SUBARU FORESTER 2004 Service Repair Manual

4AT(H4SO)-32
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure for Subaru Select Monitor Communication
11.Diagnostic Procedure for Subaru Select Monitor Communication
A: COMMUNICATION FOR INITIALIZING IMPOSSIBLE
DIAGNOSIS:
Faulty harness connector
TROUBLE SYMPTOM:
Select monitor communication failure
WIRING DIAGRAM:
AT-00572
B40B11
F45
B54 A:B56
B11
T4
B40
DATA LINK
CONNECTOR
TCM C:
1 1
2 2
3 3
4 4
5
56
6778
8
9 9
13 14 15
20 19 171610 10
11 11
12
13 14 15 16 12
BATTERY
E
E
F45
B62
NO.4
NO.11
SBF-4 SBF-1 LHD
LHD
IGNITION
SWITCH
C1
A23
A24
C15
C24
18
123 4 567
8 9 10 12 13 14 15 1611
1234 5 6 7 8 9
10 11 12 13 14 15 16 17 18
19 20 21 22 23 241234 5 6 7 8 9
10 11 12 13 14 15 16 17 18
19 20 21 22 23 24
RHD
RHD
9
1
10
6
12
13
SBF-5
F44
B61
LHD
RHD
7
LHD
RHD
B21
E216
E
B21
1234
5678
9
10 11 12
13 14 15 16
12345678
F44
A21
C19
16
24
B300
LINE END
CHECK
CONNECTOR
: LHD MODEL
: RHD MODELLHD
RHD
123
456
B300
TRANSMISSION
B56C:B54A:

4AT(H4SO)-33
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure for Subaru Select Monitor Communication
Step Check Yes No
1 CHECK SUBARU SELECT MONITOR POW-
ER SUPPLY CIRCUIT.
Measure the voltage between data link con-
nector and chassis ground.
Connector & terminal
(B40) No. 1 (+) — Chassis ground (
−):Is the voltage more than 10 V? Go to step 2.Repair the har-
ness and connec-
tor between battery
and data link con-
nector, and poor
contact in coupling
connector.
2 CHECK SUBARU SELECT MONITOR
GROUND CIRCUIT.
Measure the resistance of harness between
data link connector and chassis ground.
Connector & terminal
(B40) No. 12 — Chassis ground:
(B40) No. 13 — Chassis ground:Is the resistance less than 1
Ω?Go to step 3.Repair the open
circuit in harness
between data link
connector and
ground terminal,
and poor contact
in coupling con-
nector.
3 CHECK COMMUNICATION OF SELECT
MONITOR.
1) Turn the ignition switch to ON.
2) Using the Subaru Select Monitor, check
whether communication to engine systems can
be executed normally.Are the contents of engine sys-
tem displayed on Subaru
Select Monitor?Go to step 8.Go to step 4.
4 CHECK COMMUNICATION OF SELECT
MONITOR.
1) Turn the ignition switch to OFF.
2) Disconnect the TCM connector.
3) Check whether communication to engine
systems can be executed normally.Are the contents of engine sys-
tem displayed on Subaru
Select Monitor?Go to step 6.Go to step 5.
5 CHECK COMMUNICATION OF SELECT
MONITOR.
1) Turn the ignition switch to OFF.
2) Connect the TCM connector.
3) Disconnect the ECM connector.
4) Check whether communication to transmis-
sion systems can be executed normally.Are the contents of transmis-
sion displayed on Subaru
Select Monitor?Inspect the ECM. Go to step 6.
6 CHECK HARNESS CONNECTOR BETWEEN
EACH CONTROL MODULE AND DATA LINK
CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the TCM, ECM.
3) Measure the resistance between data link
connector and chassis ground.
Connector & terminal
(B40) No. 10 — Chassis ground:
(B40) No. 6 — Chassis ground:Is the resistance more than 1
MΩ?Go to step 7.Repair the har-
ness and connec-
tor between each
control module and
data link connector.
7 CHECK OUTPUT SIGNAL FOR TCM.
1) Turn the ignition switch to ON.
2) Measure the voltage between data link con-
nector and chassis ground.
Connector & terminal
(B40) No. 10 (+) — Chassis ground (
−):Is the voltage more than 1 V? Repair the har-
ness and connec-
tor between each
control module
and data link con-
nector.Go to step 8.
8 CHECK HARNESS/CONNECTOR BETWEEN
TCM AND DATA LINK CONNECTOR.
Measure the resistance between TCM connec-
tor and data link connector.
Connector & terminal
(B56) No. 15 — (B40) No. 10:Is the resistance less than 0.5
Ω?Go to step 9.Repair the harness
and connector
between TCM and
data link connector.

4AT(H4SO)-34
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure for Subaru Select Monitor Communication
9 CHECK HARNESS/CONNECTOR BETWEEN
TCM AND DATA LINK CONNECTOR.
Measure the resistance between TCM and
data link connector.
Connector & terminal
(B56) No. 24 — (B40) No. 6:Is the resistance more than 1
MΩ?Go to step 10.Repair the harness
and connector
between TCM and
data link connector.
10 CHECK INSTALLATION OF TCM CONNEC-
TOR.
Turn the ignition switch to OFF.Is the TCM connector inserted
into TCM?Go to step 11.Insert the TCM
connector into
TCM.
11 CHECK POOR CONTACT IN CONNECTORS.Is there poor contact in control
module and data link connec-
tor?Repair the poor
contact.Replace the TCM.
<Ref. to 4AT-77,
Transmission Con-
trol Module
(TCM).> Step Check Yes No

4AT(H4SO)-35
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
List of Diagnostic Trouble Code (DTC)
12.List of Diagnostic Trouble Code (DTC)
A: LIST
DTC Item Content of diagnosis Index
11 Engine speed signalDetects open or shorted input
signal circuit.<Ref. to 4AT(H4SO)-36, DTC 11 ENGINE SPEED
SIGNAL, Diagnostic Procedure with Diagnostic
Trouble Code (DTC).>
27 ATF temperature sensorDetects open or shorted input
signal circuit.<Ref. to 4AT(H4SO)-38, DTC 27 ATF TEMPERA-
TURE SENSOR, Diagnostic Procedure with Diag-
nostic Trouble Code (DTC).>
31 Throttle position sensorDetects open or shorted input
signal circuit.<Ref. to 4AT(H4SO)-41, DTC 31 THROTTLE
POSITION SENSOR, Diagnostic Procedure with
Diagnostic Trouble Code (DTC).>
33Front vehicle speed
sensorDetects open or shorted input
signal circuit.<Ref. to 4AT(H4SO)-45, DTC 33 FRONT VEHI-
CLE SPEED SENSOR, Diagnostic Procedure with
Diagnostic Trouble Code (DTC).>
36Torque converter tur-
bine speed sensorDetects open or shorted input
signal circuit.<Ref. to 4AT(H4SO)-49, DTC 36 TORQUE CON-
VERTER TURBINE SPEED SENSOR, Diagnostic
Procedure with Diagnostic Trouble Code (DTC).>
38 Torque control signalDetects open or shorted input
signal circuit.<Ref. to 4AT(H4SO)-52, DTC 38 TORQUE CON-
TROL SIGNAL, Diagnostic Procedure with Diag-
nostic Trouble Code (DTC).>
45Intake manifold pres-
sure signalDetects open or shorted input
signal circuit.<Ref. to 4AT(H4SO)-54, DTC 45 INTAKE MANI-
FOLD PRESSURE SIGNAL, Diagnostic Proce-
dure with Diagnostic Trouble Code (DTC).>
71 Shift solenoid 1Detects open or shorted out-
put signal circuit.<Ref. to 4AT(H4SO)-56, DTC 71 SHIFT SOLE-
NOID 1, Diagnostic Procedure with Diagnostic
Trouble Code (DTC).>
72 Shift solenoid 2Detects open or shorted out-
put signal circuit.<Ref. to 4AT(H4SO)-59, DTC 72 SHIFT SOLE-
NOID 2, Diagnostic Procedure with Diagnostic
Trouble Code (DTC).>
73Low clutch timing sole-
noidDetects open or shorted out-
put signal circuit.<Ref. to 4AT(H4SO)-62, DTC 73 LOW CLUTCH
TIMING SOLENOID, Diagnostic Procedure with
Diagnostic Trouble Code (DTC).>
742-4 brake timing sole-
noidDetects open or shorted out-
put signal circuit.<Ref. to 4AT(H4SO)-65, DTC 74 2-4 BRAKE TIM-
ING SOLENOID, Diagnostic Procedure with Diag-
nostic Trouble Code (DTC).>
75Line pressure duty sole-
noidDetects open or shorted out-
put signal circuit.<Ref. to 4AT(H4SO)-68, DTC 75 LINE PRES-
SURE DUTY SOLENOID, Diagnostic Procedure
with Diagnostic Trouble Code (DTC).>
76 2-4 brake duty solenoidDetects open or shorted out-
put signal circuit.<Ref. to 4AT(H4SO)-71, DTC 76 2-4 BRAKE
DUTY SOLENOID, Diagnostic Procedure with
Diagnostic Trouble Code (DTC).>
77 Lock-up duty solenoidDetects open or shorted out-
put signal circuit.<Ref. to 4AT(H4SO)-74, DTC 77 LOCK-UP DUTY
SOLENOID, Diagnostic Procedure with Diagnostic
Trouble Code (DTC).>
79 Transfer duty solenoidDetects open or shorted out-
put signal circuit.<Ref. to 4AT(H4SO)-78, DTC 79 TRANSFER
DUTY SOLENOID, Diagnostic Procedure with
Diagnostic Trouble Code (DTC).>
93Rear vehicle speed
sensorDetects open or shorted input
signal circuit.<Ref. to 4AT(H4SO)-81, DTC 93 REAR VEHICLE
SPEED SENSOR, Diagnostic Procedure with
Diagnostic Trouble Code (DTC).>

4AT(H4SO)-36
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
13.Diagnostic Procedure with Diagnostic Trouble Code (DTC)
A: DTC 11 ENGINE SPEED SIGNAL
DTC DETECTING CONDITION:
The engine speed input signal circuit is open or shorted.
TROUBLE SYMPTOM:
 No lock-up (after engine warm-up).
 The POWER indicator light remains on when vehicle speed is “0”.
WIRING DIAGRAM:
AT-01824
10
17
B55
B134
ECM
B134
B55 TCM
123 4
5
6
789
10 1112
13 14 15 16 17 18
192012
910 11 21
242534
12 13
2627161718
303114 15
28
297
8
22
23
343556
19 20
32
33
21
2223 24

4AT(H4SO)-37
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK HARNESS CONNECTOR BETWEEN
TCM AND ECM.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from TCM and
ECM.
3) Measure the resistance of harness
between TCM and ECM connector.
Connector & terminal
(B55) No. 17 — (B134) No. 10:Is the resistance less than 1
Ω?Go to step 2.Repair the open
circuit in harness
between TCM and
ECM connector.
2 CHECK HARNESS CONNECTOR BETWEEN
TCM AND ECM.
Measure the resistance of harness between
TCM connector and chassis ground.
Connector & terminal
(B55) No. 17 — 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. 17 (+) — Chassis ground (
−):Is the voltage more than 10.5
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 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) Warm-up the engine until engine coolant
temperature is above 80°C (176°F).
5) Idle the engine.
6) 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 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 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 11.Replace the ECM with a new
one. Does the DTC 11 appear
again, after memory has been
cleared?Replace the TCM.
<Ref. to 4AT-77,
Transmission Con-
trol Module
(TCM).>Replace the ECM.
<Ref. to
FU(H4SO)-44,
Engine Control
Module (ECM).>

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

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. <Ref. to 4AT-
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. <Ref. to 4AT-
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.

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.
<Ref. to 4AT-77,
Transmission Con-
trol Module
(TCM).> Step Check Yes No

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: