2004 SUBARU FORESTER turn signal

4AT(H4SO)-82
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 transmission connector.
Connector & terminal
(B55) No. 24 — (B11) No. 19: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 and transmission connector.
Connector & terminal
(B54) No. 19 — (B11) No. 20:Is the resistance less than 1
Ω?Go to step 3.Repair the open cir-
cuit in harness
between TCM and
transmission, and
poor contact in cou-
pling connector.
3 CHECK HARNESS CONNECTOR BETWEEN
TCM AND TRANSMISSION.
Measure the resistance of harness between
TCM and chassis ground.
Connector & terminal
(B55) No. 24 — 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 TRANSMISSION.
Measure the resistance of harness between
TCM and chassis ground.
Connector & terminal
(B54) No. 19 — 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 REAR VEHICLE SPEED SENSOR.
Measure the resistance between transmission
connector receptacle’s terminals.
Connector & terminal
(T4) No. 19 — No. 20:Is the resistance 450 — 650
Ω?Go to step 6.Replace the rear
vehicle speed sen-
sor. 59, Rear Vehicle
Speed Sensor.>
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) Lift-up or raise the vehicle and place rigid
rack.
N
OTE:
Raise all wheels off floor.
3) Start the engine and set vehicle in 20 km/h
(12 MPH) condition.
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
clearance procedure of on-board diagnostics
system. Mode.>
4) Measure the voltage between TCM con-
nector terminals.
Connector & terminal
(B55) No. 24 (+) — (B54) No. 19 (
−):Is the voltage more than AC 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 11.

4AT(H4SO)-83
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
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) Lift-up or raise the vehicle and place rigid
rack.
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
clearance procedure of on-board diagnostics
system. Mode.>Does the speedometer indica-
tion increase as the Subaru
Select Monitor data increases?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 11.
10 CHECK INPUT SIGNAL FOR TCM USING
OSCILLOSCOPE.
1) Connect the connectors to TCM and trans-
mission.
2) Lift-up or raise the vehicle and place rigid
rack.
NOTE:
Raise all wheels off floor.
3) Set the oscilloscope to TCM connector ter-
minals.
Connector & terminal
Positive probe; (B55) No. 24
Earth lead; (B54) No. 19
4) Start the engine and set vehicle in 20 km/h
(12 MPH) condition.
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. Mode.>
5) Measure the signal voltage indicated on
oscilloscope.Is the signal voltage more than
AC 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 11.
11 CHECK POOR CONTACT.Is there poor contact in rear
vehicle speed sensor circuit?Repair the poor
contact.Replace the TCM.
Transmission Con-
trol Module
(TCM).> Step Check Yes No

4AT(H4SO)-86
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure without Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK FWD SWITCH.
Connect the Subaru Select Monitor to data link
connector, and then change to LED display
screen.When the fuse is inserted to
FWD switch, does LED light
up?Go to step CHECK
BRAKE SWITCH.
4AT(H4SO)-88,
CHECK BRAKE
SWITCH, Diag-
nostic Procedure
without Diagnostic
Trouble Code
(DTC).>Go to step 2.
2 CHECK FWD 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. 22 — Chassis ground:Does the FWD indicator light
illuminate?Go to step 3.Inspect the combi-
nation meter.
Combination
Meter Assembly.>
3 CHECK HARNESS CONNECTOR BETWEEN
TCM AND FWD SWITCH.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from TCM and
FWD switch.
3) Measure the resistance of harness
between TCM and FWD switch connector.
Connector & terminal
(B55) No. 20 — (F27) No. 36:Is the resistance less than 1
Ω?Go to step 4.Repair the open
circuit in harness
between TCM and
FWD switch con-
nector.
4 CHECK HARNESS CONNECTOR BETWEEN
TCM AND FWD SWITCH.
Measure the resistance of harness connector
between TCM and body to make sure that cir-
cuit does not short.
Connector & terminal
(B55) No. 20 — Chassis ground:Is the resistance more than 1
MΩ?Go to step 5.Repair the short
circuit in harness
between TCM and
FWD switch con-
nector.
5 CHECK HARNESS CONNECTOR BETWEEN
FWD SWITCH AND CHASSIS GROUND.
Measure the resistance of harness between
FWD switch and chassis ground.
Connector & terminal
(F27) No. 35 — Chassis ground:Is the resistance less than 1
Ω?Go to step 6.Repair the open
circuit in harness
between FWD
switch connector
and chassis
ground.
6 CHECK INPUT SIGNAL FOR TCM.
1) Turn the ignition switch to OFF.
2) Connect the connector to TCM and FWD
switch.
3) Turn the ignition switch to ON.
4) Measure the signal voltage for TCM while
installing the fuse to FWD switch connector.
Connector & terminal
(B55) No. 20 (+) — Chassis ground (
−):Is the voltage less than 1 V? Go to step 7.Go to step 11.
7 CHECK INPUT SIGNAL FOR TCM.
Measure the signal voltage for TCM while
removing the fuse from FWD switch connector.
Connector & terminal
(B55) No. 20 (+) — Chassis ground (
−):Is the voltage 6 — 9.1 V? Go to step 8.Replace the TCM.
Transmission Con-
trol Module
(TCM).>

4AT(H4SO)-87
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure without Diagnostic Trouble Code (DTC)
8 CHECK HARNESS CONNECTOR BETWEEN
TCM AND COMBINATION METER.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from TCM and
combination meter.
3) Measure the resistance of harness
between TCM and combination meter.
Connector & terminal
(B56) No. 2 — (i11) No. 4: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 coupling con-
nector.
9 CHECK HARNESS CONNECTOR BETWEEN
TCM AND COMBINATION METER.
Measure the resistance of harness connector
between TCM and chassis ground.
Connector & terminal
(B56) No. 2 — Chassis ground:Is the resistance more than 1
MΩ?Go to step 10.Repair the short
circuit in harness
between TCM and
combination meter
connector.
10 CHECK OUTPUT SIGNAL EMITTED FROM
TCM.
1) Turn the ignition switch to OFF.
2) Connect the connector to TCM and combi-
nation meter.
3) Turn the ignition switch to ON.
4) Measure the signal voltage for TCM while
installing the fuse to FWD switch connector.
Connector & terminal
(B56) No. 2 (+) — Chassis ground (
−):Is the voltage less than 1 V? Go to step 11.Go to step 12.
11 CHECK OUTPUT SIGNAL EMITTED FROM
TCM.
Measure the signal voltage for TCM while
removing the fuse from FWD switch connector.
Connector & terminal
(B56) No. 2 (+) — Chassis ground (
−):Is the voltage 6 — 9.1 V? Go to step 12.Replace the TCM.
Transmission Con-
trol Module
(TCM).>
12 CHECK POOR CONTACT.Is there poor contact in FWD
switch circuit?Repair the poor
contact.Replace the TCM.
Transmission Con-
trol Module
(TCM).> Step Check Yes No

4AT(H4SO)-90
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure without Diagnostic Trouble Code (DTC)
4 CHECK KICK-DOWN SWITCH.
Measure the resistance for kick-down switch
when releasing the accelerator pedal.
Te r m i n a l s
No. 1 — No. 2:Is the resistance more than 1
MΩ?Go to step 5.Replace the kick-
down switch. to SP(H4SO)-4,
Accelerator
Pedal.>
5 CHECK HARNESS CONNECTOR BETWEEN
TCM AND KICK-DOWN SWITCH.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from kick-down
switch.
3) Measure the resistance of harness connec-
tor between TCM and kick-down switch.
Connector & terminal
(B55) No. 11 — (B129) No. 2:Is the resistance less than 1
Ω?Go to step 6.Repair the open
circuit in harness
between TCM and
kick-down switch.
6 CHECK HARNESS CONNECTOR BETWEEN
TCM AND KICK-DOWN SWITCH.
Measure the resistance of harness connector
between TCM and chassis ground.
Connector & terminal
(B55) No. 11 — Chassis ground:Is the resistance more than 1
MΩ?Go to step 7.Repair the short
circuit in harness
between TCM and
chassis ground.
7 CHECK INPUT SIGNAL FOR TCM.
1) Turn the ignition switch to OFF.
2) Connect the connector to kick-down switch.
3) Turn the ignition switch to ON (engine OFF).
4) Measure the signal voltage for TCM when
depressing the accelerator pedal.
Connector & terminal
(B55) No. 11 (+) — Chassis ground (
−):Is the voltage less than 1 V? Go to step 8.Go to step 9.
8 CHECK INPUT SIGNAL FOR TCM.
Measure the signal voltage for TCM when
releasing the accelerator pedal.
Connector & terminal
(B55) No. 11 (+) — Chassis ground (
−):Is the voltage more than 6.5 V? A temporary poor
contact of the con-
nector and har-
ness may be the
cause. Repair the
harness and con-
nector in TCM.Go to step 9.
9 CHECK POOR CONTACT.Is there poor contact? Repair the poor
contact.Replace the TCM.
Transmission Con-
trol Module
(TCM).> Step Check Yes No

4AT(H4SO)-94
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure without Diagnostic Trouble Code (DTC)
9 CHECK INPUT SIGNAL FOR TCM.
1) Connect the connectors to TCM and
POWER switch.
2) Turn the ignition switch to ON (engine OFF).
3) Measure the signal voltage for TCM while
turning POWER switch to OFF.
Connector & terminal
(B55) No. 23 (+) — Chassis ground (–):Is the voltage more than 10 V? Go to step 10.Replace the TCM.
Transmission Con-
trol Module
(TCM).>
10 CHECK INPUT SIGNAL FOR TCM.
Measure the signal voltage for TCM while turn-
ing POWER switch to ON.
Connector & terminal
(B55) No. 23 (+) — Chassis ground (–):Is the voltage less than 1 V? Go to step 11.Replace the TCM.
Transmission Con-
trol Module
(TCM).>
11 CHECK POOR CONTACT.Is there poor contact in
POWER switch circuit?Repair the poor
contact.A temporary poor
contact of the con-
nector or harness
or connector in
POWER switch cir-
cuit. Step Check Yes No

4AT(H4SO)-99
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure without Diagnostic Trouble Code (DTC)
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 connector
and chassis
ground, and poor
contact in cou-
pling 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. 1 — (T7) No. 9:Is the resistance less than 1
Ω?Go to step 24.Repair the open
circuit in harness
between TCM and
inhibitor switch
connector, and
poor contact in
coupling connec-
tor.
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) Move the select lever to “P” range.
5) Measure the voltage between TCM and
chassis ground.
Connector & terminal
(B55) No. 1 (+) — Chassis ground (–):Is the voltage less than 1 V? Go to step 25.Go to step 65.
25 CHECK INPUT SIGNAL FOR TCM.
1) Position the select lever to any other than
“P” range.
2) Measure the voltage between TCM and
chassis ground.
Connector & terminal
(B55) No. 1 (+) — Chassis ground (–):Is the voltage more than 8 V? Go to step 65.Replace the TCM.
Transmission Con-
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. IDI-10, Combina-
tion Meter Assem-
bly.>
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. 1 — (i10) No. 1: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 and chassis ground.
Connector & terminal
(B55) No. 1 — Chassis ground:Is the resistance less than 1
MΩ?Go to step 29.Repair the ground
short circuit in “P”
range circuit. Step Check Yes No

4AT(H4SO)-100
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure without Diagnostic Trouble Code (DTC)
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. 3 — (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) Move the select lever to “R” range.
5) Measure the voltage between TCM and
chassis ground.
Connector & terminal
(B55) No. 3 (+) — Chassis ground (–):Is the voltage less than 1 V? Go to step 31.Go to step 65.
31 CHECK INPUT SIGNAL FOR TCM.
1) Position the select lever to any other than
“R” range.
2) Measure the voltage between TCM and
chassis ground.
Connector & terminal
(B55) No. 3 (+) — Chassis ground (–):Is the voltage more than 8 V? Go to step 65.Replace the TCM.
Transmission Con-
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. 10, Combination
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. 3 — (i10) No. 2: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. 3 — 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. 14 — (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. Step Check Yes No