EN(H4DOTC)-185
ENGINE (DIAGNOSTIC)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step Check Yes No
1 CHECK CURRENT DATA.
1) Start the engine.
2) Drive the vehicle at the speed of approx. 30
km/h (19 MPH), and then measure the ignition
timing advance angle using Subaru Select
Monitor or OBD-II general scan tool.
N
OTE:
Subaru Select Monitor
For detailed operation procedure, refer to
“READ CURRENT DATA SHOWN ON DIS-
PLAY FOR ENGINE”.
OBD-II general scan tool
For detailed operation procedures, refer to the
OBD-II General Scan Tool Operation Manual.Does the ignition timing
advance angle changed
smoothly according to engine
output?
Idling: −2 — +2°
Driving: −2 — +50°Repair the poor
contact connector.
N
OTE:
In this case, repair
the following:
Poor contact of
AVCS camshaft
position sensor
connector.
Poor contact in
ECM connector.Go to step 2.
2 CHECK HARNESS BETWEEN AVCS CAM-
SHAFT POSITION SENSOR CONNECTOR
AND ECM CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from AVCS cam-
shaft position sensor connector and ECM.
3) Measure the resistance of harness
between AVCS camshaft position sensor con-
nector and engine ground.
Connector & terminal
(B35) No. 1 — (B135) No. 20:
(B35) No. 2 — (B135) No. 28:Is the resistance less than 1
Ω?Go to step 3.Repair the har-
ness and connec-
tor.
N
OTE:
In this case, repair
the following:
Open circuit in
harness between
AVCS camshaft
position sensor
connector and
ECM connector
Poor contact in
ECM connector.
Poor contact in
coupling connector
3 CHECK HARNESS BETWEEN AVCS CAM-
SHAFT POSITION SENSOR CONNECTOR
AND ECM CONNECTOR.
Measure the resistance of harness between
AVCS camshaft position sensor connector and
engine ground.
Connector & terminal
(E35) No. 1 — Engine ground:
(E35) No. 2 — Engine ground:Is the resistance more than 1
MΩ?Go to step 4.Repair the ground
short circuit in har-
ness between
AVCS camshaft
position sensor
connector and
ECM connector.
NOTE:
The harness be-
tween both con-
nectors are
shielded.Repair
ground short circuit
in harness togeth-
er with shield.
4 CHECK CONDITION OF AVCS CAMSHAFT
POSITION SENSOR CONNECTOR.Is the AVCS camshaft position
sensor connector installation
bolt tightened securely?Go to step 5.Tighten the AVCS
camshaft position
sensor connector
installation bolt
securely.
5 CHECK AVCS CAMSHAFT POSITION SEN-
SOR CONNECTOR.
1) Remove the AVCS camshaft position sen-
sor connector.
2) Measure the resistance between the AVCS
camshaft position sensor connector terminals.
Te r m i n a l s
No. 1 — No. 2:Is the resistance 1 — 4 kΩ? Check for the oil
clogging on oil
pressure routing of
oil flow control
solenoid valve.Replace the AVCS
camshaft position
sensor connector.
AVCS Camshaft
Position Sensor.>
EN(H4DOTC)-288
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 ECM and oil
flow control solenoid valve.
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.
68, Camshaft.>
EN(H4DOTC)-290
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 ECM and
oil flow control solenoid valve.
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.
68, Camshaft.>
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.
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.
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
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)-60
ENGINE (DIAGNOSTIC)
Diagnostics for Engine Starting Failure
Step Check Yes No
1 CHECK SPARK PLUG CONDITION.
1) Remove the spark plug.
2) Check the spark plug condition.
plug.
2 CHECK IGNITION SYSTEM FOR SPARKS.
1) Connect the spark plug to ignition coil.
2) Release the fuel pressure.
PRESSURE, OPERATION, Fuel.>
3) Contact the spark plug’s thread portion on
engine.
4) While opening the throttle valve fully, crank
the engine to check that spark occurs at each
cylinder.Does spark occur at each cyl-
inder?Check fuel pump
system.
62, FUEL PUMP
CIRCUIT, Diag-
nostics for Engine
Starting Failure.>Go to step 3.
3 CHECK POWER SUPPLY CIRCUIT FOR IG-
NITION COIL & IGNITOR ASSY.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ignition coil
& ignitor ASSY.
3) Turn the ignition switch to ON.
4) Measure the power supply voltage between
ignition coil & ignitor ASSY connector and
engine ground.
Connector & terminal
(E31) No. 3 (+) — Engine ground (
−):
(E32) No. 3 (+) — Engine ground (
−):
(E33) No. 3 (+) — Engine ground (
−):
(E34) No. 3 (+) — Engine ground (
−):Is the voltage more than 10 V? Go to step 4.Repair the harness
and connector.
N
OTE:
In this case repair
the following:
Open circuit in
harness between
ignition coil & igni-
tor ASSY, and igni-
tion switch
connector
Poor contact in
coupling connector
4 CHECK HARNESS OF IGNITION COIL & IG-
NITOR ASSY GROUND CIRCUIT.
1) Turn the ignition switch to OFF.
2) Measure the resistance between ignition
coil & ignitor ASSY connector and engine
ground.
Connector & terminal
(E31) No. 2 — Engine ground:
(E32) No. 2 — Engine ground:
(E33) No. 2 — Engine ground:
(E34) No. 2 — Engine ground:Is the resistance less than 5
Ω?Go to step 5.Repair the harness
and connector.
N
OTE:
In this case repair
the following:
Open circuit in
harness between
ignition coil & igni-
tor ASSY connec-
tor and engine
ground terminal
5 CHECK HARNESS BETWEEN ECM AND IG-
NITION COIL & IGNITOR ASSY CONNEC-
TOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM.
3) Disconnect the connector from ignition coil
& ignitor ASSY.
4) Measure the resistance of harness
between ECM and ignition coil & ignitor ASSY
connector.
Connector & terminal
(B135) No. 15 — (E34) No. 1:
(B135) No. 16 — (E33) No. 1:
(B135) No. 17 — (E32) No. 1:
(B135) No. 18 — (E31) No. 1:Is the resistance less than 1
Ω?Go to step 6.Repair the harness
and connector.
N
OTE:
In this case repair
the following:
OPEN CIR-
CUIT IN HAR-
NESS BETWEEN
ECM AND IGNI-
TION COIL &
IGNITOR ASSY
CONNECTOR.
Poor contact in
coupling connector