2004 SUBARU FORESTER check engine

EN(H4DOTC)-292
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK HARNESS BETWEEN ECM AND OIL
FLOW CONTROL SOLENOID VALVE.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM and oil
flow control solenoid valve.
3) Measure the resistance between ECM and
oil flow control solenoid valve.
Connector & terminal
(B134) No. 19 — (E37) No. 1:
(B134) No. 29 — (E37) No. 2:Is the resistance less than 1
Ω?Go to step 2.Repair open circuit
in harness
between ECM and
oil flow control
solenoid valve
connector.
N
OTE:
In this case, repair
the following:
 Open circuit in
harness between
ECM and oil flow
control solenoid
valve connector
 Poor contact in
coupling connector
2 CHECK HARNESS BETWEEN ECM AND OIL
FLOW CONTROL SOLENOID VALVE.
Measure the resistance between ECM and oil
flow control solenoid valve.
Connector & terminal
(E37) No. 1 — Engine ground:
(E37) No. 2 — Engine ground:Is the resistance more than 1
MΩ?Go to step 3.Repair short circuit
between ECM and
oil flow control
solenoid valve
connector.
3 CHECK OIL FLOW CONTROL SOLENOID
VALVE.
1) Remove the oil flow control solenoid valve
connector.
2) Measure the resistance between oil flow
control solenoid valve terminals.
Te r m i n a l s
No. 1 — No. 2:Is the resistance 6 — 12 Ω? Repair poor con-
tact in ECM and oil
flow control sole-
noid valve.Replace the oil
flow control sole-
noid valve. to ME(H4DOTC)-
68, Camshaft.>

EN(H4DOTC)-294
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK HARNESS BETWEEN ECM AND OIL
FLOW CONTROL SOLENOID VALVE.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM and oil
flow control solenoid valve.
3) Measure the resistance between ECM and
oil flow control solenoid valve.
Connector & terminal
(B134) No. 19 — (E37) No. 1:
(B134) No. 29 — (E37) No. 2:Is the resistance less than 1
Ω?Go to step 2.Repair open circuit
in harness
between ECM and
oil flow control
solenoid valve
connector.
N
OTE:
In this case, repair
the following:
 Open circuit in
harness between
ECM and oil flow
control solenoid
valve connector
 Poor contact in
coupling connector
2 CHECK HARNESS BETWEEN ECM AND OIL
FLOW CONTROL SOLENOID VALVE.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM and oil
flow control solenoid valve.
3) Measure the resistance between ECM and
oil flow control solenoid valve.
Connector & terminal
(E37) No. 1 — Engine ground:
(E37) No. 2 — Engine ground:Is the resistance more than 1
MΩ?Go to step 3.Repair short circuit
between ECM and
oil flow control
solenoid valve
connector.
3 CHECK OIL FLOW CONTROL SOLENOID
VALVE.
1) Remove the oil flow control solenoid valve
connector.
2) Measure the resistance between oil flow
control solenoid valve terminals.
Te r m i n a l s
No. 1 — No. 2:Is the resistance 6 — 12 Ω? Repair poor con-
tact in ECM and oil
flow control sole-
noid valve.Replace the oil
flow control sole-
noid valve. to ME(H4DOTC)-
68, Camshaft.>

EN(H4DOTC)-296
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 accelerator cable. 6. Surging1) Manifold absolute pressure sensor
2) Mass air flow and intake air temperature sensor
3) Engine coolant temperature sensor (*2)
4) Crankshaft position sensor (*3)
5) Camshaft position sensor (*3)
6) Fuel injection parts (*4)
7) Throttle position sensor
8) Fuel pump and fuel pump relay
7. Spark knock1) Manifold absolute pressure sensor
2) Mass air flow and intake air temperature sensor
3) Engine coolant temperature sensor
4) Knock sensor
5) Fuel injection parts (*4)
6) Fuel pump and fuel pump relay
8. After burning in exhaust system1) Manifold absolute pressure sensor
2) Mass air flow and intake air temperature sensor
3) Engine coolant temperature sensor (*2)
4) Fuel injection parts (*4)
5) Fuel pump and fuel pump relay Symptom Problem parts

ENGINE (DIAGNOSTIC)
EN(H4DOTC 2.5)
Page
1. Basic Diagnostics Procedure ......................................................................2
2. Check List for Interview ...............................................................................3
3. General Description ....................................................................................5
4. Electrical Component Location ...................................................................8
5. Engine Control Module (ECM) I/O Signal .................................................17
6. Engine Condition Data ..............................................................................22
7. Data Link Connector .................................................................................23
8. OBD-II General Scan Tool ........................................................................24
9. Subaru Select Monitor...............................................................................27
10. Read Diagnostic Trouble Code (DTC) ......................................................34
11. Inspection Mode ........................................................................................35
12. Drive Cycle ................................................................................................40
13. Clear Memory Mode..................................................................................42
14. Compulsory Valve Operation Check Mode ...............................................43
15. Malfunction Indicator Light ........................................................................45
16. Diagnostics for Engine Starting Failure .....................................................54
17. List of Diagnostic Trouble Code (DTC) .....................................................65
18. Diagnostic Procedure with Diagnostic Trouble Code (DTC) .....................70
19. General Diagnostic Table........................................................................258

EN(H4DOTC 2.5)-2
ENGINE (DIAGNOSTIC)
Basic Diagnostics Procedure
1. Basic Diagnostics Procedure
A: PROCEDURE
1. ENGINE
Step Check Yes No
1 CHECK ENGINE START FAILURE.
1) Ask the customer when and how the trou-
ble occurred using the interview check list.
Check List for Interview.>
2) Start the engine.Does the engine start? Go to step 2.Inspection using
“Diagnostics for
Engine Start Fail-
ure”. EN(H4DOTC 2.5)-
54, Diagnostics for
Engine Starting
Fai lu r e.>
2 CHECK ILLUMINATION OF MALFUNCTION
INDICATOR LIGHT.Does malfunction indicator
light illuminate?Go to step 3.Inspection using
“General Diagnos-
tic Table”. EN(H4DOTC 2.5)-
258, General Diag-
nostic Table.>
3 CHECK INDICATION OF DTC ON DISPLAY.
1) Turn the ignition switch to OFF.
2) Connect the Subaru Select Monitor or the
OBD-II general scan tool to data link connec-
tor.
3) Turn the ignition switch to ON and the Sub-
aru Select Monitor or OBD-II general scan tool
switch to ON.
4) Read the DTC on the Subaru Select Moni-
tor or OBD-II general scan tool.Does the Subaru Select Moni-
tor or OBD-II general scan tool
indicate DTC?Record the DTC.
Repair the trouble
cause. EN(H4DOTC 2.5)-
65, List of Diag-
nostic Trouble
Code (DTC).> Go
to step 4.Repair the related
parts.
N
OTE:
If DTC is not shown
on display although
the malfunction in-
dicator light illumi-
nates, perform the
diagnostics for mal-
function indicator
light circuit or com-
bination meter.
EN(H4DOTC 2.5)-
45, Malfunction In-
dicator Light.>
4 PERFORM THE DIAGNOSIS.
1) Perform clear memory mode. EN(H4DOTC 2.5)-42, Clear Memory Mode.>
2) Perform the “INSPECTION MODE”. to EN(H4DOTC 2.5)-35, Inspection Mode.>Does the Subaru Select Moni-
tor or OBD-II general scan tool
indicate DTC?Check on “Diag-
nostic Chart with
Diagnostic Trou-
ble Code (DTC)”.
EN(H4DOTC 2.5)-
70, Diagnostic
Procedure with
Diagnostic Trou-
ble Code (DTC).>Finish the diagno-
sis.

EN(H4DOTC 2.5)-3
ENGINE (DIAGNOSTIC)
Check List for Interview
2. Check List for Interview
A: INSPECTION
1. CHECK LIST No. 1
Check the following items when problem has occurred.
NOTE:
Use copies of this page for interviewing customers.
Customer’s name Engine No.
Date of sale Fuel brand
Date of repair
Odometer readingkm
V.I.N.miles
Weather❏ Fine
❏ Cloudy
❏ Rainy
❏ Snowy
❏ Va r i o u s / O t h e r s :
Ambient air temperature°C (°F)
❏ Hot
❏ War m
❏ Cool
❏ Cold
Place❏ Highway
❏ Suburbs
❏ Inner city
❏ Uphill
❏ Downhill
❏ Rough road
❏ Others:
Engine temperature❏ Cold
❏ War ming-up
❏ After warming-up
❏ Any temperature
❏ Others:
Engine speed rpm
Vehicle speed km/h (MPH)
Driving conditions❏ Not affected
❏ At starting
❏ While idling
❏ At racing
❏ While accelerating
❏ While cruising
❏ While decelerating
❏ While turning (RH/LH)
Headlight❏ ON / ❏ OFF Rear defogger❏ ON / ❏ OFF
Blower❏ ON / ❏ OFF Radio❏ ON / ❏ OFF
A/C compressor❏ ON / ❏ OFF CD/Cassette❏ ON / ❏ OFF
Radiator fan❏ ON / ❏ OFF Car phone❏ ON / ❏ OFF
Fr o nt wi pe r❏ ON / ❏ OFF CB❏ ON / ❏ OFF
Rear Wiper❏ ON / ❏ OFF

EN(H4DOTC 2.5)-4
ENGINE (DIAGNOSTIC)
Check List for Interview
2. CHECK LIST No. 2
Check the following items about the vehicle’s state when malfunction indicator light turns on.
NOTE:
Use copies of this page for interviewing customers.
a) Other warning lights or indicators turn on. ❏ Ye s / ❏ No
❏ Low fuel warning light
❏ Charge indicator light
❏ AT diagnostic indicator light
❏ ABS Warning Light
❏ Oil pressure indicator light
b) Fuel level
 Lack of gasoline: ❏ Yes / ❏ No
 Indicator position of fuel gauge:
 Experienced running out of fuel: ❏ Ye s / ❏ No
c) Intentional connecting or disconnecting of harness connectors or spark plug cords: ❏ Yes / ❏ No
 What:
d) Intentional connecting or disconnecting of hoses: ❏ Ye s / ❏ No
 What:
e) Installing of other parts except genuine parts: ❏ Ye s / ❏ No
 What:
 Where:
f) Occurrence of noise: ❏ Yes / ❏ No
From where:
 What kind:
g) Occurrence of smell: ❏ Yes / ❏ No
From where:
 What kind:
h) Intrusion of water into engine compartment or passenger compartment: ❏ Yes / ❏ No
i) Troubles occurred
❏ Engine does not start
❏ Engine stalls during idling
❏ Engine stalls while driving
❏ Engine speed decreases
❏ Engine speed does not decrease
❏ Rough idling
❏ Poor acceleration
❏ Back fire
❏ After fire
❏ Does not shift
❏ Excessive shift shock

EN(H4DOTC 2.5)-6
ENGINE (DIAGNOSTIC)
General Description
13) Diagnostics should be conducted by rotating
with simple, easy operations and proceeding to
complicated, difficult operations. The most impor-
tant thing in diagnostics is to understand the cus-
tomer’s complaint, and distinguish between the
three causes.
14) On the model with ABS, when performing driv-
ing test in jacked-up or lifted-up position, some-
times the warning light may be lit, but this is not a
malfunction of the system. The reason for this is the
speed difference between the front and rear
wheels. After diagnosis of engine control system,
perform the ABS memory clearance procedure of
self-diagnosis function.
B: INSPECTION
Before performing diagnostics, check the following
items which might affect engine problems:
1. BATTERY
1) Measure battery voltage and specific gravity of
electrolyte.
Standard voltage: 12 V
Specific gravity: Above 1.260
2) Check the condition of the main and other fuses,
and harnesses and connectors. Also check for
proper grounding.
2. ENGINE GROUND
Make sure the engine ground terminal is properly
connected to the engine.
C: NOTE
1. GENERAL DESCRIPTION
 On-board diagnosis (OBD) system detects and
indicates a fault in various inputs and outputs of the
complex electronic control. Malfunction indicator
light in the combination meter indicates occurrence
of a fault or trouble.
 Further, against such a failure or sensors as may
disable the drive, the fail-safe function is provided
to ensure the minimal driveability.
 The OBD system incorporated with the vehicles
within this engine family complies with Section
1968.1, California Code of Regulations (OBD-II
regulation). The OBD system monitors the compo-
nents and the system malfunction listed in Engine
Section which affects on emissions.
 When the system decides that a malfunction oc-
curs, malfunction indicator light illuminates. At the
same time of the malfunction indicator light illumi-
nation or blinking, the DTC and a freeze frame en-
gine conditions are stored into on-board computer.
 The OBD system stores freeze frame engine
condition data (engine load, engine coolant tem-
perature, fuel trim, engine speed and vehicle
speed, etc.) into on-board computer when it detects
a malfunction first.
 If the OBD system detects the various malfunc-
tions including the fault of fuel trim or misfire, the
OBD system first stores freeze frame engine condi-
tions about the fuel trim or misfire.
 When the malfunction does not occur again for
three consecutive driving cycles, malfunction indi-
cator light is turned off, but DTC remains at on-
board computer.
 The OBD-II system is capable of communication
with a general scan tool (OBD-II general scan tool)
formed by ISO 9141 CARB.
 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.
EN-01201