2004 SUBARU FORESTER check engine light

EN(H4DOTC)-44
ENGINE (DIAGNOSTIC)
Inspection Mode
5) Start the engine.
NOTE:
 Ensure the select lever is placed in the “P” range
before starting.(AT model)
 Depress the clutch pedal when starting the en-
gine.(MT model)
6) Using the selector lever or shift lever, turn the “P”
range switch and the “N” range switch to ON.
7) Depress the brake pedal to turn the brake switch
ON.(AT model)
8) Keep the engine speed in the 2,500 — 3,000
rpm range for 40 seconds.
9) Place the select lever or shift lever in the “D”
range (AT model) or “1st” gear (MT model) and
drive the vehicle at 5 to 10 km/h (3 to 6 MPH).
NOTE:
 On AWD vehicles, release the parking brake.
 The speed difference between front and rear
wheels may light either the ABS warning light, but
this indicates no malfunctions.When engine control
diagnosis is finished, perform the ABS memory
clearance procedure of self-diagnosis function.
10) Using the OBD-II general scan tool, check
DTC(s) and record the result(s).
NOTE:
 For detailed operation procedures, refer to the
OBD-II General Scan Tool Operation Manual.
 For details concerning DTCs, refer to the List of
Diagnostic Trouble Code (DTC).
ble Code (DTC).>

EN(H4DOTC)-50
ENGINE (DIAGNOSTIC)
Malfunction Indicator Light
16.Malfunction Indicator Light
A: PROCEDURE
1. Activation of malfunction indicator light. function Indicator Light.>
↓
2. Check that the malfunction indicator light does not come on. DOES NOT COME ON, Malfunction Indicator Light.>
↓
3. Check that the malfunction indicator light does not go off. DOES NOT GO OFF, Malfunction Indicator Light.>
↓
4. Malfunction indicator light does not blink at a cycle of 3 Hz. DOES NOT BLINK AT A CYCLE OF 3 HZ, Malfunction Indicator Light.>
↓
5. Malfunction indicator light remains blinking at a cycle of 3 Hz. REMAINS BLINKING AT A CYCLE OF 3 HZ, Malfunction Indicator Light.>

EN(H4DOTC)-53
ENGINE (DIAGNOSTIC)
Malfunction Indicator Light
Step Check Yes No
1 CHECK OUTPUT SIGNAL FROM ECM.
1) Turn the ignition switch to ON.
2) Measure the voltage between ECM con-
nector and chassis ground.
Connector & terminal
(B134) No. 17 (+) — Chassis ground (
−):Is the voltage less than 1 V? Go to step 4.Go to step 2.
2 CHECK POOR CONTACT.Does the malfunction indicator
light come on when shaking or
pulling the ECM connector and
harness?Repair the poor
contact in ECM
connector.Go to step 3.
3 CHECK ECM CONNECTOR.Is the ECM connector correctly
connected?Replace the ECM.
FU(H4DOTC)-50,
Engine Control
Module (ECM).>Repair the con-
nection of ECM
connector.
4 CHECK HARNESS BETWEEN COMBINA-
TION METER AND ECM CONNECTOR.
1) Turn the ignition switch to OFF.
2) Remove the combination meter. IDI-10, Combination Meter Assembly.>
3) Disconnect the connector from ECM and
combination meter.
4) Measure the resistance of harness
between ECM and combination meter connec-
tor.
Connector & terminal
(B134) No. 17 — (i12) No. 1:Is the resistance less than 1
Ω?Go to step 5.Repair the har-
ness and connec-
tor.
NOTE:
In this case repair
the following:
 Open circuit in
harness between
ECM and combi-
nation meter con-
nector
 Poor contact in
coupling connector
5 CHECK POOR CONTACT.
Check poor contact in combination meter con-
nector.Is there poor contact in combi-
nation meter connector?Repair poor con-
tact in combination
meter connector.Go to step 6.
6 CHECK HARNESS BETWEEN COMBINA-
TION METER AND IGNITION SWITCH CON-
NECTOR.
1) Turn the ignition switch to ON.
2) Measure the voltage between combination
meter connector and chassis ground.
Connector & terminal
(i10) No. 9 (+) — Chassis ground (
−):Is the voltage more than 10 V? Replace the board
of combination
meter. 10, Combination
Meter Assembly.>Check the follow-
ing and repair if
necessary.
N
OTE:
 Blown out of
fuse (No. 14)
 Open or short
circuit in harness
between fuse (No.
14) and battery
terminal
 Poor contact in
ignition switch con-
nector

EN(H4DOTC)-54
ENGINE (DIAGNOSTIC)
Malfunction Indicator Light
D: MALFUNCTION INDICATOR LIGHT DOES NOT GO OFF
DIAGNOSIS:
The malfunction indicator light circuit is shorted.
TROUBLE SYMPTOM:
Although malfunction indicator light comes on when the engine runs, DTC is not shown on the Subaru Select
Monitor or OBD-II general scan tool display.
WIRING DIAGRAM:
Step Check Yes No
1 CHECK HARNESS BETWEEN COMBINA-
TION METER AND ECM CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM.
3) Turn the ignition switch to ON.Does malfunction indicator
light illuminate?Repair short circuit
in harness
between combina-
tion meter and
ECM connector.Replace the ECM.
FU(H4DOTC)-50,
Engine Control
Module (ECM).>
EN-02309
BATTERYIGNITION
SWITCH
SBF-4SBF-1
B72
B72
B38
B134
ECM
i3
E
14
RHD
RHD
A17
B37
i12 A :
i10 B :
i12i10B134
i3
i2
LHD
LHD
5
COMBINATION
METER
3412
123 456
789 121310 11 14
*
16
B38
i3
B37No.14
*LHD : 17
RHD : 13
B9
A1
34
12 8910 11
12 13 14 15 16 17 18 19 20 21 22 23 24567219
32
1234 5610 11 12 13 14 15716
23 3019 20
22 26 27 28 29817
24 3118
25
12345678910111213141516171819202122232425262728293056 7
82 1
94 310
24 22 23 25 11 12 13 14 15
26 27
2816 17
18 19 20 21
33 34 29
32 30 31
A:

EN(H4DOTC)-56
ENGINE (DIAGNOSTIC)
Malfunction Indicator Light
Step Check Yes No
1 CHECK STATUS OF MALFUNCTION INDI-
CATOR LIGHT.
1) Turn the ignition switch to OFF.
2) Disconnect the test mode connectors
3) Turn the ignition switch to ON.(engine OFF)Does malfunction indicator
light illuminate?Go to step 2.Repair the mal-
function indictor
light circuit. to EN(H4DOTC)-
52, MALFUNC-
TION INDICA-
TOR LIGHT
DOES NOT
COME ON, Mal-
function Indicator
Light.>
2 CHECK HARNESS BETWEEN COMBINA-
TION METER AND ECM CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM.
3) Turn the ignition switch to ON.Does malfunction indicator
light illuminate?Repair ground
short circuit in har-
ness between
combination meter
and ECM connec-
tor.Go to step 3.
3 CHECK HARNESS BETWEEN TEST MODE
CONNECTOR AND CHASSIS GROUND.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM.
3) Measure the resistance of harness
between test mode connector and chassis
ground.
Connector & terminal
(B76) No. 1 — Chassis ground:Is the resistance less than 1
Ω?Go to step 4.Repair the har-
ness and connec-
tor.
N
OTE:
In this case repair
the following:
 Open circuit in
harness between
test mode connec-
tor and chassis
ground
4 CHECK POOR CONTACT.
Check poor contact in ECM connector.Is there poor contact in ECM
connector?Repair the poor
contact in ECM
connector.Go to step 5.
5 CHECK HARNESS BETWEEN ECM AND
TEST MODE CONNECTOR.
1) Connect the test mode connector.
2) Measure the resistance of harness
between ECM and chassis ground.
Connector & terminal
(B137) No. 15 — Chassis ground:Is the resistance less than 1
Ω?Go to step 6.Repair open circuit
in harness
between ECM and
test mode connec-
tor.
6 CHECK POOR CONTACT.
Check poor contact in ECM connector.Is there poor contact in ECM
connector?Repair the poor
contact in ECM
connector.Replace the ECM.
FU(H4DOTC)-50,
Engine Control
Module (ECM).>

EN(H4DOTC)-58
ENGINE (DIAGNOSTIC)
Malfunction Indicator Light
Step Check Yes No
1 CHECK TEST MODE CONNECTOR.
1) Disconnect the test mode connectors
2) Turn the ignition switch to ON.Does the malfunction indicator
light blink?Go to step 2.System is in good
order.
N
OTE:
Malfunction indica-
tor light blinks at a
cycle of 3 Hz when
test mode connec-
tor is connected.
2 CHECK HARNESS BETWEEN ECM CON-
NECTOR AND ENGINE GROUND TERMI-
NAL.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM.
3) Measure the resistance of harness
between ECM connector and chassis ground.
Connector & terminal
(B137) No. 15 — Chassis ground:Is the resistance less than 5
Ω?Repair the short
circuit in harness
between ECM and
test mode connec-
tor.Replace the ECM.
FU(H4DOTC)-50,
Engine Control
Module (ECM).>

ENGINE (DIAGNOSTIC)
EN(H4DOTC)
Page
1. Basic Diagnostics Procedure ......................................................................2
2. Check List for Interview ...............................................................................4
3. General Description ....................................................................................6
4. Electrical Component Location ...................................................................9
5. Engine Control Module (ECM) I/O Signal .................................................23
6. Engine Condition Data ..............................................................................27
7. Transmission Control Module (TCM) I/O Signal .......................................28
8. Data Link Connector .................................................................................29
9. OBD-II General Scan Tool ........................................................................30
10. Subaru Select Monitor...............................................................................33
11. Read Diagnostic Trouble Code (DTC) ......................................................39
12. Inspection Mode ........................................................................................40
13. Drive Cycle ................................................................................................45
14. Clear Memory Mode..................................................................................47
15. Compulsory Valve Operation Check Mode ...............................................48
16. Malfunction Indicator Light ........................................................................50
17. Diagnostics for Engine Starting Failure .....................................................59
18. List of Diagnostic Trouble Code (DTC) .....................................................74
19. Diagnostic Procedure with Diagnostic Trouble Code (DTC) .....................80
20. General Diagnostic Table........................................................................295

EN(H4DOTC)-100
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CONNECT SUBARU SELECT MONITOR OR
THE OBD-II GENERAL SCAN TOOL, AND
READ DATA.
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) Start the engine.
5) Connect the Subaru Select Monitor or
OBD-II general scan tool, and read the mass
air flow sensor voltage.
N
OTE:
 Subaru Select Monitor
For detailed operation procedure, refer to
“READ CURRENT DATA SHOWN ON DIS-
PLAY FOR ENGINE”. 33, Subaru Select Monitor.>
 OBD-II general scan tool
For detailed operation procedures, refer to the
OBD-II General Scan Tool Operation Manual.Is the voltage 0.2 — 4.7 V? Even if the mal-
function indicator
light illuminates,
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
harness or con-
nector in the mass
air flow sensor.
NOTE:
In this case repair
the following:
 Open or ground
short circuit in har-
ness between
mass air flow sen-
sor and ECM con-
nector
 Poor contact in
mass air flow sen-
sor or ECM con-
nectorGo to step 2.
2 CHECK INPUT SIGNAL FROM ECM.
Measure the voltage between ECM connector
and chassis ground while engine is idling.
Connector & terminal
(B136) No. 23 (+) — Chassis ground (
−):Is the voltage more than 0.2 V? Go to step 4.Go to step 3.
3 CHECK INPUT SIGNAL FOR ECM (WITH
SUBARU SELECT MONITOR).
Measure the voltage between ECM connector
and chassis ground while engine is idling.Does the voltage change by
shaking the harness and con-
nector of ECM while monitor-
ing the value with Subaru
Select Monitor?Repair the poor
contact in ECM
connector.Contact the SUB-
ARU dealer.
N
OTE:
Inspection by DTM
is required, because
probable cause is
deterioration of mul-
tiple parts.
4 CHECK POWER SUPPLY TO MASS AIR
FLOW SENSOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from mass air
flow sensor.
3) Turn the ignition switch to ON.
4) Measure voltage between mass air flow
sensor connector and chassis ground.
Connector & terminal
(B3) No. 1 (+) — Chassis ground (
−):Is the voltage more than 5 V? Go to step 5.Repair open circuit
between mass air
flow sensor and
main relay