2004 SUBARU FORESTER ignition

EN(H4DOTC 2.5)-134
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK HARNESS BETWEEN KNOCK SEN-
SOR AND ECM CONNECTOR.
Measure the resistance of harness between
ECM connector and chassis ground.
Connector & terminal
(B136) No. 25 — Chassis ground:Is the resistance less than 400
kΩ?Go to step 2.Go to step 3.
2 CHECK KNOCK SENSOR.
1) Disconnect the connector from knock sensor.
2) Measure the resistance between knock
sensor connector terminal and engine ground.
Te r m i n a l s
No. 2 — Engine ground:Is the resistance less than 400
kΩ?Replace the knock
sensor. FU(H4DOTC 2.5)-
29, Knock Sen-
sor.>Repair ground short
circuit in harness
between knock sen-
sor connector and
ECM connector.
N
OTE:
The harness be-
tween both con-
nectors are
shielded. Repair
short circuit in har-
ness covered with
shield.
3 CHECK INPUT SIGNAL FROM ECM.
1) Connect the connectors to ECM and knock
sensor.
2) Turn the ignition switch to ON.
3) Measure the voltage between ECM and
chassis ground.
Connector & terminal
(B136) No. 25 (+) — Chassis ground (
−):Is the voltage more than 2 V? Even if the mal-
function indicator
light illuminates,
the circuit has
returned to a nor-
mal condition at
this time. (How-
ever, the possibility
of poor contact still
remains.)
N
OTE:
In this case repair
the following:
 Poor contact in
knock sensor con-
nector
 Poor contact in
ECM connector.
 Poor contact in
coupling connectorRepair the poor
contact in ECM
connector.

EN(H4DOTC 2.5)-136
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK HARNESS BETWEEN CRANK-
SHAFT POSITION SENSOR AND ECM CON-
NECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from the crank-
shaft position sensor.
3) Measure the resistance of harness
between crankshaft position sensor connector
and engine ground.
Connector & terminal
(E10) No. 1 — Engine ground:Is the resistance more than
100 kΩ?Repair the harness
and connector.
N
OTE:
In this case repair
the following:
 Open circuit in
harness between
crankshaft posi-
tion sensor and
ECM connector
 Poor contact in
ECM connector.
 Poor contact in
coupling connectorGo to step 2.
2 CHECK HARNESS BETWEEN CRANK-
SHAFT POSITION SENSOR AND ECM CON-
NECTOR.
Measure the resistance of harness between
crankshaft position sensor connector and
engine ground.
Connector & terminal
(E10) No. 1 — Engine ground:Is the resistance more than 1
MΩ?Go to step 3.Repair ground short
circuit in harness
between crankshaft
position sensor and
ECM connector.
NOTE:
The harness be-
tween both con-
nectors are
shielded. Repair
ground short circuit
in harness togeth-
er with shield.
3 CHECK HARNESS BETWEEN CRANK-
SHAFT POSITION SENSOR AND ECM CON-
NECTOR.
Measure the resistance of harness between
crankshaft position sensor connector and
engine ground.
Connector & terminal
(E10) No. 2 — Engine ground:Is the resistance less than 5 Ω? Go to step 4.Repair the harness
and connector.
NOTE:
In this case repair
the following:
 Open circuit in
harness between
crankshaft posi-
tion sensor and
ECM connector
 Poor contact in
ECM connector.
 Poor contact in
coupling connector
4 CHECK CONDITION OF CRANKSHAFT PO-
SITION SENSOR.Is the crankshaft position sen-
sor installation bolt tightened
securely?Go to step 5.Tighten the crank-
shaft position sen-
sor installation bolt
securely.
5 CHECK CRANKSHAFT POSITION SENSOR.
1) Remove the crankshaft position sensor.
2) Measure the resistance between connector
terminals of crankshaft position sensor.
Te r m i n a l s
No. 1 — No. 2:Is the resistance 1 — 4 kΩ? Repair poor con-
tact in crankshaft
position sensor
connector.Replace the crank-
shaft position sen-
sor. FU(H4DOTC 2.5)-
27, Crankshaft
Position Sensor.>

EN(H4DOTC 2.5)-138
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK POWER SUPPLY OF CAMSHAFT
POSITION SENSOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from camshaft
position sensor.
3) Measure the voltage between camshaft
position sensor and engine ground.
Connector & terminal
(E36) No. 1 (+) — Engine ground (
−):Is the voltage more than 10 V? Repair the battery
short circuit
between main relay
connector and
camshaft position
sensor connector.Go to step 2.
2 CHECK POWER SUPPLY OF CAMSHAFT
POSITION SENSOR.
1) Turn the ignition switch to ON.
2) Measure the voltage between camshaft
position sensor and engine ground.
Connector & terminal
(E36) No. 1 (+) — Engine ground (
−):Is the voltage more than 10 V? Go to step 3.Repair open or bat-
tery short circuit
between main relay
connector and
camshaft position
sensor connector.
3 CHECK HARNESS BETWEEN CAMSHAFT
POSITION SENSOR AND ECM.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM.
3) Measure the resistance between camshaft
position sensor and ECM.
Connector & terminal
(E36) No. 2 — (B135) No. 9:
(E36) No. 3 — (B136) No. 35:Is the resistance less than 1
Ω?Go to step 4.Repair open circuit
between camshaft
position sensor
and ECM.
4 CHECK HARNESS BETWEEN CAMSHAFT
POSITION SENSOR AND ECM.
Measure the resistance between camshaft
position sensor and engine ground.
Connector & terminal
(E36) No. 2 — Engine ground:
(E36) No. 3 — Engine ground:Is the resistance more than 1
MΩ?Go to step 5.Repair ground short
circuit between
camshaft position
sensor and ECM.
5 CHECK CONDITION OF CAMSHAFT POSI-
TION SENSOR.Is the camshaft position sensor
installation bolt tightened
securely?Go to step 6.Tighten the cam-
shaft position sen-
sor installation bolt
securely.
6 CHECK CAMSHAFT POSITION SENSOR.
Check waveform of camshaft position sensor.
Module (ECM) I/O Signal.>Is there any abnormality in
waveform?Replace the cam-
shaft position sen-
sor. FU(H4DOTC 2.5)-
28, Camshaft
Position Sensor.>Go to step 7.
7 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 2.5)-
41, Engine Con-
trol Module
(ECM).>

EN(H4DOTC 2.5)-140
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK POWER SUPPLY OF CAMSHAFT
POSITION SENSOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from camshaft
position sensor.
3) Measure the voltage between camshaft
position sensor and engine ground.
Connector & terminal
(E35) No. 1 (+) — Engine ground (
−):Is the voltage more than 10 V? Repair the battery
short circuit
between main relay
connector and cam-
shaft position sen-
sor connector.Go to step 2.
2 CHECK POWER SUPPLY OF CAMSHAFT
POSITION SENSOR.
1) Turn the ignition switch to ON.
2) Measure the voltage between camshaft
position sensor and engine ground.
Connector & terminal
(E35) No. 1 (+) — Engine ground (
−):Is the voltage more than 10 V? Go to step 3.Repair open or
battery short cir-
cuit between main
relay connector
and camshaft
position sensor
connector.
3 CHECK HARNESS BETWEEN CAMSHAFT
POSITION SENSOR AND ECM.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM.
3) Measure the resistance between camshaft
position sensor and ECM.
Connector & terminal
(E35) No. 2 — (B135) No. 8:
(E35) No. 3 — (B136) No. 35:Is the resistance less than 1 Ω? Go to step 4.Repair open circuit
between camshaft
position sensor
and ECM.
4 CHECK HARNESS BETWEEN CAMSHAFT
POSITION SENSOR AND ECM.
Measure the resistance between camshaft
position sensor and engine ground.
Connector & terminal
(E35) No. 2 — Engine ground:
(E35) No. 3 — Engine ground:Is the resistance more than 1
MΩ?Go to step 5.Repair ground short
circuit between
camshaft position
sensor and ECM.
5 CHECK CONDITION OF CAMSHAFT POSI-
TION SENSOR.Is the camshaft position sensor
installation bolt tightened
securely?Go to step 6.Tighten the cam-
shaft position sen-
sor installation bolt
securely.
6 CHECK CAMSHAFT POSITION SENSOR.
Check waveform of camshaft position sensor.
Module (ECM) I/O Signal.>Is there any abnormality in
waveform?Replace the cam-
shaft position sen-
sor. FU(H4DOTC 2.5)-
28, Camshaft
Position Sensor.>Go to step 7.
7 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 2.5)-
41, Engine Con-
trol Module
(ECM).>

EN(H4DOTC 2.5)-142
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK OUTPUT SIGNAL FROM ECM.
1) Turn the ignition switch to ON.
2) Measure the voltage between ECM and
chassis ground.
Connector & terminal
(B134) No. 14 (+) — Chassis ground (
−):Is the voltage more than 10 V? Even if the mal-
function indicator
light illuminates,
the circuit has
returned to a nor-
mal condition at
this time.Go to step 2.
2 CHECK HARNESS BETWEEN PURGE CON-
TROL SOLENOID VALVE AND ECM CON-
NECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from purge con-
trol solenoid valve and ECM.
3) Measure the resistance of harness
between purge control solenoid valve connec-
tor and engine ground.
Connector & terminal
(E4) No. 2 — Engine ground:Is the resistance more than 1
MΩ?Go to step 3.Repair ground
short circuit in har-
ness between
ECM and purge
control solenoid
valve connector.
3 CHECK HARNESS BETWEEN PURGE CON-
TROL SOLENOID VALVE AND ECM CON-
NECTOR.
Measure the resistance of harness between
ECM and purge control solenoid valve of har-
ness connector.
Connector & terminal
(B134) No. 14 — (E4) No. 2:Is the resistance less than 1
Ω?Go to step 4.Repair open circuit
in harness between
ECM and purge
control solenoid
valve connector.
N
OTE:
In this case repair
the following:
 Open circuit in
harness between
ECM and purge
control solenoid
valve connector
 Poor contact in
coupling connector
4 CHECK PURGE CONTROL SOLENOID
VALVE.
1) Remove the purge control solenoid valve.
2) Measure the resistance between purge
control solenoid valve terminals.
Te r m i n a l s
No. 1 — No. 2:Is the resistance 10 — 100 Ω? Go to step 5.Replace the purge
control solenoid
valve. EC(H4DOTC)-7,
Purge Control
Solenoid Valve.>
5 CHECK POWER SUPPLY TO PURGE CON-
TROL SOLENOID VALVE.
1) Turn the ignition switch to ON.
2) Measure the voltage between purge control
solenoid valve and engine ground.
Connector & terminal
(E4) No. 1 (+) — Engine ground (
−):Is the voltage more than 10 V? Go to step 6.Repair open circuit
in harness
between main
relay and purge
control solenoid
valve connector.
6 CHECK POOR CONTACT.
Check poor contact in purge control solenoid
valve connector.Is there poor contact in purge
control solenoid valve connec-
tor?Repair poor con-
tact in purge con-
trol solenoid valve
connector.Contact the SUB-
ARU dealer.
N
OTE:
Inspection by DTM
is required, be-
cause probable
cause is deteriora-
tion of multiple
parts.

EN(H4DOTC 2.5)-144
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK OUTPUT SIGNAL FROM ECM.
1) Turn the ignition switch to OFF.
2) Connect the test mode connector at the lower
portion of instrument panel (on the driver’s side).
3) Turn the ignition switch to ON.
4) While operating the purge control solenoid
valve, measure voltage between ECM and
chassis ground.
N
OTE:
Purge control solenoid valve operation can be
executed using Subaru Select Monitor. For the
procedure, refer to “Compulsory Valve Opera-
tion Check Mode”. 43, Compulsory Valve Operation Check
Mode.>
Connector & terminal
(B134) No. 14 (+) — Chassis ground (
−):Is the voltage 0 — 13 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. In this
case, repair poor
contact in ECM
connector.
2 CHECK OUTPUT SIGNAL FROM ECM.
1) Turn the ignition switch to ON.
2) Measure the voltage between ECM and
chassis ground.
Connector & terminal
(B134) No. 14 (+) — Chassis ground (
−):Is the voltage more than 10 V? Go to step 4.Go to step 3.
3 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 2.5)-
41, Engine Con-
trol Module
(ECM).>
4 CHECK HARNESS BETWEEN PURGE CON-
TROL SOLENOID VALVE AND ECM CON-
NECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from purge con-
trol solenoid valve.
3) Turn the ignition switch to ON.
4) Measure the voltage between ECM and
chassis ground.
Connector & terminal
(B134) No. 14 (+) — Chassis ground (
−):Is the voltage more than 10 V? Repair battery
short circuit in har-
ness between
ECM and purge
control solenoid
valve connector.
After repair,
replace the ECM.
FU(H4DOTC 2.5)-
41, Engine Con-
trol Module
(ECM).>Go to step 5.
5 CHECK PURGE CONTROL SOLENOID
VALVE.
1) Turn the ignition switch to OFF.
2) Measure the resistance between purge
control solenoid valve terminals.
Te r m i n a l s
No. 1 — No. 2:Is the resistance less than 1
Ω?Replace the purge
control solenoid
valve and ECM.
EC(H4DOTC)-7,
Purge Control
Solenoid Valve.>
FU(H4DOTC 2.5)-
41, Engine Con-
trol Module
(ECM).>Go to step 6.
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 2.5)-
41, Engine Con-
trol Module
(ECM).>

EN(H4DOTC 2.5)-145
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
AH:DTC P0462 FUEL LEVEL SENSOR CIRCUIT LOW INPUT
DTC DETECTING CONDITION:
Two consecutive driving cycles with fault
CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode OPERATION, Clear Memory Mode.> and Inspection Mode Inspection Mode.>.
WIRING DIAGRAM:
EN-02367
B72
R59 R58B21
B136
i11
1
2345678910
R15 B136
ECM No.14
i10
B38
B21 E2
B98
R2 i3 B38
i3
E E E
FUEL
GAUGE
B:
i11 C: SBF-4 SBF-1
B721 4
B9 B10
C1
3
17
R15
R59R572 1
2
R583
53
16 20
12 1 3
4562123
4
56
78
9
1011 12
1314 15 16
C:
56
782 1
94 310
24 22 23 2511 12 13
1415
26 27
2816
17 18 19 20 21
33 34 29
32 30
31 35
2 20
16
BATTERY
IGNITION SWITCH
COMBINATION
METER
FUEL SUB
LEVEL SENSORFUEL
LEVEL SENSOR
3412
123456789101112131415161718192021222324252627282930
i10 B:
B38i3
3412
B98
219
32
1234
5610 11 12 13 14 15716
23 3019 20
22 26 27 28 29817
24 3118
25

EN(H4DOTC 2.5)-146
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK SPEEDOMETER AND TACHOME-
TER OPERATION IN COMBINATION
METER.Does the speedometer and
tachometer operate normally?Go to step 2.Repair or replace
the combination
meter. 3, Combination
Meter System.>
2 CHECK INPUT SIGNAL FROM ECM.
1) Turn the ignition switch to ON. (engine
OFF)
2) Measure the voltage between ECM con-
nector and chassis ground.
Connector & terminal
(B136) No. 20 (+) — Chassis ground (
−):Is the voltage less than 0.12
V?Go to step 4.Go to step 3.
3 CHECK INPUT SIGNAL FOR ECM WITH
SUBARU SELECT MONITOR.
Read the data of fuel level sensor signal using
Subaru Select Monitor.
N
OTE:
 Subaru Select Monitor
For detailed operation procedure, refer to
“READ CURRENT DATA SHOWN ON DIS-
PLAY FOR ENGINE”. 2.5)-27, Subaru Select Monitor.>Does the voltage change by
shaking the ECM harness and
connector?Repair the poor
contact in ECM
connector.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
may be the cause.
NOTE:
In this case repair
the following:
 Poor contact in
combination meter
connector
 Poor contact in
ECM connector.
 Poor contact in
coupling connector
4 CHECK INPUT VOLTAGE OF ECM.
1) Turn the ignition switch to OFF.
2) Separate fuel tank cord connector (R57)
and rear wiring harness connector (R15).
3) Turn the ignition switch to ON.
4) Measure the voltage of harness between
ECM connector and chassis ground.
Connector & terminal
(B136) No. 20 (+) — Chassis ground (
−):Is the voltage more than 0.12
V?Go to step 5.Go to step 6.
5 CHECK HARNESS BETWEEN ECM AND
COMBINATION METER.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from connector
(i10), (i11) and ECM connector.
3) Measure the resistance between ECM and
chassis ground.
Connector & terminal
(B136) No. 20 — Chassis ground:Is the resistance
more than 1 MΩ?Go to step 7.Repair the ground
short in harness
between ECM and
combination meter
connector.
6 CHECK HARNESS BETWEEN ECM AND
COMBINATION METER.
Measure the resistance between ECM and
combination meter connector.
Connector & terminal
(B136) No. 20 — (i11) No. 1:Is the resistance less than 10
Ω?Repair or replace
the combination
meter. 3, Combination
Meter System.>Repair open circuit
between ECM and
combination meter
connector.
NOTE:
In this case repair
the following:
Poor contact in
coupling connector