Subaru IMPREZA 2004 Service Manual page 749

Step
2 CHECK POWER SUPPLY TO EACH FUEL
INJECTOR.
1)Turn the ignition switch to OFF.
2)Disconnect the connector from each cylinder
fuel injector.
3)Turn the ignition switch to ON.
4)Measure the power supply voltage between
the fuel injector terminal and engine ground.
Connector & terminal
#1 (E5) No. 2 (+) — Engine ground (–):
#2 (E16) No. 2 (+) — Engine ground ( − − − − ):
#3 (E6) No. 2 (+) — Engine ground (–):
#4 (E17) No. 2 (+) — Engine ground (–):
3 CHECK EACH FUEL INJECTOR.
1)Turn the ignition switch to OFF.
2)Measure the resistance between each fuel
injector terminals.
Terminals
No. 1 — No. 2:
4 CHECK HARNESS BETWEEN ECM AND
FUEL INJECTOR CONNECTOR.
1)Disconnect the connector from ECM.
2)Connect the connector to #1 fuel injector.
3)Measure the resistance of harness between
ECM and fuel injector connector.
Connector & terminal
(B134) No. 4 — (B136) No. 2:
5 CHECK HARNESS BETWEEN ECM AND
FUEL INJECTOR CONNECTOR.
Measure the resistance of harness between
ECM and fuel injector connector.
Connector & terminal
(B134) No. 4 — Chassis ground:
6 CHECK HARNESS BETWEEN ECM AND
FUEL INJECTOR CONNECTOR.
1)Connect the connector to #2 fuel injector.
2)Measure the resistance of harness between
ECM and fuel injector connector.
Connector & terminal
(B134) No. 13 — (B136) No. 2:
Diagnostics for Engine Starting Failure
Is the voltage more than 10 V? Go to step 3.
Is the resistance 5 — 20 Ω?
Is the resistance 5 — 20 Ω?
Is the resistance less than 1
Ω?
Is the resistance 5 — 20 Ω?
EN(H4SOw/oOBD)(diag)-53
Check
Go to step 4.
Go to step 5.
Repair the ground
short circuit in har-
ness between
ECM and fuel
injector connector.
Go to step 7.
ENGINE (DIAGNOSTICS)
Yes No
Repair the har-
ness and connec-
tor.
NOTE:
In this case, repair
the following:
• Open circuit in
harness between
main relay and fuel
injector connector
• Poor contact in
main relay connec-
tor
• Poor contact in
coupling connector
(B22)
• Poor contact in
fuel injector con-
nector
Replace the faulty
fuel injector.
Repair the har-
ness and connec-
tor.
NOTE:
In this case, repair
the following:
• Open circuit in
harness between
ECM and fuel
injector connector
• Poor contact in
coupling connector
(B22)
Go to step 6.
Repair the har-
ness and connec-
tor.
NOTE:
In this case, repair
the following:
• Open circuit in
harness between
ECM and fuel
injector connector
• Poor contact in
coupling connector
(B22)