Subaru Legacy 2003 Service Manual page 884

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Step
1 CHECK CONDITION OF CAMSHAFT POSI-
TION SENSOR INSTALLATION.
Are the camshaft position sensor installing
bolts tightened securely?
2 CHECK CAMSHAFT POSITION SENSOR.
1) Remove camshaft position sensor.
2) Measure resistance between connector ter-
minals of camshaft position sensor.
Terminals
No. 1 — No. 2:
Is the measured value within the specified
value?
3 CHECK HARNESS BETWEEN ECM AND
CAMSHAFT POSITION SENSOR CONNEC-
TOR.
1) Connect connector to camshaft position
sensor.
2) Disconnect connector from ECM.
3) Measure resistance of harness between
camshaft position sensor connector and
ECM.
Connector & terminal
(B135) No. 8 — (B135) No. 1 (With
immobilizer)
(B135) No. 8 — (B135) No. 2 (Without
immobilizer)
Is the measured value within the specified
value?
4 CHECK HARNESS BETWEEN ECM AND
CAMSHAFT POSITION SENSOR CONNEC-
TOR.
Measure resistance of harness between ECM
connector and chassis ground.
Connector & terminal
(B135) No. 8 — Chassis ground:
Is the measured value less than the specified
value?
5 CHECK INPUT SIGNAL FOR ECM.
1) Turn ignition switch to OFF.
2) Disconnect connector from ECM.
3) Set the positive (+) probe and ground lead
of oscilloscope at ECM connector termi-
nals.
4) Measure voltage indicated on oscilloscope
while cranking the engine.
Connector & terminal
(B135) No. 1 (+) — (B135) No. 8 ( − − − − ):
(With immobilizer)
(B135) No. 2 (+) — (B135) No. 8 ( − − − − ):
(Without immobilizer)
Does the measured value exceed the spec-
ified value?
6 CHECK POOR CONTACT.
Check poor contact in ECM connector.
Is there poor contact in ECM connector?
Value
Bolts are securely tightened.
1 — 4 kΩ
1 — 5 kΩ
5 Ω
400 mV
There is poor contact.
EN(H4SOw/oOBD)-65
ENGINE (DIAGNOSTICS)
Yes
Go to step 2. Tighten camshaft
position sensor
installing bolts
securely.
Go to step 3. Replace camshaft
position sensor.
Go to step 4. Repair harness
and connector.
NOTE:
In this case, repair
the following:
• Open circuit in
harness between
camshaft position
sensor and ECM
connector
• Poor contact in
coupling connector
(B21)
Repair ground Go to step 5.
short circuit in har-
ness between
camshaft position
sensor and ECM
connector.
Go to step 6. Replace camshaft
position sensor.
Repair poor con- Go to step 7.
tact in ECM con-
nector.
No