2004 SUBARU FORESTER check engine

EN(H4DOTC 2.5)-217
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. 18 — (E38) No. 1:
(B134) No. 28 — (E38) 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 oil flow con-
trol solenoid valve and engine ground.
Connector & terminal
(E38) No. 1 — Engine ground:
(E38) 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 2.5)-219
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. 18 — (E38) No. 1:
(B134) No. 28 — (E38) 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 oil flow
control solenoid valve and engine ground.
Connector & terminal
(E38) No. 1 — Engine ground:
(E38) 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 solenoid
valve. ME(H4DOTC)-68,
Camshaft.>

EN(H4DOTC 2.5)-221
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 oil flow con-
trol solenoid valve and engine ground.
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 2.5)-223
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 oil flow
control solenoid valve and engine ground.
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 2.5)-226
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK ELECTRONIC THROTTLE CON-
TROL RELAY.
1) Turn the ignition switch to OFF.
2) Remove the electronic throttle control relay.
3) Connect the battery to electronic throttle
control relay terminals No. 1 and No. 3.
4) Measure the resistance between electronic
throttle control relay terminals.
Te r m i n a l s
No. 2 — No. 4:Is the resistance less than 1
Ω?Go to step 2.Replace the elec-
tronic throttle con-
trol relay.
2 CHECK POWER SUPPLY OF ELECTRONIC
THROTTLE CONTROL RELAY.
Measure the voltage between electronic throt-
tle control relay connector and engine ground.
Connector & terminal
(B309) No. 1 (+) — Engine ground (
−):
(B309) No. 2 (+) — Engine ground (
−):Is the voltage more than 5 V? Go to step 3.Repair open or
ground short cir-
cuit of power sup-
ply circuit.
3 CHECK HARNESS BETWEEN ECM AND
ELECTRONIC THROTTLE CONTROL RE-
LAY.
1) Disconnect the connector from ECM.
2) Turn the ignition switch to ON.
3) Measure the voltage between electronic
throttle control relay connector and engine
ground.
Connector & terminal
(B309) No. 3 (+) — Engine ground (
−):Is the voltage less than 5 V? Go to step 4.Repair power sup-
ply short circuit in
harness between
ECM and electronic
throttle control.
4 CHECK HARNESS BETWEEN ECM AND
ELECTRONIC THROTTLE CONTROL RE-
LAY.
1) Turn the ignition switch to OFF.
2) Measure the resistance between electronic
throttle control relay connector and chassis
ground.
Connector & terminal
(B309) No. 3 — Engine ground:
(B309) No. 4 — Engine ground:Is the resistance more than 1
MΩ?Go to step 5.Repair ground
short circuit in har-
ness between
ECM and elec-
tronic throttle con-
trol relay.
5 CHECK HARNESS BETWEEN ECM AND
ELECTRONIC THROTTLE CONTROL RE-
LAY.
Measure the resistance between ECM connector
and electronic throttle control relay connector.
Connector & terminal
(B135) No. 35 — (B309) No. 3:
(B137) No. 6 — (B309) No. 4:Is the resistance less than 1
Ω?Go to step 6.Repair open circuit
in harness
between ECM and
electronic throttle
control relay.
6 CHECK SENSOR OUTPUT.
1) Connect all the connectors.
2) Turn the ignition switch to ON.
3) Measure the voltage between ECM con-
nector terminals.
Connector & terminal
(B136) No. 18 (+) — (B136) No. 35 (
−):
4) Check the voltage change by shaking the
harness and connector of ECM, engine har-
ness connector and electronic throttle control
connector.Is the voltage more than 0.4 V? Go to step 7.Go to step 9.

EN(H4DOTC 2.5)-227
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
7 CHECK SENSOR OUTPUT.
1) Connect all the connectors.
2) Turn the ignition switch to ON.
3) Measure the voltage between ECM con-
nector terminals.
Connector & terminal
(B136) No. 29 (+) — (B136) No. 35 (
−):
4) Check the voltage change by shaking the har-
ness and connector of ECM, engine harness con-
nector and electronic throttle control connector.Is the voltage more than 0.8 V? Go to step 8.Go to step 9.
8 CHECK POOR CONTACT.
Check the poor contact in connector between
ECM and electronic throttle control.Is there poor contact? Repair the poor
contact.Go to step 13.
9 CHECK HARNESS BETWEEN ECM AND
ELECTRONIC THROTTLE CONTROL.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM.
3) Disconnect the connectors from the elec-
tronic throttle control.
4) Measure the resistance between ECM con-
nector and electronic throttle control connector.
Connector & terminal
(B136) No. 16 — (E57) No. 5:Is the resistance less than 1
Ω?Go to step 10.Repair the open
circuit of harness
connector.
10 CHECK HARNESS BETWEEN ECM AND
ELECTRONIC THROTTLE CONTROL.
Measure the resistance between ECM connec-
tor and chassis ground.
Connector & terminal
(B136) No. 16 — Chassis ground:
(B136) No. 18 — Chassis ground:
(B136) No. 29 — Chassis ground:Is the resistance more than 1
MΩ?Go to step 11.Repair the ground
short circuit of har-
ness.
11 CHECK SENSOR POWER SUPPLY.
1) Connect the ECM connector.
2) Turn the ignition switch to ON.
3) Measure the voltage between electronic
throttle control connector and engine ground.
Connector & terminal
(E57) No. 5 (+) — Engine ground (
−):
4) Check the voltage change by shaking the
harness and connector of ECM and engine
harness connector while monitoring the value
with voltage meter.Is the voltage 4.5 — 5.5 V? Go to step 12.Repair the poor
contact in ECM
connector. Replace
the ECM if defec-
tive. FU(H4DOTC 2.5)-
41, Engine Con-
trol Module
(ECM).>
12 CHECK SHORT CIRCUIT IN ECM.
1) Turn the ignition switch to OFF.
2) Measure the resistance between electronic
throttle control connector and engine ground.
Connector & terminal
(E57) No. 4 — Engine ground:
(E57) No. 6 — Engine ground:Is the resistance more than 10
Ω?Go to step 13.Repair the poor
contact in ECM
connector.
Replace the ECM
if defective.
13 CHECK SENSOR OUTPUT.
1) Connect all the connectors.
2) Turn the ignition switch to ON.
3) Read the data of main throttle sensor signal
using Subaru Select Monitor.
4) Check the voltage change by shaking the
harness and connector of ECM, engine har-
ness connector and electronic throttle control
connector.Is the voltage 4.63 V? Go to step 14.Go to step 16. Step Check Yes No

EN(H4DOTC 2.5)-228
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
14 CHECK SENSOR OUTPUT.
1) Read the data of sub throttle sensor signal
using Subaru Select Monitor.
2) Check the voltage change by shaking the
harness and connector of ECM, engine har-
ness connector and electronic throttle control
connector.Is the voltage 4.73 V? Go to step 15.Go to step 16.
15 CHECK POOR CONTACT.
Check the poor contact in connector between
ECM and electronic throttle control.Is there poor contact? Repair the poor
contact.Go to step 21.
16 CHECK HARNESS BETWEEN ECM AND
ELECTRONIC THROTTLE CONTROL.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM.
3) Disconnect the connectors from the elec-
tronic throttle control.
4) Measure the resistance between ECM con-
nector and electronic throttle control connector.
Connector & terminal
(B136) No. 18 — (E57) No. 6:
(B136) No. 29 — (E57) No. 4:
(B136) No. 35 — (E57) No. 3:Is the resistance less than 1
Ω?Go to step 17.Repair the open
circuit of harness
connector.
17 CHECK HARNESS BETWEEN ECM AND
ELECTRONIC THROTTLE CONTROL.
1) Connect the ECM connector.
2) Measure the resistance between electronic
throttle control connector and engine ground.
Connector & terminal
(E57) No. 3 — Engine ground:Is the resistance less than 5
Ω?Go to step 18.Repair the poor
contact in ECM
connector.
Replace the ECM
if defective.
18 CHECK HARNESS BETWEEN ECM AND
ELECTRONIC THROTTLE CONTROL.
1) Turn the ignition switch to ON.
2) Measure the voltage between electronic
throttle control connector and engine ground.
Connector & terminal
(E57) No. 5 (+) — Engine ground (
−):
3) Check the voltage change by shaking the
harness and connector of ECM and engine
harness connector while monitoring the value
with voltage meter.Is the voltage more than 10 V? Go to step 19.Repair battery
short circuit in har-
ness between ECM
connector and elec-
tronic throttle con-
trol connector.
19 CHECK HARNESS BETWEEN ECM AND
ELECTRONIC THROTTLE CONTROL.
1) Measure the voltage between electronic
throttle control connector and engine ground.
Connector & terminal
(E57) No. 4 (+) — Engine ground (
−):
(E57) No. 6 (+) — Engine ground (
−):
2) Check the voltage change by shaking the
harness and connector of ECM and engine
harness connector while monitoring the value
with voltage meter.Is the voltage less than 10 V? Go to step 20.Repair short circuit
in harness
between ECM
connector and
electronic throttle
control connector. Step Check Yes No

EN(H4DOTC 2.5)-229
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
20 CHECK HARNESS BETWEEN ECM AND
ELECTRONIC THROTTLE CONTROL.
1) Turn the ignition switch to OFF.
2) Remove the ECM.
3) Measure the resistance between ECM con-
nectors.
Connector & terminal
(B136) No. 18 — (B136) No. 35:
(B136) No. 29 — (B136) No. 35:Is the resistance more than 1
MΩ?Go to step 21.Repair short circuit
to sensor power
supply.
21 CHECK SENSOR OUTPUT.
1) Turn the ignition switch to OFF.
2) Connect the connectors except of the elec-
tric control throttle relay.
3) Turn the ignition switch to ON.
4) Read the data of main throttle sensor signal
using Subaru Select Monitor.Is the voltage 0.81 — 0.87 V? Go to step 22.Repair poor contact
of electronic throt-
tle control connec-
tor. Replace the
electronic throttle
control if defective.
22 CHECK SENSOR OUTPUT.
Read the data of sub throttle sensor signal
using Subaru Select Monitor.Is the voltage 1.64 — 1.70 V? Go to step 23.Repair the poor
contact in ECM con-
nector. Replace the
electronic throttle
control if defective.
23 CHECK HARNESS BETWEEN ECM AND
ELECTRONIC THROTTLE CONTROL MO-
TOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM.
3) Disconnect the connectors from the elec-
tronic throttle control.
4) Measure the resistance between ECM con-
nector and electronic throttle control connector.
Connector & terminal
(B137) No. 4 — (E57) No. 1:
(B137) No. 5 — (E57) No. 2:Is the resistance less than 1
Ω?Go to step 24.Repair the open
circuit of harness
connector.
24 CHECK HARNESS BETWEEN ECM AND
ELECTRONIC THROTTLE CONTROL MO-
TOR.
1) Connect the connector to ECM.
2) Turn the ignition switch to ON.
3) Measure the voltage between electronic
throttle control connector and engine ground.
Connector & terminal
(E57) No. 1 (+) — Engine ground (
−):
(E57) No. 2 (+) — Engine ground (
−):Is the voltage less than 5 V? Go to step 25.Repair power sup-
ply short circuit in
harness between
ECM and electronic
throttle control.
25 CHECK HARNESS BETWEEN ECM AND
ELECTRONIC THROTTLE CONTROL MO-
TOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM.
3) Measure the resistance between electronic
throttle control connector and engine ground.
Connector & terminal
(E57) No. 1 — Engine ground:
(E57) No. 2 — Engine ground:Is the resistance more than 1
MΩ?Go to step 26.Repair the short
circuit of harness.
26 CHECK ELECTRONIC THROTTLE CON-
TROL MOTOR HARNESS.
Measure the resistance between electronic
throttle control connector terminals.
Connector & terminal
(E57) No. 2 — (E57) No. 1:Is the resistance more than 1
MΩ?Go to step 27.Repair the short
circuit of harness. Step Check Yes No