2004 SUBARU FORESTER light

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

4AT(H4SO)-101
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure without Diagnostic Trouble Code (DTC)
36 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 “N” range.
5) Measure the voltage between TCM and
chassis ground.
Connector & terminal
(B55) No. 14 (+) — Chassis ground (–):Is the voltage less than 1 V? Go to step 37.Go to step 65.
37 CHECK INPUT SIGNAL FOR TCM.
1) Position the select lever to any other than
“N” range.
2) Measure the voltage between TCM and
chassis ground.
Connector & terminal
(B55) No. 14 (+) — Chassis ground (–):Is the voltage more than 8 V? Go to step 65.Replace the TCM.
Transmission Con-
trol Module
(TCM).>
38 CHECK “N” RANGE INDICATOR LIGHT
BULB.
1) Turn the ignition switch to OFF.
2) Remove the combination meter.
3) Remove the “N” range indicator light bulb
from combination meter.Is the “N” range indicator light
bulb OK?Go to step 39.Replace the “N”
range indicator
light bulb. IDI-10, Combina-
tion Meter Assem-
bly.>
39 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. 14 — (i10) No. 3: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.
40 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. 14 — Chassis ground:Is the resistance more than 1
MΩ?Go to step 41.Repair the ground
short circuit in “N”
range circuit.
41 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. 4 — (T7) No. 3:Is the resistance less than 1
Ω?Go to step 42.Repair the open cir-
cuit in harness
between TCM and
inhibitor switch con-
nector, and poor
contact in coupling
connector.
42 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 “D” range.
5) Measure the voltage between TCM and
chassis ground.
Connector & terminal
(B55) No. 4 (+) — Chassis ground (–):Is the voltage less than 1 V? Go to step 43.Go to step 65. Step Check Yes No

4AT(H4SO)-102
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure without Diagnostic Trouble Code (DTC)
43 CHECK INPUT SIGNAL FOR TCM.
1) Position select lever to any other than “D”
range.
2) Measure the voltage between TCM and
chassis ground.
Connector & terminal
(B55) No. 4 (+) — Chassis ground (–):Is the voltage more than 8 V? Go to step 65.Replace the TCM.
Transmission Con-
trol Module
(TCM).>
44 CHECK “D” RANGE INDICATOR LIGHT
BULB.
1) Turn the ignition switch to OFF.
2) Remove the combination meter.
3) Remove the “D” range indicator light bulb
from combination meter.Is the “D” range indicator light
bulb OK?Go to step 45.Replace the “D”
range indicator
light bulb. IDI-10, Combina-
tion Meter Assem-
bly.>
45 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. 4 — (i10) No. 11: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
TCM connector.
46 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. 4 — Chassis ground:Is the resistance more than 1
MΩ?Go to step 47.Repair the ground
short circuit in “D”
range circuit.
47 CHECK HARNESS CONNECTOR BETWEEN
TCM AND INHIBITOR SWITCH.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from TCM and
inhibitor switch.
3) Measure the resistance of harness
between TCM and inhibitor switch connector.
Connector & terminal
(B55) No. 5 — (T7) No. 11:Is the resistance less than 1
Ω?Go to step 48.Repair the open cir-
cuit in harness
between TCM and
inhibitor switch con-
nector, and poor
contact in coupling
connector.
48 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 “3” range.
5) Measure the voltage between TCM and
chassis ground.
Connector & terminal
(B55) No. 5 (+) — Chassis ground (–):Is the voltage less than 1 V? Go to step 49.Go to step 65.
49 CHECK INPUT SIGNAL FOR TCM.
1) Position the select lever to any other than
“3” range.
2) Measure the voltage between TCM and
chassis ground.
Connector & terminal
(B55) No. 5 (+) — Chassis ground (–):Is the voltage more than 8 V? Go to step 65.Replace the TCM.
Transmission Con-
trol Module
(TCM).> Step Check Yes No

4AT(H4SO)-103
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure without Diagnostic Trouble Code (DTC)
50 CHECK “3” RANGE INDICATOR LIGHT
BULB.
1) Turn the ignition switch to OFF.
2) Remove the combination meter.
3) Remove the “3” range indicator light bulb
from combination meter.Is the “3” range indicator light
bulb OK?Go to step 51.Replace the “3”
range indicator
light bulb. IDI-10, Combina-
tion Meter Assem-
bly.>
51 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. 5 — (i10) No. 5:Is the resistance more 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.
52 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. 5 — Chassis ground:Is the resistance more than 1
MΩ?Go to step 53.Repair the ground
short circuit in “3”
range circuit.
53 CHECK HARNESS CONNECTOR BETWEEN
TCM AND INHIBITOR SWITCH.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from TCM and
inhibitor switch.
3) Measure the resistance of harness
between TCM and inhibitor switch connector.
Connector & terminal
(B55) No. 6 — (T7) No. 4:Is the resistance less than 1
Ω?Go to step 54.Repair the open cir-
cuit in harness
between TCM and
inhibitor switch con-
nector, and poor
contact in coupling
connector.
54 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 “2” range.
5) Measure the voltage between TCM and
chassis ground.
Connector & terminal
(B55) No. 6 (+) — Chassis ground (–):Is the voltage less than 1 V? Go to step 55.Go to step 65.
55 CHECK INPUT SIGNAL FOR TCM.
1) Position the select lever to any other than
“2” range.
2) Measure the voltage between TCM and
chassis ground.
Connector & terminal
(B55) No. 6 (+) — Chassis ground (–):Is the voltage more than 8 V? Go to step 65.Replace the TCM.
Transmission Con-
trol Module
(TCM).>
56 CHECK “2” RANGE INDICATOR LIGHT
BULB.
1) Turn the ignition switch to OFF.
2) Remove the combination meter.
3) Remove the “2” range indicator light bulb
from combination meter.Is the “2” range indicator light
bulb OK?Go to step 57.Replace the “2”
range indicator light
bulb. 10, Combination
Meter Assembly.> Step Check Yes No

4AT(H4SO)-104
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure without Diagnostic Trouble Code (DTC)
57 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. 6 — (i10) No. 6:Is the resistance less than 1
Ω?Go to step 65.Repair the open
circuit in harness
between TCM and
combination
meter, and poor
contact in TCM
connector.
58 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. 6 — Chassis ground:Is the resistance more than 1
MΩ?Go to step 59.Repair the ground
short circuit in “2”
range circuit.
59 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. 7 — (T7) No. 6:Is the resistance less than 1
Ω?Go to step 60.Repair the open cir-
cuit in harness
between TCM and
inhibitor switch con-
nector, and poor
contact in coupling
connector.
60 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 “1” range.
5) Measure the voltage between TCM and
chassis ground.
Connector & terminal
(B55) No. 7 (+) — Chassis ground (–):Is the voltage less than 1 V? Go to step 61.Go to step 65.
61 CHECK INPUT SIGNAL FOR TCM.
1) Position the select lever to any other than
“1” range.
2) Measure the voltage between TCM and
chassis ground.
Connector & terminal
(B55) No. 7 (+) — Chassis ground (–):Is the voltage more than 8 V? Go to step 65.Replace the TCM.
Transmission Con-
trol Module
(TCM).>
62 CHECK “1” RANGE INDICATOR LIGHT
BULB.
1) Turn the ignition switch to OFF.
2) Remove the combination meter.
3) Remove the “1” range indicator light bulb
from combination meter.Is the “1” range indicator light
bulb OK?Go to step 63.Replace the “1”
range indicator light
bulb. 10, Combination
Meter Assembly.>
63 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. 7 — (i10) No. 7:Is the resistance less than 1Ω? Go to step 65.Repair the open cir-
cuit in harness
between TCM and
combination meter,
poor contact in
TCM connector. Step Check Yes No

4AT(H4SO)-108
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure without Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK HOLD SWITCH OPERATION.When the HOLD switch is
turned to OFF, does LED light
up?Go to step 5.Go to step 2.
2 CHECK HOLD SWITCH OPERATION.When the HOLD switch is turned
to ON, does LED light up?Refer to “Symptom
Related Diagnos-
tic”. 4AT(H4SO)-110,
Symptom Related
Diagnostic.>Go to step 3.
3 CHECK HOLD 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. 19 — Chassis ground:Does the HOLD indicator light
illuminate?Go to step 4.Inspect the combi-
nation meter.
Combination
Meter Assembly.>
4 CHECK HOLD SWITCH GROUND LINE.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from HOLD
switch.
3) Measure the resistance of harness connec-
tor between HOLD 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 HOLD
switch and chas-
sis ground.
5 CHECK HOLD SWITCH.
1) Turn the HOLD switch to ON.
2) Measure the resistance between terminals
of HOLD switch.
Te r m i n a l s
No. 4 — No. 3:Is the resistance less than 1
Ω?Go to step 6.Replace the HOLD
switch.
6 CHECK HOLD SWITCH.
1) Turn the HOLD switch to OFF.
2) Measure the resistance between terminals
of HOLD switch.
Te r m i n a l s
No. 4 — No. 3:Is the resistance more than 1
MΩ?Go to step 7.Replace the HOLD
switch.
7 CHECK HARNESS CONNECTOR BETWEEN
TCM AND HOLD SWITCH.
1) Disconnect the connector TCM and combi-
nation meter.
2) Measure the resistance of harness connec-
tor between TCM and HOLD switch.
Connector & terminal
LHD model
(B55) No. 16 — (R92) No. 2:
RHD model
(B55) No. 16 — (B133) No. 2:Is the resistance less than 1
Ω?Go to step 8.Repair the open
circuit in harness
between TCM and
HOLD switch con-
nector and poor
contact in cou-
pling connector.
8 CHECK HARNESS CONNECTOR BETWEEN
TCM AND COMBINATION METER.
Measure the resistance of harness connector
TCM and combination meter.
Connector & terminal
(B55) No. 16 — (i10) No. 19: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 cou-
pling connector.

AUTOMATIC TRANSMISSION
(DIAGNOSTIC)
4AT(H4DOTC)
Page
1. Basic Diagnostic Procedure ........................................................................2
2. Check List for Interview ...............................................................................4
3. General Description ....................................................................................5
4. Electrical Components Location..................................................................8
5. Transmission Control Module (TCM) I/O Signal .......................................12
6. Subaru Select Monitor...............................................................................15
7. Read Diagnostic Trouble Code (DTC) ......................................................18
8. Inspection Mode ........................................................................................19
9. Clear Memory Mode..................................................................................20
10. Power Indicator Light Display....................................................................21
11. Diagnostic Procedure for Subaru Select Monitor Communication ............27
12. List of Diagnostic Trouble Code (DTC) .....................................................30
13. Diagnostic Procedure with Diagnostic Trouble Code (DTC) .....................33
14. Diagnostic Procedure without Diagnostic Trouble Code (DTC) ..............112
15. Symptom Related Diagnostic ..................................................................126

4AT(H4DOTC)-2
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Basic Diagnostic Procedure
1. Basic Diagnostic Procedure
A: PROCEDURE
Step Check Yes No
1 CHECK PRE-INSPECTION.
1) Ask the customer when and how trouble
occurred using interview checklist. 4AT(H4DOTC)-4, Check List for Interview.>
2) Before performing the diagnosis, inspect
following items which might influence the AT
problems.
 General inspection 5, INSPECTION, General Description.>
 Disconnection of harness connector
 Visually check the damage of harness
 Oil leak
 Stall speed test
 Line pressure test Pressure Test.>
 Transfer clutch pressure test 38, Transfer Clutch Pressure Test.>
 Time lag test Te s t . >
 Road test
 Inhibitor switch Switch.>Is the unit that might influence
AT problem normal?Go to step 2.Repair or replace
each item.
2 CHECK POWER INDICATOR LIGHT.
Turn the ignition switch to ON.Does the POWER indicator
light illuminate?Go to step 4.Go to step 3.
3 CHECK POWER INDICATOR LIGHT.
1) Turn the ignition switch to OFF.
2) Repair the POWER indicator light circuit or
power supply and ground line circuit.
Power Indicator Light Display.>
3) Turn the ignition switch to ON.Is the POWER indicator light
flashing?Go to step 4.Go to step 5.
4 READ OF DTC.
Calling up the DTC.
N
OTE:
If the communication function of Subaru Select
Monitor cannot be executed normally, check the
communication circuit. 27, COMMUNICATION FOR INITIALIZING IM-
POSSIBLE, Diagnostic Procedure for Subaru
Select Monitor Communication.>Is the DTC displayed? Go to step 6.
NOTE:
Record all DTC.Go to step 5.
5 PERFORM THE GENERAL DIAGNOSTICS.
1) Inspect using “Diagnostics Procedure with-
out DTC”. nostic Procedure without Diagnostic Trouble
Code (DTC).>
2) Inspect using “Symptom Related Diagnos-
tic”. Related Diagnostic.>
3) Perform the clear memory mode.
4) Perform the inspection mode. 4AT(H4DOTC)-19, Inspection Mode.>
5) Calling up the DTC.Is the DTC displayed? Go to step 6.Complete the
diagnosis.