SUBARU FORESTER 2004 Service Repair Manual

4AT(H4SO)-52
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
F: DTC 38 TORQUE CONTROL SIGNAL
DTC DETECTING CONDITION:
The signal circuit is open or shorted.
TROUBLE SYMPTOM:
Excessive shift shock.
WIRING DIAGRAM:
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
(B56) No. 14 — (B136) No. 18:
(B56) No. 5 — (B136) No. 1Is 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
(B56) No. 14 — Chassis ground:
(B56) No. 5 — Chassis ground:Is the resistance more than 1
MΩ?Go to step 3.Repair the short
circuit in harness
between TCM and
ECM connector.
AT-01827
18
114
5
B56
B136
B136ECM
B56
TCM
1234
56789
10 1112
13 14 15 16 17 18
1920451712
89
20
213
1011 12
13
222314 15
242516
2667
18
19
2728
21
2223 24
2930

4AT(H4SO)-53
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
3 CHECK OUTPUT SIGNAL EMITTED FROM
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 terminals.
Connector & terminal
(B56) No. 14 (+) — Chassis ground (
−):
(B56) No. 5 (+) — Chassis ground (
−):Is the voltage more than 4.8 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 4.
4 CHECK POOR CONTACT.Is there poor contact in torque
control signal circuit?Repair the poor
contact.Go to step 5.
5 CHECK GROUND LINE BETWEEN TRANS-
MISSION AND BODY.
Check installing condition of the ground line in
transmission and body.Is there any dirt or rust at the
ground line installing point?Remove dirt and
rust.Go to step 6.
6 CHECK GROUND LINE BETWEEN TRANS-
MISSION AND BODY.
Check installing condition of the ground line in
transmission and body.Is the tightening torque value
13 N⋅m (1.3 kgf-m, 9.4 ft-lb)?Go to step 7.Tighten to the
specified torque.
7 CHECK GROUND LINE INSIDE TRANSMIS-
SION.
1) Drain the ATF and remove oil pan.
2) Check the tightening torque value of ground
line installing bolt.Is the tightening torque value 8
N⋅m (0.8 kgf-m, 5.8 ft-lb)?Go to step 8.Tighten to the
specified torque.
8 CHECK GROUND CIRCUIT OF ECM.
<Ref. to 4AT(H4SO)-41, DTC 31 THROTTLE
POSITION SENSOR, Diagnostic Procedure
with Diagnostic Trouble Code (DTC).>Is there any trouble? Repair the ground
terminal and/or
ground circuit of
ECM.Go to step 9.
9 RECHECK OUTPUT SIGNAL EMITTED
FROM TCM.
Measure the voltage between TCM connector
and chassis ground.
Connector & terminal
(B56) No. 14 (+) — Chassis ground (
−):
(B56) No. 5 (+) — Chassis ground (
−):Is the voltage more than 4 V? Replace the TCM.
<Ref. to 4AT-77,
Transmission Con-
trol Module
(TCM).>Replace the ECM. Step Check Yes No

4AT(H4SO)-54
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
G: DTC 45 INTAKE MANIFOLD PRESSURE SIGNAL
DTC DETECTING CONDITION:
The input signal circuit of TCM from ECM is open or shorted.
TROUBLE SYMPTOM:
Excessive shift shock.
WIRING DIAGRAM:
Step Check Yes No
1 CHECK ENGINE GROUND TERMINALS AND
GROUND CIRCUIT OF ECM
<Ref. to 4AT(H4SO)-41, DTC 31 THROTTLE
POSITION SENSOR, Diagnostic Procedure
with Diagnostic Trouble Code (DTC).>Is there any trouble? Repair the ground
terminal and/or
ground circuit of
ECM.Go to step 2.
2 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
(B54) No. 1 — (B137) No. 2:Is the resistance less than 1
Ω?Go to step 3.Repair the open
circuit in harness
between TCM and
ECM connector.
3 CHECK HARNESS CONNECTOR BETWEEN
TCM AND ECM.
Measure the resistance of harness between
TCM connector and chassis ground.
Connector & terminal
(B54) No. 1 — Chassis ground:Is the resistance more than 1
MΩ?Go to step 4.Repair the short
circuit in harness
between TCM and
ECM connector.
4 PREPARE SUBARU SELECT MONITOR.Do you have a Subaru Select
Monitor?Go to step 6.Go to step 5.
AT-00582
2
1
B54
B54
B137
B137ECM
TCM
1234
56789
10 1112
13 14 15 16 17 18
19204
5
17
12
89
20
3
1011 12
1314 151667
18
19
21
2223 24

4AT(H4SO)-55
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
5 CHECK INPUT SIGNAL FOR TCM.
1) Connect the connectors to TCM and ECM.
2) Start the engine, and warm-up the trans-
mission until ATF temperature is above 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) Idle the engine.
4) Measure the voltage between TCM con-
nector and chassis ground.
Connector & terminal
(B54) No. 1 (+) — Chassis ground (
−):Is the voltage 0.4 — 1.6 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 7.
6 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 intake manifold pressure
signal using Subaru Select Monitor.
 Display shows the intake manifold pressure
signal value sent from ECM.Is the voltage 0.4 — 1.6 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 7.
7 CHECK POOR CONTACT.Is there poor contact in intake
manifold pressure signal cir-
cuit?Repair the poor
contact.Replace the TCM.
<Ref. to 4AT-77,
Transmission Con-
trol Module
(TCM).> Step Check Yes No

4AT(H4SO)-56
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
H: DTC 71 SHIFT SOLENOID 1
DTC DETECTING CONDITION:
The output signal circuit of shift solenoid 1 is open or shorted.
TROUBLE SYMPTOM:
Does not shift.
WIRING DIAGRAM:
Step Check Yes No
1 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 shift solenoid 1 connector.
Connector & terminal
(B54) No. 22 — (B11) No. 1:Is the resistance less than 1
Ω?Go to step 2.Repair the open
circuit in harness
between TCM and
transmission con-
nector.
AT-00583

22
TRANSMISSION
B54TCM
AT 5
1T4
B11
SHIFT
SOLENOID 1
B54
12
789 56 3410 11 12
19 20 2113 14 15 16 17 18
22
23
24
B11
125678
131415169101112
34
17181920

4AT(H4SO)-57
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
2 CHECK HARNESS CONNECTOR BETWEEN
TCM AND TRANSMISSION.
Measure the resistance of harness between
TCM connector and chassis ground.
Connector & terminal
(B54) No. 22 — Chassis ground:Is the resistance more than 1
MΩ?Go to step 3.Repair the short
circuit in harness
between TCM and
transmission con-
nector.
3 CHECK SHIFT SOLENOID 1.
Measure the resistance between transmission
connector terminals.
Connector & terminal
(T4) No. 1 — No. 16:Is the resistance 10 — 16 Ω? Go to step 4.Go to step 7.
4 CHECK OUTPUT SIGNAL EMITTED FROM
TCM.
1) Connect the connectors to TCM and trans-
mission.
2) Turn the ignition switch to ON (engine
OFF).
3) Move the select lever to “D” range.
4) Measure the voltage between TCM con-
nector and chassis ground.
Connector & terminal
(B54) No. 22 (+) — Chassis ground (
−):Is the voltage more than 9 V? Go to step 5.Go to step 6.
5 CHECK OUTPUT SIGNAL EMITTED FROM
TCM.
1) Turn the HOLD mode switch to ON.
2) Measure the voltage between TCM con-
nector and chassis ground.
Connector & terminal
(B54) No. 22 (+) — Chassis ground (
−):Is the voltage less than 1 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
contact in TCM.Go to step 6.
6 CHECK POOR CONTACT.Is there poor contact in shift
solenoid 1 circuit?Repair poor con-
tact.Replace the TCM.
<Ref. to 4AT-77,
Transmission Con-
trol Module
(TCM).>
7 CHECK SHIFT SOLENOID 1 (IN TRANSMIS-
SION).
1) Remove the transmission connector from
bracket.
2) Lift-up or raise the vehicle and support with
rigid rack.
NOTE:
Raise all wheels off ground.
3) Drain the ATF.
CAUTION:
Do not drain the ATF until it cools down.
4) Remove the oil pan, and disconnect con-
nector from shift solenoid 1.
5) Measure the resistance between shift sole-
noid 1 connector and transmission ground.
Te r m i n a l s
No. 1 — Transmission ground:Is the resistance 10 — 16 Ω? Go to step 8.Replace the shift
solenoid 1. <Ref.
to 4AT-71, Shift
Solenoids, Duty
Solenoids and ATF
Temperature Sen-
sor.> Step Check Yes No

4AT(H4SO)-58
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
8 CHECK HARNESS CONNECTOR BETWEEN
SHIFT SOLENOID 1 AND TRANSMISSION.
Measure the resistance of harness between
shift solenoid 1 and transmission connector.
Connector & terminal
(T4) No. 1 — (AT5) No. 1:Is the resistance less than 1
Ω?Go to step 9.Repair the open
circuit in harness
between shift sole-
noid 1 and trans-
mission connector.
9 CHECK HARNESS CONNECTOR BETWEEN
SHIFT SOLENOID 1 AND TRANSMISSION.
Measure the resistance of harness between
shift solenoid 1 connector and transmission
ground.
Connector & terminal
(T4) No. 1 — Transmission ground:Is the resistance more than 1
MΩ?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 shift
solenoid 1 and
transmission.Repair the short
circuit harness
between shift sole-
noid 1 and trans-
mission connector. Step Check Yes No

4AT(H4SO)-59
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
I: DTC 72 SHIFT SOLENOID 2
DTC DETECTING CONDITION:
The output signal circuit of shift solenoid 2 is open or shorted.
TROUBLE SYMPTOM:
Does not shift.
WIRING DIAGRAM:
AT-00584
5
TRANSMISSION
B54TCM
AT 6
SHIFT
SOLENOID 2
B54
12
789 56 3410 11 12
19 20 2113 14 15 16
17 18
22
23
24
T4
B112
B11
125678
131415169101112
34
17181920

4AT(H4SO)-60
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 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 shift solenoid 2 connector.
Connector & terminal
(B54) No. 5 — (B11) No. 2: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 TRANSMISSION.
Measure the resistance of harness between
TCM connector and transmission ground.
Connector & terminal
(B54) No. 5 — Chassis ground:Is the resistance more than 1
MΩ?Go to step 3.Repair the short
circuit in harness
between TCM and
transmission con-
nector.
3 CHECK SHIFT SOLENOID 2.
Measure the resistance between transmission
connector terminals.
Connector & terminal
(T4) No. 2 — No. 16:Is the resistance 10 — 16 Ω? Go to step 4.Go to step 6.
4 CHECK OUTPUT SIGNAL EMITTED FROM
TCM.
1) Connect the connectors to TCM and trans-
mission.
2) Lift-up or raise the vehicle and support with
rigid rack.
N
OTE:
Raise all wheels off ground.
3) Start the engine and warm-up the transmis-
sion until ATF temperature is above 80°C
(176°F).
NOTE:
If ambient temperature is below 0°C (32°F),
drive the vehicle until ATF reaches its operating
temperature.
4) Move the selector lever to “D” range, and
slowly increase vehicle speed to 50 km/h (31
MPH).
NOTE:
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
clearance procedure of on-board diagnostics
system. <Ref. to ABS-23, Clear Memory
Mode.>
5) Measure the voltage between TCM con-
nector and chassis ground.
Connector & terminal
(B54) No. 5 (+) — Chassis ground (
−):Is the voltage less than 1 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 transmission.Go to step 5.
5 CHECK POOR CONTACT.Is there poor contact in shift
solenoid 2 circuit?Repair the poor
contact.Replace the TCM.
<Ref. to 4AT-77,
Transmission Con-
trol Module
(TCM).>

4AT(H4SO)-61
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
6 CHECK SHIFT SOLENOID 2 (IN TRANSMIS-
SION).
1) Remove the transmission connector from
bracket.
2) Drain the ATF.
CAUTION:
Do not drain the ATF until it cools down.
3) Remove the oil pan, and disconnect con-
nector from shift solenoid 2.
4) Measure the resistance between shift sole-
noid 2 connector and transmission ground.
Connector & terminal
No. 1 — Transmission ground:Is the resistance 10 — 16 Ω? Go to step 7.Replace the shift
solenoid 2 assem-
bly. <Ref. to 4AT-
71, Shift Sole-
noids, Duty Sole-
noids and ATF
Temperature Sen-
sor.>
7 CHECK HARNESS CONNECTOR BETWEEN
SHIFT SOLENOID 2 AND TRANSMISSION.
Measure the resistance of harness between
shift solenoid 2 and transmission connector.
Connector & terminal
(AT6) No. 1 — (T4) No. 2:Is the resistance less than 1
Ω?Go to step 8.Repair the open
circuit in harness
between shift sole-
noid 2 and trans-
mission connector.
8 CHECK HARNESS CONNECTOR BETWEEN
SHIFT SOLENOID 2 AND TRANSMISSION.
Measure the resistance of harness between
shift solenoid 2 connector and transmission
ground.
Connector & terminal
(T4) No. 2 — Transmission ground:Is the resistance more than 1
MΩ?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 shift
solenoid 2 and
transmission.Repair the short
circuit harness
between shift sole-
noid 2 and trans-
mission connector. Step Check Yes No