Subaru Forester 2004 Service Manual page 139

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTIC)
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) Measure the voltage between camshaft
position sensor and engine ground.
Connector & terminal
(E36) No. 1 (+) — Engine ground (
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 (
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:
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:
5 CHECK CONDITION OF CAMSHAFT POSI-
TION SENSOR.
6 CHECK CAMSHAFT POSITION SENSOR.
Check waveform of camshaft position sensor.
<Ref. to EN(H4DOTC 2.5)-17, Engine Control
Module (ECM) I/O Signal.>
7 CHECK POOR CONTACT.
Check poor contact in ECM connector.
Check
Is the voltage more than 10 V? Repair the battery
−
):
Is the voltage more than 10 V? Go to step 3.
−
):
Is the resistance less than 1
Ω?
Is the resistance more than 1
MΩ?
Is the camshaft position sensor
installation bolt tightened
securely?
Is there any abnormality in
waveform?
Is there poor contact in ECM
connector?
EN(H4DOTC 2.5)-138
Yes
Go to step 2.
short circuit
between main relay
connector and
camshaft position
sensor connector.
Repair open or bat-
tery short circuit
between main relay
connector and
camshaft position
sensor connector.
Go to step 4. Repair open circuit
between camshaft
position sensor
and ECM.
Go to step 5. Repair ground short
circuit between
camshaft position
sensor and ECM.
Go to step 6. Tighten the cam-
shaft position sen-
sor installation bolt
securely.
Replace the cam- Go to step 7.
shaft position sen-
sor. <Ref. to
FU(H4DOTC 2.5)-
28, Camshaft
Position Sensor.>
Repair the poor Replace the ECM.
contact in ECM <Ref. to
connector. FU(H4DOTC 2.5)-
41, Engine Con-
trol Module
(ECM).>
No