Subaru Legacy 2004 Service Manual page 1423

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
Step
1 CHECK POWER SUPPLY CIRCUIT FOR IG-
NITION COIL & IGNITOR ASSY.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ignition coil
& ignitor ASSY.
3) Turn the ignition switch to ON.
4) Measure the power supply voltage between
ignition coil & ignitor ASSY 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 (
2 CHECK HARNESS OF ECM AND IGNITION
COIL & IGNITOR ASSY GROUND CIRCUIT.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from ECM.
3) Measure the resistance between ignition
coil & ignitor ASSY 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:
3 CHECK HARNESS BETWEEN ECM AND IG-
NITION COIL & IGNITOR ASSY CONNEC-
TOR.
1) Disconnect the connector from ignition coil
& ignitor ASSY.
2) Measure the resistance of harness
between ECM and ignition coil & ignitor ASSY
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:
4 CHECK HARNESS BETWEEN ECM AND IG-
NITION COIL & IGNITOR ASSY CONNEC-
TOR.
Measure the resistance of harness between
ignition coil & ignitor ASSY connector and
engine ground.
Connector & terminal:
(E31) No. 1 — Engine ground:
(E32) No. 1 — Engine ground:
(E32) No. 1 — Engine ground:
(E34) No. 1 — Engine ground:
Check
Is the voltage more than 10 V? Go to step 2.
"
):
"
):
"
):
"
):
Is the resistance less than 5
'?
Is the resistance less than 1
'?
Is the resistance more than 1
M'?
EN(H4DOTC)(diag)-134
Yes
Repair the har-
ness and connec-
tor.
NOTE:
In this case, repair
the following:
• Open circuit in
harness between
ignition coil & igni-
tor ASSY and igni-
tion switch
connector
• Poor contact in
coupling connector
Go to step 3. Repair the har-
ness and connec-
tor.
NOTE:
In this case, repair
the following:
• Open circuit in
harness between
ignition coil & igni-
tor ASSY connec-
tor and engine
grounding terminal
• Poor contact in
coupling connector
Go to step 4. Repair the har-
ness and connec-
torrepair the
harness and con-
nector.
NOTE:
In this case, repair
the following:
• Open circuit in
harness between
ECM and ignition
coil & ignitor ASSY
connector
• Poor contact in
coupling connector
Repair the poor Repair the har-
contact in terminal. ness and connec-
torrepair the
harness and con-
nector.
No