Subaru 2009 IMPREZA Service Manual page 1411

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
Step
1 CHECK POWER SUPPLY OF CAMSHAFT
POSITION SENSOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from camshaft
position sensor.
3) Turn the ignition switch to ON.
4) Measure the voltage between camshaft
position sensor connector and engine ground.
Connector & terminal
(E35) No. 1 (+) — Engine ground (–):
2 CHECK HARNESS BETWEEN ECM AND
CAMSHAFT POSITION SENSOR CONNEC-
TOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from ECM.
3) Measure the resistance between ECM and
camshaft position sensor connector.
Connector & terminal
(B134) No. 21 — (E35) No. 2:
(B134) No. 22 — (E35) No. 3:
3 CHECK HARNESS BETWEEN ECM AND
CAMSHAFT POSITION SENSOR CONNEC-
TOR.
Measure the resistance between camshaft
position sensor connector and engine ground.
Connector & terminal
(E35) No. 2 — Engine ground:
4 CHECK HARNESS BETWEEN ECM AND
CAMSHAFT POSITION SENSOR CONNEC-
TOR.
Measure the voltage between camshaft posi-
tion sensor connector and engine ground.
Connector & terminal
(E35) No. 2 (+) — Engine ground (–):
5 CHECK CONDITION OF CAMSHAFT POSI-
TION SENSOR.
6 CHECK CAMSHAFT POSITION SENSOR.
Check the waveform of the camshaft position
sensor. <Ref. to EN(H4DOTC)(diag)-17,
Engine Control Module (ECM) I/O Signal.>
Check
Is the voltage 10 V or more?
Is the resistance less than 1 ? Go to step 3.
Is the resistance 1 M or
more?
Is the voltage 5 V or more?
Is the camshaft position sensor
installation bolt tightened
securely?
Is there any abnormality in
waveform?
EN(H4DOTC)(diag)-190
Yes No
Go to step 2. Repair the harness
and connector.
NOTE:
In this case, repair
the following item:
• Open circuit or
short
ground in harness
between main re-
lay connector and
camshaft position
sensor connector
• Poor contact of
coupling connector
Repair the harness
and connector.
NOTE:
In this case, repair
the following item:
• Open circuit in
harness between
ECM
and camshaft posi-
tion sensor con-
nector
• Poor contact of
coupling connector
Go to step 4. Repair short cir-
cuit to ground in
harness between
ECM and camshaft
position sensor
connector.
Repair the short Go to step 5.
circuit to power in
the harness
between ECM and
camshaft position
sensor connector.
Go to step 6. Tighten the cam-
shaft position sen-
sor installation bolt
securely.
Replace the cam- Repair the follow-
shaft position sen- ing item.
sor. <Ref. to • Poor contact of
FU(H4DOTC)-34, ECM connector
Camshaft Position • Poor contact of
Sensor.> camshaft position
sensor connector
• Poor contact of
coupling connector
circuit to
connector