Subaru Legacy 2004 Service Manual page 1402

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
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 in harness
between fuel pump control unit and ECM con-
nector.
Connector & terminal
(R122) No. 9 — (B137) No. 28:
(R122) No. 8 — (B135) No. 27:
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.
8 CHECK EXPERIENCE OF RUNNING OUT OF
FUEL.
Check
Is the resistance less than 1
'?
Is the resistance more than 1
M'?
Is there poor contact in ECM
and fuel pump control unit con-
nector?
Did the vehicle experience run-
ning out of fuel?
EN(H4DOTC)(diag)-113
ENGINE (DIAGNOSTICS)
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 Go to step 8.
contact in ECM
and fuel pump
control unit.
Finish the diagno- Replace the fuel
sis. pump control unit.
<Ref. to
NOTE:
FU(H4DOTC)-39,
DTC record may
Fuel Pump Control
be conducted as a
Unit.>
result of fuel pump
idling while running
out of fuel.
No