2004 SUBARU FORESTER check engine

4AT(H4SO)-95
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure without Diagnostic Trouble Code (DTC)
G: CHECK INHIBITOR SWITCH
DETECTING CONDITION:
The input signal circuit of inhibitor switch is open or shorted.
TROUBLE SYMPTOM:
 Shift characteristics are erroneous.
 Engine brake is not effected when selector lever is in “3” range.
 Engine brake is not effected when selector lever is in “2” range.
 Engine brake is not effected when selector lever is in “1” range.

4AT(H4SO)-109
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Diagnostic Procedure without Diagnostic Trouble Code (DTC)
9 CHECK HARNESS CONNECTOR BETWEEN
TCM AND HOLD SWITCH.
Measure the resistance of harness connector
between TCM and chassis ground to make
sure that circuit does not short.
Connector & terminal
(B55) No. 16 — Chassis ground:Is the resistance more than 1
MΩ?Go to step 10.Repair the short
circuit in harness
between TCM and
HOLD switch con-
nector.
10 CHECK INPUT SIGNAL FOR TCM.
1) Connect the connectors to TCM and HOLD
switch.
2) Turn the ignition switch to ON (engine OFF).
3) Measure the signal voltage for TCM while
turning HOLD switch to OFF.
Connector & terminal
(B55) No. 16 (+) — Chassis ground (–):Is the voltage more than 8 V? Go to step 11.Replace the TCM.
Transmission Con-
trol Module
(TCM).>
11 CHECK INPUT SIGNAL FOR TCM.
Measure the signal voltage for TCM while turn-
ing HOLD switch to ON.
Connector & terminal
(B55) No. 16 (+) — Chassis ground (–):Is the voltage less than 1 V? Go to step 12.Replace the TCM.
Transmission Con-
trol Module
(TCM).>
12 CHECK POOR CONTACT.Is there poor contact in HOLD
switch circuit?Repair the poor
contact.A temporary poor
contact of the con-
nector or harness or
connector in HOLD
switch circuit. Step Check Yes No

4AT(H4DOTC)-6
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
General Description
5. OPERATION OF SELECT LEVER
Make sure there is no abnormal noise, dragging or
contact pattern in each select lever range.
WARNING:
Stop the engine while checking operation of se-
lect lever.
6. POWER SWITCH
Make sure that the POWER indicator light in com-
bination meter comes on, when turning the POW-
ER switch to ON.
7. HOLD SWITCH
Make sure that the HOLD indicator light in combina-
tion meter comes on, when turning the HOLD switch
to ON.
AT-00413
P
R
N
D
3
2
1
AT-00319
AT-00320

4AT(H4DOTC)-12
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Transmission Control Module (TCM) I/O Signal
5. Transmission Control Module (TCM) I/O Signal
A: ELECTRICAL SPECIFICATION
Check with ignition switch ON.
ItemConnector
No.Terminal No. Measuring conditions Voltage (V)Resistance
to chassis
ground (Ω)
Back-up power supply B5627
Ignition switch OFF 10 — 13 — 28
29
ACC power supply B56 16 Ignition switch ACC 10 — 13 —
Ignition power supplyB56 21
Ignition switch ON
(with engine OFF)10 — 13 —
B56 31
Inhibitor
switch“P” range
switchB55 5Select lever in “P” range Less than 1
—
Select lever in any other than
“P” range (except “N” range)More than 8
“N” range
switchB55 22Select lever in “N” range Less than 1
—
Select lever in any other
than “N” rangeMore than 8
“R” range
switchB55 14Select lever in “R” range Less than 1
—
Select lever in any other
than “R” rangeMore than 8
“D” range
switchB55 4Select lever in “D” range Less than 1
—
Select lever in any other
than “D” rangeMore than 8
“3” range
switchB54 16Select lever in “3” range Less than 1
—
Select lever in any other
than “3” rangeMore than 8
“2” range
switchB54 4Select lever in “2” range Less than 1
—
Select lever in any other
than “2” rangeMore than 8
“1” range
switchB54 10Select lever in “1” range Less than 1
—
Select lever in any other
than “1” rangeMore than 8
Brake switch B55 20Brake pedal depressed. More than 10.5
—
Brake pedal released. Less than 1
AT-01107
B54B55B56
1 2 7
8 9 5 6
3 4
10 11 12
19 20 21 13 14 15 16
17 18 22 23
241 2 7 8 95634
10 11 12 19 20 21
29 30 3113 14 15 16 17
27
28 18
22 23 24 25 26 1 2 3
8 9 104
11 12
13 14 15
165 6
7
17To
ToTo

4AT(H4DOTC)-13
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Transmission Control Module (TCM) I/O Signal
Accelerator pedal position
sensor (2.5 L model)
B55 19Throttle fully closed. More than 0.2
—
Throttle position sensor (2.0
L model)Throttle fully open. Less than 4.6
Accelerator pedal position
sensor power supply (2.5 L
model)B55 10 Ignition switch ON
(with engine OFF)Approx. 5 —
Throttle position sensor
power supply (2.0 L model)
ATF temperature sensor B55 21ATF temperature 20°C
(68°F)3.5 — 4.3 3.9 k — 4.7 k
ATF temperature 80°C
(176°F)1.5 — 1.9 500 — 600
Rear vehicle speed sensor B55 24Vehicle speed at least
20 km/h (12 MPH)More than 2 (AC range) —
Front vehicle speed sensor B55 6Vehicle stopped. 0
450 — 750
Vehicle speed at least
20 km/h (12 MPH)More than 1 (AC range)
Torque converter turbine
speed sensorB55 7Engine idling after warm-
up. (“D” range)0
450 — 750
Engine idling after warm-
up. (“N” range)More than 1 (AC range)
Vehicle speed output signal B56 1Vehicle speed at least
10 km/h (6 MPH)Less than 1←
→More than 4—
Engine speed signal B55 13Ignition switch ON
(with engine OFF)Less than 1
—
Ignition switch ON
(with engine ON)More than 5
(AC range)
Line pressure linear solenoid B56 20Ignition switch ON
(with engine OFF)
“R” range and throttle fully
closed after warm-up.5 — 7
4.0 — 8.0
Ignition switch ON
(with engine OFF)
“R” range and throttle fully
open after warm-up.3 — 5
Lock-up duty solenoid B56 5When lock up occurs. More than 10.5
2.0 — 4.5
When lock up is released. Less than 1
Transfer duty solenoid B56 4“P” or “N” range Less than 1
2.0 — 4.5
Throttle fully open and with
select lever in 1st gear.More than 10.5
2-4 brake duty solenoid B56 6“P” or “N” range More than 10.5
2.0 — 4.5
2nd or 4th gear Less than 1
High clutch duty solenoid B56 83rd or 4th gear Less than 1
2.0 — 4.5
“P” or “N” range More than 10.5
Low clutch duty solenoid B56 91st or 2nd gear Less than 1
2.0 — 4.5
“P” or “N” range More than 10.5
Low & reverse duty solenoid B56 7“P” or “N” range More than 10.5
2.0 — 4.5
“1” range More than 5
HOLD switch B54 2HOLD switch ON Less than 1
—
HOLD switch OFF More than 10.5 Check with ignition switch ON.
ItemConnector
No.Terminal No. Measuring conditions Voltage (V)Resistance
to chassis
ground (Ω)

4AT(H4DOTC)-15
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Subaru Select Monitor
6. Subaru Select Monitor
A: OPERATION
1. READ DIAGNOSTIC TROUBLE CODE
1) Prepare the Subaru Select Monitor kit.
2) Connect the diagnosis cable to Subaru Select
Monitor.
3) Insert the cartridge into Subaru Select Monitor.
General Description.>
4) Connect the Subaru Select Monitor to data link
connector.
(1) Data link connector located in the lower por-
tion of instrument panel (on driver’s side).
(2) Connect the diagnosis cable to data link con-
nector.
NOTE:
Do not connect scan tools except for Subaru Select
Monitor.5) Turn the ignition switch to ON (engine OFF) and
Subaru Select Monitor switch to ON.
6) On the «Main Menu» display screen, select the
{Each System Check} and press the [YES] key.
7) On the «System Selection Menu» display screen,
select the {Transmission Control System} and press
the [YES] key.
8) Press the [YES] key after the information of trans-
mission type is displayed.
9) On the «Transmission Diagnosis» display screen,
select the {Diagnostic Code(s) Display} and press
the [YES] key.
NOTE:
 For details concerning operation procedure, re-
fer to the “SUBARU SELECT MONITOR OPERA-
TION MANUAL”.
 For details concerning the DTC, refer to the DTC
LIST. Trouble Code (DTC).>
2. READ CURRENT DATA
1) On the «Main Menu» display screen, select the
{Each System Check} and press the [YES] key.
2) On the «System Selection Menu» display screen,
select the {Transmission Control System} and press
the [YES] key.
3) Press the [YES] key after the information of trans-
mission type is displayed.
4) On the «Transmission Diagnosis» display screen,
select the {Current Data Display & Save} and press
the [YES] key.
5) On the «Transmission Diagnosis» display screen,
select the {Data Display} and press the [YES] key.
AT-00338
AT-00339
AT-00422
(A) POWER switch
(A)
AT-00341

4AT(H4DOTC)-17
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Subaru Select Monitor
3. CLEAR MEMORY MODE
1) On the «Main Menu» display screen, select the
{2. Each System Check} and press the [YES] key.
2) On the «System Selection Menu» display screen,
select the {Transmission Control System} and press
the [YES] key.
3) Press the [YES] key after the information of
transmission type is displayed.
4) On the «Transmission Diagnosis» display screen,
select the {Clear Memory} and press the [YES] key.
5) When the “Done” is shown on display screen,
turn the Subaru Select Monitor and ignition switch
to OFF.
NOTE:
 For details concerning operation procedure, refer
to the SUBARU SELECT MONITOR OPERATION
MANUAL.
 When {Clear Memory 2} is selected and executed,
DTC and learned control memory is cleared. If Clear
Memory 2 is performed, execute the learning con-
trol. OF LEARNING CONTROL, OPERATION, Subaru
Select Monitor.>
4. FACILITATION OF LEARNING CON-
TROL
1) Shift the select lever to “P” range, and apply
parking brake.
2) Lift-up the vehicle.
3) Connect the Subaru Select Monitor to data link
connector, and then turn the ignition switch to ON.
4) Perform the {Clear Memory 2} using Subaru Select
Monitor. ORY MODE, OPERATION, Subaru Select Monitor.>
5) Using Subaru Select Monitor, check that the DTC
is not output. AGNOSTIC TROUBLE CODE, OPERATION, Sub-
aru Select Monitor.>
6) Warm-up the engine until the ATF temperature
which is displayed on the Subaru Select Monitor is
within 60 — 90°C (140 — 194°F). 4AT(H4DOTC)-15, READ CURRENT DATA, OP-
ERATION, Subaru Select Monitor.>
7) Shift the select lever to “R” range.
8) Turn all switches including headlight, air condi-
tioner, seat heater, rear defogger and etc. to OFF.
9) Turn the ignition switch to OFF.
10) Depress the brake pedal fully until the facilitation
of learning control is completed when the “Communi-
cation Failed!” is displayed on Subaru Select Monitor.
11) Turn the ignition switch to ON.
12) Check that the Subaru Select Monitor is re-
turned to normal operation.
13) Shift the select lever to “P” range, and then wait
for more than 3 seconds.14) Shift the select lever to “R” range, and then wait
for more than 3 seconds.
15) Shift the select lever to “N” range, and then wait
for more than 3 seconds.
16) Shift the select lever to “D” range, and then wait
for more than 3 seconds.
17) Shift the select lever to “N” range, and then wait
for more than 3 seconds.
18) Slightly depress the accelerator pedal fully.
19) Slightly release the accelerator pedal fully.
20) Start the engine, and idle it.
21) Shift the select lever to “D” range.
22) Start the facilitation of learning control. At this
time, the POWER indicator light in combination meter
blinks at 2 Hz. When the POWER indicator light does
not blink, turn the ignition switch to OFF and repeat
the procedures from step 4). When the POWER indi-
cator light which blinking at 2 Hz changes to blink at
0.5 Hz, facilitation of learning control is completed.
NOTE:
When blinking of POWER indicator light changes
from 2 Hz to 4 Hz during facilitation of learning con-
trol, repeat the procedure from step 4).
23) Shift the select lever to “N” range, and then turn
the ignition switch to OFF.
24) Shift the select lever to the “P” range, and then
complete the facilitation of learning control.

4AT(H4DOTC)-21
AUTOMATIC TRANSMISSION (DIAGNOSTIC)
Power Indicator Light Display
10.Power Indicator Light Display
A: OPERATION
When any item is malfunctioning, the display on POWER indicator light blinks from the time malfunction is
detected after starting the engine until ignition switch is turned to OFF. The malfunctioning part or unit can be
determined by a DTC during on-board diagnostics operation. Problems which occurred previously can also
be identified through the memory function. If the POWER indicator does not show a problem (although a
problem is occurring), the problem can be determined by checking the performance characteristics of each
sensor using select monitor. The indicator signal is as shown in the figure.
Perform the inspection when the POWER indicator light does not operate correctly. 22, INSPECTION, Power Indicator Light Display.>
(A) Ignition switch (engine OFF) (C) Faulty (engine ON) (D) Normal (POWER switch ON)
(B) Normal (engine ON)
(1) ON (4) 0.25 sec. (6) POWER switch ON
(2) OFF (5) Blink (7) POWER switch OFF
(3) 2 sec.
AT-01109
(4)
(3)
(1)
(2)
(1)
(2)
(1)
(2)
(1)
(2)(3)
(3)(5)
(6) (A)
(B)
(C)
(D)
(7)