Subaru Impreza 2003 Service Manual page 1347

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Step
1 CHECK HARNESS BETWEEN CRANK-
SHAFT POSITION SENSOR AND ECM CON-
NECTOR.
1)Turn the ignition switch to OFF.
2)Disconnect the connector from crankshaft
position sensor.
3)Measure the resistance of harness between
crankshaft position sensor connector and
engine ground.
Connector & terminal
(E10) No. 1 — Engine ground:
2 CHECK HARNESS BETWEEN CRANK-
SHAFT POSITION SENSOR AND ECM CON-
NECTOR.
Measure the resistance of harness between
crankshaft position sensor connector and
engine ground.
Connector & terminal
(E10) No. 1 — Engine ground:
3 CHECK HARNESS BETWEEN CRANK-
SHAFT POSITION SENSOR AND ECM CON-
NECTOR.
Measure the resistance of harness between
crankshaft position sensor connector and
engine ground.
Connector & terminal
(E10) No. 2 — Engine ground:
4 CHECK CONDITION OF CRANKSHAFT PO-
SITION SENSOR.
5 CHECK CRANKSHAFT POSITION SENSOR.
1)Remove the crankshaft position sensor.
2)Measure the resistance between connector
terminals of crankshaft position sensor.
Terminals
No. 1 — No. 2:
Check
Is the resistance more than
100 kΩ?
Is the resistance more than 1
MΩ?
Is the resistance less than 5
Ω?
Is the crankshaft position sen-
sor installation bolt tightened
securely?
Is the resistance 1 — 4 kΩ?
EN(H4DOTC)-171
ENGINE (DIAGNOSTICS)
Yes
Repair the har- Go to step 2.
ness and connec-
tor.
NOTE:
In this case, repair
the following:
• Open circuit in
harness between
crankshaft posi-
tion sensor and
ECM connector
• Poor contact in
ECM connector
• Poor contact in
coupling connector
Go to step 3. Repair the ground
short circuit in har-
ness between
crankshaft posi-
tion sensor and
ECM connector.
NOTE:
The harness be-
tween both con-
nectors
shielded.
ground short circuit
in harness togeth-
er with shield.
Go to step 4. Repair the har-
ness and connec-
tor.
NOTE:
In this case, repair
the following:
• Open circuit in
harness between
crankshaft posi-
tion sensor and
ECM connector
• Poor contact in
ECM connector
• Poor contact in
coupling connector
Go to step 5. Tighten the crank-
shaft position sen-
sor installation bolt
securely.
Repair the poor Replace the crank-
contact in crank- shaft position sen-
shaft position sen- sor. <Ref. to
sor connector. FU(H4DOTC)-29,
Crankshaft Posi-
tion Sensor.>
No
are
Repair