Subaru 2002 IMPREZA Service Manual page 535

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Step
1 CHECK OUTPUT SIGNAL FROM ECM.
1)Turn the ignition switch to ON.
2)Measure the voltage between ECM and
chassis ground.
Connector & terminal
(B134) No. 24 (+) — Chassis ground ( − − − − ):
2 CHECK POWER SUPPLY TO AIR ASSIST IN-
JECTOR SOLENOID VALVE.
1)Turn the ignition switch to OFF.
2)Disconnect the connector from air assist
injector solenoid valve.
3)Turn the ignition switch to ON.
4)Measure the voltage between air assist
injector solenoid valve and engine ground.
Connector & terminal
(E42) No. 2 (+) — Engine ground ( − − − − ):
3 CHECK HARNESS BETWEEN ECM AND AIR
ASSIST INJECTOR SOLENOID VALVE CON-
NECTOR.
1)Turn the ignition switch to OFF.
2)Disconnect the connector from ECM.
3)Measure the resistance of harness between
ECM and air assist injector solenoid valve con-
nector.
Connector & terminal
(B134) No. 24 — (E42) No. 1:
4 CHECK HARNESS BETWEEN ECM AND AIR
ASSIST INJECTOR SOLENOID VALVE CON-
NECTOR.
Measure the resistance of harness between
ECM and chassis ground.
Connector & terminal
(B134) No. 24 — Chassis ground:
5 CHECK POOR CONTACT.
Check poor contact in ECM and air assist
injector solenoid valve connectors.
Check
Is the voltage more than 10 V? Repair the poor
Is the voltage more than 10 V? Go to step 3.
Is the resistance less than 1
Ω?
Is the resistance less than 10
Ω?
Is there poor contact in ECM
and air assist injector solenoid
valve connectors?
EN-103
ENGINE (DIAGNOSTICS)
Yes
Go to step 2.
contact in ECM
connector.
Repair the har-
ness and connec-
tor.
NOTE:
In this case, repair
the following:
• Open circuit in
harness between
air assist injector
solenoid valve and
main relay con-
nector
• Poor contact in
coupling connector
(B22)
Go to step 4. Repair the har-
ness and connec-
tor.
NOTE:
In this case, repair
the following:
• Open circuit in
harness between
ECM and air assist
injector solenoid
valve connector
• Poor contact in
coupling connector
(B22)
Repair the ground Go to step 5.
short circuit in har-
ness between
ECM and air assist
injector solenoid
valve connector.
Repair the poor Replace the air
contact in ECM assist injector
and air assist solenoid valve.
injector solenoid <Ref. to FU-40, Air
valve connectors. Assist Injector
Solenoid Valve.>
No