2004 SUBARU FORESTER light

4AT(H4SO)-80
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
8 CHECK OUTPUT SIGNAL EMITTED FROM
TCM USING SUBARU SELECT MONITOR.
1) Move the select lever to “N” range with
throttle fully closed (vehicle speed 0 km/h or 0
MPH).
2) Read the data of transfer duty solenoid
using Subaru Select Monitor.
 Transfer duty solenoid is indicated in “%”.Is the value 5 — 10%? 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 9.
9 CHECK POOR CONTACT.Is there poor contact in transfer
duty solenoid circuit?Repair the poor
contact.Replace the TCM.
Transmission Con-
trol Module
(TCM).>
10 CHECK TRANSFER DUTY SOLENOID (IN
TRANSMISSION).
1) Lift-up the vehicle and place rigid rack.
NOTE:
Raise all wheels off ground.
2) Drain the automatic transmission fluid.
CAUTION:
Do not drain the automatic transmission flu-
id until it cools down.
3) Remove the extension case and disconnect
connector from transfer duty solenoid.
4) Measure the resistance between transfer
duty solenoid connector and transmission
ground.
Connector & terminal
(AT4) No. 1 — Transmission ground:Is the resistance 10 — 17 Ω? Go to step 11.Replace the trans-
fer duty solenoid.
11 CHECK HARNESS CONNECTOR BETWEEN
TRANSFER DUTY SOLENOID AND TRANS-
MISSION.
Measure the resistance of harness between
transfer duty solenoid and transmission con-
nector.
Connector & terminal
(T4) No. 6 — (AT4) No. 1:Is the resistance less than 1
Ω?Go to step 12.Repair the open
circuit in harness
between transfer
duty solenoid and
transmission con-
nector.
12 CHECK HARNESS CONNECTOR BETWEEN
TRANSFER DUTY SOLENOID AND TRANS-
MISSION.
Measure the resistance of harness between
transmission connector and transmission
ground.
Connector & terminal
(T4) No. 6 — 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
contact in transfer
duty solenoid and
transmission.Repair the short
circuit in harness
between transfer
duty solenoid and
transmission con-
nector. Step Check Yes No

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)-88
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure without Diagnostic Trouble Code (DTC)
B: CHECK BRAKE SWITCH
C: CHECK ABS SWITCH
D: CHECK CRUISE CONTROL SWITCH
Step Check Yes No
1 CHECK BRAKE SWITCH.When the brake pedal is
depressed, does LED light up?Go to step CHECK
ABS SWITCH.
4AT(H4SO)-88,
CHECK CRUISE
CONTROL
SWITCH, Diag-
nostic Procedure
without Diagnostic
Trouble Code
(DTC).>Check the brake
switch circuit.
EN(H4SO)-206,
DTC P0703
TORQUE CON-
VERTER/BRAKE
SWITCH “B” CIR-
CUIT, Diagnostic
Procedure with
Diagnostic Trou-
ble Code (DTC).>
Step Check Yes No
1 CHECK ABS SWITCH.Does the LED of ABS switch
light up?Check the ABS
switch circuit.
DTC 44 ABS-AT
CONTROL (NON
CONTROLLED),
Diagnostics Proce-
dure with Diagnos-
tic Trouble Code
(DTC).> ABS-142, DTC 44
ABS-AT CON-
TROL (CON-
TROLLED),
Diagnostics Proce-
dure with Diagnos-
tic Trouble Code
(DTC).>Go to step CHECK
CRUISE CON-
TROL SWITCH.
4AT(H4SO)-88,
CHECK CRUISE
CONTROL
SWITCH, Diag-
nostic Procedure
without Diagnostic
Trouble Code
(DTC).>
Step Check Yes No
1 CHECK CRUISE CONTROL SWITCH.When the cruise control is set,
does LED light up?Go to step CHECK
KICK-DOWN
SWITCH. 4AT(H4SO)-89,
CHECK KICK–
DOWN SWITCH,
Diagnostic Proce-
dure without Diag-
nostic Trouble
Code (DTC).>Check the cruise
control. CC(H4SO)-29,
Diagnostic Proce-
dure with Diagnos-
tic Trouble Code
(DTC).>

4AT(H4SO)-93
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure without Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK POWER SWITCH OPERATION.When the POWER switch is
turned to OFF, does LED light
up?Go to step 5.Go to step 2.
2 CHECK POWER SWITCH OPERATION.When the POWER switch is
turned to ON, does LED light
up?Go to step CHECK
INHIBITOR
SWITCH. 4AT(H4SO)-95,
CHECK INHIBI-
TOR SWITCH,
Diagnostic Proce-
dure without Diag-
nostic Trouble
Code (DTC).>Go to step 3.
3 CHECK POWER INDICATOR LIGHT.
1) Turn the ignition switch to OFF.
2) Remove the combination meter.
3) Remove the POWER indicator light bulb
from combination meter.Is the POWER indicator light
bulb OK?Go to step 4.Inspect the combi-
nation meter.
Combination
Meter Assembly.>
4 CHECK POWER SWITCH GROUND LINE.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from POWER
switch.
3) Measure the resistance of harness connec-
tor between POWER switch and chassis
ground.
Connector & terminal
LHD model
(R92) No. 4 — Chassis ground:
RHD model
(B133) No. 4 — Chassis ground:Is the resistance less than 1
Ω?Go to step 5.Repair the open
circuit in harness
between POWER
switch and chas-
sis ground.
5 CHECK POWER SWITCH.
1) Turn the POWER switch to ON.
2) Measure the resistance between terminals
of POWER switch.
Te r m i n a l s
No. 5 — No. 4:Is the resistance less than 1
Ω?Go to step 6.Repair the
POWER switch.
6 CHECK POWER SWITCH.
1) Turn the POWER switch to OFF.
2) Measure the resistance between terminals
of POWER switch.
Te r m i n a l s
No. 5 — No. 4:Is the resistance more than 1
MΩ?Go to step 7.Repair the
POWER switch.
7 CHECK HARNESS CONNECTOR BETWEEN
TCM AND POWER SWITCH.
Measure the resistance of harness connector
between TCM and POWER switch.
Connector & terminal
(B55) No. 23 — (B133) No. 3:Is the resistance less than 1
Ω?Go to step 8.Repair the open
circuit in harness
between TCM and
POWER switch
connector.
8 CHECK HARNESS CONNECTOR BETWEEN
TCM AND POWER SWITCH.
Measure the resistance of harness connector
between TCM and chassis ground.
Connector & terminal
(B55) No. 23 — Chassis ground:Is the resistance more than 1
MΩ?Go to step 9.Repair the short
circuit in harness
between TCM and
POWER switch
connector.

4AT(H4SO)-98
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure without Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK “P” RANGE SWITCH.When the “P” range is
selected, does LED light up?Go to step 2.Go to step 22.
2 CHECK INDICATOR LIGHT.Does the combination meter
“P” range indicator illuminate?Go to step 3.Go to step 26.
3 CHECK “P” RANGE SWITCH.When the “R” range is selected,
does “P” range LED light up?Go to step 28.Go to step 4.
4 CHECK “R” RANGE SWITCH.When the “R” range is
selected, does LED light up?Go to step 5.Go to step 29.
5 CHECK INDICATOR LIGHT.Does the combination meter
“R” range indicator illuminate?Go to step 6.Go to step 32.
6 CHECK “R” RANGE SWITCH.When the “N” range is selected,
does “R” range LED light up?Go to step 34.Go to step 7.
7 CHECK “N” RANGE SWITCH.When the “N” range is
selected, does LED light up?Go to step 8.Go to step 35.
8 CHECK INDICATOR LIGHT.Does the combination meter
“N” range indicator illuminate?Go to step 9.Go to step 38.
9 CHECK “N” RANGE SWITCH.When the “D” range is selected,
does “N” range LED light up?Go to step 40.Go to step 10.
10 CHECK “D” RANGE SWITCH.When the “D” range is
selected, does LED light up?Go to step 11.Go to step 41.
11 CHECK INDICATOR LIGHT.Does the combination meter
“D” range indicator illuminate?Go to step 12.Go to step 44.
12 CHECK “D” RANGE SWITCH.When the “3” range is selected,
does “D” range LED light up?Go to step 46.Go to step 13.
13 CHECK “3” RANGE SWITCH.When the “3” range is selected,
does LED light up?Go to step 14.Go to step 47.
14 CHECK INDICATOR LIGHT.Does the combination meter
“3” range indicator illuminate?Go to step 15.Go to step 50.
15 CHECK “3” RANGE SWITCH.When the “2” range is selected,
does “3” range LED light up?Go to step 52.Go to step 16.
16 CHECK “2” RANGE SWITCH.When the “2” range is selected,
does LED light up?Go to step 17.Go to step 53.
17 CHECK INDICATOR LIGHT.Does the combination meter
“2” range indicator illuminate?Go to step 18.Go to step 56.
18 CHECK “2” RANGE SWITCH.When the “1” range is selected,
does “2” range LED light up?Go to step 58.Go to step 19.
19 CHECK “1” RANGE SWITCH.When the “1” range is selected,
does LED light up?Go to step 20.Go to step 59.
20 CHECK INDICATOR LIGHT.Does the combination meter
“1” range indicator illuminate?Go to step 21.Go to step 62.
21 CHECK “1” RANGE SWITCH.When the “2” range is selected,
does “1” range LED light UP?Go to step 64.Go to step CHECK
HOLD SWITCH.
4AT(H4SO)-106,
CHECK HOLD
SWITCH, Diag-
nostic Procedure
without Diagnostic
Trouble Code
(DTC).>

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