Subaru Legacy (2005 year). Manual - part 437
EN(H6DO)(diag)-61
ENGINE (DIAGNOSTICS)
Diagnostics for Engine Starting Failure
2
CHECK IGNITION SYSTEM FOR SPARKS.
1) Connect the spark plug to ignition coil.
2) Release the fuel pressure.
3) Contact the spark plug’s thread portion on
engine.
4) While opening the throttle valve fully, start
the engine to check if spark occurs at each cyl-
inder.
Does spark occur at each cyl-
inder?
Check fuel pump
system. <Ref. to
EN(H6DO)(diag)-
62, FUEL PUMP
CIRCUIT, Diag-
nostics for Engine
Starting Failure.>
3
CHECK POWER SUPPLY CIRCUIT OF IGNI-
TION COIL.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ignition coil.
3) Turn the ignition switch to ON.
4) Measure the power supply voltage between
ignition coil 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 (
−
):
(E45) No. 3 (+) — Engine ground (
−
):
(E46) No. 3 (+) — Engine ground (
−
):
Is the voltage more than 10 V? Go to step 4.
Repair the har-
ness and connec-
tor.
NOTE:
In this case, repair
the following:
• Open circuit of
harness between
ignition coil and
ignition switch con-
nector
• Poor contact in
coupling connector
4
CHECK HARNESS OF IGNITION COIL
GROUND CIRCUIT.
1) Turn the ignition switch to OFF.
2) Measure the resistance between ignition
coil 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:
(E45) No. 2 — Engine ground:
(E46) No. 2 — Engine ground:
Is the resistance less than 5
Ω?
Repair the har-
ness and connec-
tor.
NOTE:
In this case, repair
the following:
• Open circuit of
harness between
ignition coil con-
nector and engine
ground terminal
5
CHECK HARNESS BETWEEN ECM AND IG-
NITION COIL CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM.
3) Disconnect the connector from ignition coil.
4) Measure the resistance of harness
between ECM and ignition coil connector.
Connector & terminal
(B135) No. 18 — (E31) No. 1:
(B135) No. 17 — (E32) No. 1:
(B135) No. 16 — (E33) No. 1:
(B135) No. 15 — (E34) No. 1:
(B135) No. 14 — (E45) No. 1:
(B135) No. 13 — (E46) No. 1:
Is the resistance less than 1
Ω?
Repair the har-
ness and connec-
tor.
NOTE:
In this case, repair
the following:
• Open circuit of
harness between
ECM and ignition
coil connector
• Poor contact in
coupling connector
6
CHECK HARNESS BETWEEN ECM AND IG-
NITION COIL CONNECTOR.
Measure the resistance of harness between
ECM and engine ground.
Connector & terminal:
(B135) No. 18 — Engine ground:
(B135) No. 17 — Engine ground:
(B135) No. 16 — Engine ground:
(B135) No. 15 — Engine ground:
(B135) No. 14 — Engine ground:
(B135) No. 13 — Engine ground:
Is the resistance more than 1
M
Ω?
Repair the ground
short circuit of har-
ness between
ECM and ignition
coil connector.
Step
Check
Yes
No