & terminal
(T4) No. 11 — No. 12:Does the resistance value
increase while ATF tempera-
ture decreases? Go to step 7.Replace the ATF
temperature sen-
sor.
71, Shift Sole-
noids, Duty Sole-
noids and ATF
Temperature Sen-
sor.>
7 PREPARE SUBARU SELECT MONITOR.Do you have a Subaru Select
Monitor?Go to step 9.Go to step 8.
Page 2499 of 2870

4AT(H4SO)-40
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
8 CHECK INPUT SIGNAL FOR TCM.
1) Connect the connector to transmission.
2) Warm-up the transmission until ATF tem-
perature is about 80°C (176°F).
N
OTE:
If ambient temperature is below 0°C (32°F),
drive the vehicle until ATF reaches its operating
temperature.
3) Measure the voltage between TCM con-
nector terminal.
Connector & terminal
(B54) No. 11 (+) — No. 20 (
−):Is the voltage 0.4 — 0.9 V? Even if the
POWER indicator
light was blinking,
the circuit has
returned to a nor-
mal condition at
this time. Tempo-
rary poor contact
of the connector or
harness may be
the cause. Repair
the harness or
contact in ATF
temperature sen-
sor and transmis-
sion connector.Go to step 10.
9 CHECK INPUT SIGNAL FOR TCM USING
SUBARU SELECT MONITOR.
1) Connect the connector to transmission.
2) Turn the ignition switch to ON (engine OFF).Does the ATF temperature
gradually decrease?Even if the
POWER indicator
light was blinking,
the circuit has
returned to a nor-
mal condition at
this time. Tempo-
rary poor contact
of the connector or
harness may be
the cause. Repair
the harness or
contact in ATF
temperature sen-
sor and transmis-
sion connector.Go to step 10.
10 CHECK POOR CONTACT.Is there poor contact in ATF
temperature sensor circuit?Repair the poor
contact.Replace the TCM.
Transmission Con-
trol Module
(TCM).> Step Check Yes No
Page 2500 of 2870

4AT(H4SO)-41
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
C: DTC 31 THROTTLE POSITION SENSOR
DTC DETECTING CONDITION:
The input signal circuit of throttle position sensor is open or shorted.
TROUBLE SYMPTOM:
Shift point too high or too low
Excessive shift shock
Tight corner braking phenomenon
WIRING DIAGRAM:
AT-01825
B134B136B135
12
910 11 21
242512
893
10
212212
8
93
105
1711
2212 13
2314
2415
25
204
16
26 2167
1819
272834
12 13
2627161718
303114 15
28
2978
22
23
343556
19 20
32
33
B54B122
1234
56789
10 1112
13 14 15 16 17 18
192021
2223 24
18131415
25
2611 12
23246
7
192045
16 17
B22
1
234
56
78
9
1314
15
20
19 1716 10 11
12
18
B21
E13
B122
B21
B134B54 TCM
A:B135 B:
B136ECM
C:
E2
B22
E3
E13
13 1415
16
12 34
12 3456 78
9
10
11
12
B13
B3
15
13816
14B19
4
3
22
3
C26D14B21C16C5A35A7
EE
2
1
12
11
9
SHIELD AND
THROTTLE
POSITION SENSORSENSOR GROUND
JOINT CONNECTOR
B122: RHD
: LHD
12
893
10
1813141511 1267
19204
5
16 17
B137
B137 D:
12345678
D:
B:
A: C:
Page 2501 of 2870

4AT(H4SO)-42
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK ENGINE GROUND TERMINALS.Have engine ground terminals
been tightened?Go to step 2.Tighten the engine
ground terminals.
2 CHECK GROUND CIRCUIT OF ECM.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM.
3) Measure the resistance of harness
between ECM and engine ground.
Connector & terminal
(B134) No. 7 — Engine ground:
(B134) No. 35 — Engine ground:
(B135) No. 21 — Engine ground:
(B136) No. 26 — Engine ground:
(B136) No. 5 — Engine ground:
(B136) No. 16 — Engine ground:
(B137) No. 14 — Engine ground:Is the resistance less than 5
Ω?Go to step 3.Repair the open
circuit in harness
between ECM
connector and
engine grounding
terminal.
3 CHECK THROTTLE POSITION SENSOR.
1) Disconnect the connector from throttle
position sensor.
2) Measure the resistance between throttle
position sensor connector receptacle’s terminals.
Te r m i n a l s
No. 4 — No. 2:Is the resistance 3.0 — 4.2
kΩ?Go to step 4.Replace the throt-
tle position sensor.
4 CHECK THROTTLE POSITION SENSOR.
Measure the resistance between throttle posi-
tion sensor connector receptacle’s terminals.
Te r m i n a l s
No. 2 — No. 3:Is the resistance 0.35 — 0.5
kΩ?Go to step 5.Replace the throt-
tle position sensor.
5 CHECK HARNESS CONNECTOR BETWEEN
TCM AND THROTTLE POSITION SENSOR.
1) Disconnect the connector from TCM.
2) Measure the resistance of harness
between TCM and throttle position sensor con-
nector.
Connector & terminal
(B54) No. 3 — (E13) No. 3:Is the resistance less than 1
Ω?Go to step 6.Repair the open
circuit in harness
between TCM and
throttle position
sensor connector,
and poor contact
in coupling con-
nector.
6 CHECK HARNESS CONNECTOR BETWEEN
TCM AND THROTTLE POSITION SENSOR.
Measure the resistance of harness between
TCM and throttle position sensor connector.
Connector & terminal
(B54) No. 2 — (E13) No. 4:Is the resistance less than 1
Ω?Go to step 7.Repair the open
circuit in harness
between TCM and
throttle position
sensor connector,
and poor contact
in coupling con-
nector.
7 CHECK HARNESS CONNECTOR BETWEEN
TCM AND THROTTLE POSITION SENSOR.
Measure the resistance of harness between
TCM connector and chassis ground.
Connector & terminal
(B54) No. 3 — Chassis ground:Is the resistance more than 1
MΩ?Go to step 8.Repair the short
circuit in harness
between TCM and
throttle position
sensor connector.
8 CHECK HARNESS CONNECTOR BETWEEN
TCM AND THROTTLE POSITION SENSOR.
Measure the resistance of harness between
TCM connector and chassis ground.
Connector & terminal
(B54) No. 2 — Chassis ground:Is the resistance more than 1
MΩ?Go to step 9.Repair the short
circuit in harness
between TCM and
throttle position
sensor connector.
Page 2502 of 2870

4AT(H4SO)-43
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
9 CHECK HARNESS CONNECTOR BETWEEN
TCM AND ECM.
Measure the resistance of harness between
TCM and ECM connector.
Connector & terminal
(B54) No. 3 — (B135) No. 13:Is the resistance less than 1
Ω?Go to step 10.Repair the open
circuit in harness
between TCM and
ECM connector.
10 CHECK HARNESS CONNECTOR BETWEEN
TCM AND ECM.
Measure the resistance of harness between
TCM and ECM connector.
Connector & terminal
(B54) No. 2 — (B135) No. 19:Is the resistance less than 1
Ω?Go to step 11.Repair the open
circuit in harness
between TCM and
ECM connector.
11 PREPARE SUBARU SELECT MONITOR.Do you have a Subaru Select
Monitor?Go to step 14.Go to step 12.
12 CHECK INPUT SIGNAL FOR TCM.
1) Connect the connectors to TCM, throttle
position sensor and ECM.
2) Turn the ignition switch to ON (engine
OFF).
3) Close the throttle completely.
4) Measure the voltage between TCM con-
nector and chassis ground.
Connector & terminal
(B54) No. 3 (+) — Chassis ground (
−):Is the voltage 0.2 — 1.0 V? Go to step 13.Go to step 18.
13 CHECK INPUT SIGNAL FOR TCM.
1) Open the throttle completely.
2) Measure the voltage between TCM con-
nector and chassis ground.
Connector & terminal
(B54) No. 3 (+) — Chassis ground (
−):Is the voltage 4.2 — 4.7 V? Go to step 16.Go to step 18.
14 CHECK INPUT SIGNAL FOR TCM USING
SUBARU SELECT MONITOR.
1) Connect the connectors to TCM, throttle
position sensor and ECM.
2) Connect the Subaru Select Monitor to data
link connector.
3) Turn the ignition switch to ON (engine
OFF).
4) Turn the Subaru Select Monitor switch to
ON.
5) Throttle fully closed.
6) Read the data of throttle position sensor
using Subaru Select Monitor.
Throttle position sensor input signal is indi-
cated.Is the value voltage 0.2 — 1.0
V?Go to step 15.Go to step 18.
15 CHECK INPUT SIGNAL FOR TCM USING
SUBARU SELECT MONITOR.
Throttle fully open.
N
OTE:
Must be changed correspondingly with the ac-
celerator pedal operation (from “released” to
“depressed” position).Is the value voltage 4.2 — 4.7
V?Go to step 17.Go to step 18. Step Check Yes No
Page 2503 of 2870

4AT(H4SO)-44
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
16 CHECK INPUT SIGNAL FOR TCM (THROT-
TLE POSITION SENSOR POWER SUPPLY).
Measure the voltage between TCM connector
and chassis ground.
Connector & terminal
(B54) No. 2 (+) — Chassis ground (
−):Is the voltage 4.8 — 5.3 V? Even if the
POWER indicator
light was blinking,
the circuit has
returned to a nor-
mal condition at
this time. A tempo-
rary poor contact
of the connector or
harness may be
the cause. Repair
the harness or
connector in throt-
tle position sensor
circuit.Go to step 18.
17 CHECK INPUT SIGNAL FOR TCM USING
SUBARU SELECT MONITOR (THROTTLE
POSITION SENSOR POWER SUPPLY).
Read the data of throttle position sensor power
supply using Subaru Select Monitor.
Throttle position sensor power supply volt-
age is indicated.Is the value voltage 4.8 — 5.3
V?Even if the
POWER indicator
light was blinking,
the circuit has
returned to a nor-
mal condition at
this time. A tempo-
rary poor contact
of the connector or
harness may be
the cause. Repair
the harness or
connector in throt-
tle position sensor
circuit.Go to step 18.
18 CHECK POOR CONTACT.Is there poor contact in throttle
position sensor circuit?Repair the poor
contact.Replace the TCM.
Transmission Con-
trol Module
(TCM).> Step Check Yes No
Page 2504 of 2870
4AT(H4SO)-45
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
D: DTC 33 FRONT VEHICLE SPEED SENSOR
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.