Subaru Impreza 2003 Service Manual page 1328

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
ENGINE (DIAGNOSTICS)
Step
5 CHECK HARNESS BETWEEN FUEL PUMP
CONTROL UNIT AND ECM CONNECTOR.
1)Turn the ignition switch to OFF.
2)Disconnect the connector from ECM.
3)Measure the resistance of harness between
fuel pump control unit and ECM connector.
Connector & terminal
(R122) No. 9 — (B134) No. 13:
(R122) No. 8 — (B137) No. 16:
6 CHECK HARNESS BETWEEN FUEL PUMP
CONTROL UNIT AND ECM CONNECTOR.
Measure the resistance of harness between
fuel pump control unit and chassis ground.
Connector & terminal
(R122) No. 9 — Chassis ground:
(R122) No. 8 — Chassis ground:
7 CHECK POOR CONTACT.
Check poor contact in ECM and fuel pump
control unit connector.
Check
Is the resistance less than 1
Ω?
Is the resistance more than 1
MΩ?
Is there poor contact in ECM
and fuel pump control unit con-
nector?
EN(H4DOTC)-152
Yes
Go to step 6. Repair the har-
ness and connec-
tor.
NOTE:
In this case, repair
the following:
• Open circuit
between fuel
pump control unit
and ECM
• Poor contact in
fuel pump control
unit and ECM con-
nector
Go to step 7. Repair the ground
short circuit
between fuel
pump control unit
and ECM.
Repair the poor Replace the fuel
contact in ECM pump control unit.
and fuel pump <Ref. to
control unit. FU(H4DOTC)-52,
Fuel Pump Control
Unit.>
No