2004 SUBARU FORESTER automatic transmission

EN(H4SO)-8
ENGINE (DIAGNOSTIC)
General Description
 The OBD-II diagnostics procedure is different
from the usual diagnosis procedure. When trouble-
shooting the OBD-II models, connect Subaru Se-
lect Monitor or the OBD-II general scan tool to the
vehicle.
2. ENGINE AND EMISSION CONTROL SYS-
TEM
 MFI system is a system that supplies the opti-
mum air-fuel mixture to the engine for all the vari-
ous operating conditions through the use of the
latest electronic technology.
With this system fuel, which is pressurized at a con-
stant pressure, is injected into the intake air pas-
sage of the cylinder head. The injection quantity of
fuel is controlled by an intermittent injection system
where the electro-magnetic injection valve (fuel in-
jector) opens only for a short period of time, de-
pending on the quantity of air required for one cycle
of operation. In actual operation, the injection quan-
tity is determined by the duration of an electric sig-
nal applied to the fuel injector and this permits
simple, yet highly precise metering of the fuel.
 Further, all the operating conditions of the engine
are converted into electric signals, and this results
in additional features of the system, such as large
improved adaptability, easier addition of compen-
sating element, etc.The MFI system also has the following features:
 Reduced emission of harmful exhaust gases.
 Reduced in fuel consumption.
 Increased engine output.
 Superior acceleration and deceleration.
 Excellent engine start and warm-up perfor-
mance by the correction of engine coolant tem-
perature and intake air temperature.3. AUTOMATIC TRANSMISSION AND
ELECTRONIC-HYDRAULIC CONTROL SYS-
TEM
The electronic-hydraulic control system consists of
various sensors and switches, TCM and the hy-
draulic controller including solenoid valves. The
system controls the transmission body including
shift control, lock-up control, overrunning clutch
control, line pressure control and shift timing con-
trol. It also controls the AWD transfer clutch. In oth-
er words, the system detects various operating
conditions from various input signals and sends
output signals to shift solenoids 1, 2 and low clutch
timing solenoid and 2-4 brake timing solenoid, line
pressure duty solenoid, lock-up duty solenoid,
transfer duty solenoid and 2-4 brake duty solenoid
(a total of eight solenoids).
D: PREPARATION TOOL
ILLUSTRATION TOOL NUMBER DESCRIPTION REMARKS
24082AA230
(Newly adopted tool)CARTRIDGE Troubleshooting for electrical system.
22771AA030 SUBARU SELECT
MONITOR KITTroubleshooting for electrical system.
 English: 22771AA030 (Without printer)
 German: 22771AA070 (Without printer)
 French: 22771AA080 (Without printer)
 Spanish: 22771AA090 (Without printer)
ST24082AA230
ST22771AA030

EN(H4SO)-35
ENGINE (DIAGNOSTIC)
Subaru Select Monitor
8. READ CURRENT DATA FOR AT
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} 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 {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.
6) Using the scroll key, scroll the display screen up or down until the desired data is shown.
 A list of the support data is shown in the following table.
Description Display Unit of measure
Battery voltage Battery Voltage V
Rear vehicle speed sensor signal Rear Wheel Speed km/h or MPH
Front vehicle speed sensor signal Front Wheel Speed km/h or MPH
Engine speed signal Engine speed rpm
ATF temperature signal ATF Temp.°C or °F
Throttle position sensor Throttle Sensor Voltage V
Gear Position Gear position —
Line pressure control duty ratio Line pressure duty %
Lock up clutch control duty ratio L/U Duty %
Transfer clutch control duty ratio AWD duty %
Throttle position sensor power supply Throttle sensor power supply V
Turbine revolution signal Turbine Revolution Speed rpm
2-4 Brake timing pressure control duty ratio 2-4 B Pressure Duty %
Intake manifold pressure sensor voltage Mani. Relative Voltage V
FWD switch signal FWD SW ON or OFF
Kick down switch signal Kick Down Switch ON or OFF
Stop light switch signal Stop Light SW ON or OFF
Anti lock brake system signal ABS signal ON or OFF
Cruise control system signal Cruise Control Signal ON or OFF
Neutral/Parking range signal N/P range ON or OFF
Reverse range signal R Range ON or OFF
Drive range signal D Range ON or OFF
3rd range signal 3rd Range Signal ON or OFF
2nd range signal 2nd Range Signal ON or OFF
1st range signal 1st Range Signal ON or OFF
Shift control solenoid A Shift Solenoid #1 ON or OFF
Shift control solenoid B Shift Solenoid #2 ON or OFF
Torque control output signal #1 Torque control output signal 1 ON or OFF
Torque control output signal #2 Torque control output signal 2 ON or OFF
Torque control cut signal Torque Control Cut Sig ON or OFF
2-4 brake timing control solenoid valve 2-4B Timing Solenoid ON or OFF
Low clutch timing control solenoid valve L/C timing solenoid ON or OFF
Automatic transmission diagnosis light output signal Diagnosis Lamp ON or OFF

EN(H4SO)-209
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
BJ:DTC P0734 GEAR 4 INCORRECT RATIO
DTC DETECTING CONDITION:
Two consecutive driving cycles with fault
TROUBLE SYMPTOM:
 Shift point too high or too low.
 Engine brake not effected in 3rd range.
 Excessive shift shock.
 Excessive tight corner braking.
CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode ERATION, Clear Memory Mode.> and Inspection Mode tion Mode.>.
Step Check Yes No
1 CHECK ANY OTHER DTC ON DISPLAY.Is any other DTC displayed? Inspect the rele-
vant DTC using
“List of Diagnostic
Trouble Code
(DTC)”. EN(H4SO)-72, List
of Diagnostic Trou-
ble Code (DTC).>Go to step 2.
2 CHECK THROTTLE POSITION SENSOR
CIRCUIT.
Check the throttle position sensor circuit. to 4AT(H4SO)-41, DTC 31 THROTTLE POSI-
TION SENSOR, Diagnostic Procedure with
Diagnostic Trouble Code (DTC).>Is there any trouble in throttle
position sensor circuit?Repair or replace
the throttle posi-
tion sensor circuit.Go to step 3.
3 CHECK FRONT VEHICLE SPEED SENSOR
CIRCUIT.
Check front vehicle speed sensor circuit. to 4AT(H4SO)-45, DTC 33 FRONT VEHICLE
SPEED SENSOR, Diagnostic Procedure with
Diagnostic Trouble Code (DTC).>Is there any trouble in front
vehicle speed sensor circuit?Repair or replace
the front vehicle
speed sensor cir-
cuit.Go to step 4.
4 CHECK TORQUE CONVERTER TURBINE
SPEED SENSOR CIRCUIT.
Check torque converter turbine speed sensor
circuit. TORQUE CONVERTER TURBINE SPEED
SENSOR, Diagnostic Procedure with Diagnos-
tic Trouble Code (DTC).>Is there any trouble in torque
converter turbine speed sensor
circuit?Repair or replace
the torque con-
ver ter turbine
speed sensor cir-
cuit.Go to step 5.
5 CHECK POOR CONTACT.
Check poor contact in TCM connector.Is there poor contact in TCM
connector?Repair poor con-
tact in TCM con-
nector.Go to step 6.
6 CHECK MECHANICAL TROUBLE.
Check mechanical trouble in automatic trans-
mission.Is there any mechanical trou-
ble in automatic transmission?Repair or replace
the automatic
transmission.
INSPECTION,
Road Test.>Replace the TCM.
Transmission Con-
trol Module
(TCM).>

EN(H4SO)-211
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
8 CHECK ATF TEMPERATURE SENSOR CIR-
CUIT.
Check ATF temperature sensor circuit. 4AT(H4SO)-38, DTC 27 ATF TEMPERA-
TURE SENSOR, Diagnostic Procedure with
Diagnostic Trouble Code (DTC).>Is there any trouble in ATF tem-
perature sensor circuit?Repair or replace
the ATF tempera-
ture sensor circuit.Go to step 9.
9 CHECK POOR CONTACT.
Check poor contact in TCM connector.Is there poor contact in TCM
connector?Repair poor con-
tact in TCM con-
nector.Go to step 10.
10 CHECK MECHANICAL TROUBLE.
Check mechanical trouble in automatic trans-
mission.Is there any mechanical trou-
ble in automatic transmission?Repair or replace
the automatic
transmission.
INSPECTION,
Road Test.>Replace the TCM.
Transmission Con-
trol Module
(TCM).> Step Check Yes No

EN(H4SO)-223
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK HARNESS BETWEEN ECM AND
TCM CONNECTOR.
1) Turn the ignition switch to ON.
2) Measure the voltage between ECM and
chassis ground.
Connector & terminal
(B134) No. 10 (+) — Chassis ground (
−):Is the voltage less than 1 V? Go to step 2.Even if the mal-
function indicator
light illuminates,
the circuit has
returned to a nor-
mal condition at
this time.
N
OTE:
In this case repair
the following:
 Poor contact in
ECM connector.
 Poor contact in
TCM connector
2 CHECK HARNESS BETWEEN ECM AND
TCM CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM and
TCM.
3) Measure the resistance of harness
between ECM and chassis ground.
Connector & terminal
(B134) No. 10 — Chassis ground:Is the resistance more than 1
MΩ?Go to step 3.Repair ground
short circuit in har-
ness between
ECM and TCM
connector.
3 CHECK OUTPUT SIGNAL FROM ECM.
1) Connect the connector to ECM.
2) Turn the ignition switch to ON.
3) Measure the voltage between ECM and
chassis ground.
Connector & terminal
(B134) No. 10 (+) — Chassis ground (
−):Is the voltage more than 5 V? Go to step 4.Repair the poor
contact in ECM
connector.
4 CHECK DTC FOR AUTOMATIC TRANSMIS-
SION.
Read DTC for automatic transmission. 4AT(H4SO)-20, Read Diagnostic Trouble Code
(DTC).>Does the DTC appear for auto-
matic transmission?Check the DTC for
automatic trans-
mission. 4AT(H4SO)-36,
Diagnostic Proce-
dure with Diagnos-
tic Trouble Code
(DTC).>Replace the TCM.
Transmission Con-
trol Module
(TCM).>

EN(H4SO)-256
ENGINE (DIAGNOSTIC)
General Diagnostic Table
*1: Check ignition coil & ignitor ASSY and spark plug.
*2: Indicate the symptom occurring only in cold temperatures.
*3: Ensure the secure installation.
*4: Check fuel injector, fuel pressure regulator and fuel filter.
*5: Inspect air leak in air intake system.
*6: Adjust the accelerator cable.
2. AUTOMATIC TRANSMISSION
NOTE:
Check general diagnostics table with non-conformity symptom for automatic transmission. 4AT(H4SO)-2, Basic Diagnostic Procedure.>
6. Surging1) Intake manifold pressure sensor
2) Intake air temperature sensor
3) Manifold absolute pressure sensor
4) Engine coolant temperature sensor (*2)
5) Crankshaft position sensor (*3)
6) Camshaft position sensor (*3)
7) Fuel injection parts (*4)
8) Throttle position sensor
9) Fuel pump and fuel pump relay
7. Spark knock1) Intake manifold pressure sensor
2) Intake air temperature sensor
3) Manifold absolute pressure sensor
4) Engine coolant temperature sensor
5) Knock sensor
6) Fuel injection parts (*4)
7) Fuel pump and fuel pump relay
8. After burning in exhaust system1) Intake manifold pressure sensor
2) Intake air temperature sensor
3) Manifold absolute pressure sensor
4) Engine coolant temperature sensor (*2)
5) Fuel injection parts (*4)
6) Fuel pump and fuel pump relay Symptom Problem parts

ME(H4DOTC)-30
MECHANICAL
General Description
2. GENERAL TOOL
E: PROCEDURE
It is possible to conduct the following service proce-
dures with engine on the vehicle, however, the pro-
cedures described in this section are based on the
condition that the engine is removed from the vehi-
cle.
V-belt
 Timing Belt
 Camshaft
 Cylinder Head
498277200 STOPPER SET Used for installing automatic transmission
assembly to engine.
24082AA230
(Newly adopted tool)CARTRIDGE Troubleshooting for electrical systems.
22771AA030 SUBARU SELECT
MONITOR KITTroubleshooting for electrical systems.
 English: 22771AA030 (Without printer)
 German: 22771AA070 (Without printer)
 French: 22771AA080 (Without printer)
 Spanish: 22771AA090 (Without printer)
TOOL NAME REMARKS
Compression gauge Used for measuring compression.ILLUSTRATION TOOL NUMBER DESCRIPTION REMARKS
ST-498277200
ST24082AA230
ST22771AA030

EN(H4DOTC)-3
ENGINE (DIAGNOSTIC)
Basic Diagnostics Procedure
2. AUTOMATIC TRANSMISSION
When the DTC about automatic transmission is
shown on display, carry out the following basic
check.After that, carry out the replacement or re-
pair work.
1) ATF level check Transmission Fluid.>
2) Differential gear oil level check Differential Gear Oil.>
3) ATF leak check Transmission Fluid.>
4) Differential gear oil leak check Differential Gear Oil.>
5) Stall Test
6) Line Pressure Test sure Test.>
7) Transfer Clutch Pressure Test Transfer Clutch Pressure Test.>
8) Time Lag Test
9) Road Test
10) Shift characteristics Clutch Pressure Test.>