Subaru 2002 IMPREZA Service Manual page 1471

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Step
1 CHECK POWER SUPPLY CIRCUIT TO FUEL
PUMP CONTROLLER.
1)Turn the ignition switch to OFF.
2)Disconnect the connector from fuel pump
controller.
3)Turn the ignition switch to ON.
4)Measure the voltage between fuel pump
controller and chassis ground.
Connector & terminal
(R122) No. 10 (+) — Chassis ground ( − − − − ):
2 CHECK GROUND CIRCUIT OF FUEL PUMP
CONTROLLER.
1)Turn the ignition switch to OFF.
2)Measure the resistance of harness between
fuel pump controller and chassis ground.
Connector & terminal
(R122) No. 5 — Chassis ground:
3 CHECK HARNESS BETWEEN FUEL PUMP
CONTROLLER AND FUEL PUMP CONNEC-
TOR.
1)Disconnect the connector from fuel pump.
2)Measure the resistance of harness between
fuel pump controller and fuel pump connector.
Connector & terminal
(R122) No. 7 — (R58) No. 2:
(R122) No. 6 — (R58) No. 1:
4 CHECK HARNESS BETWEEN FUEL PUMP
CONTROLLER AND FUEL PUMP CONNEC-
TOR.
Measure the resistance of harness between
fuel pump controller and chassis ground.
Connector & terminal
(R122) No. 7 — Chassis ground:
(R122) No. 6 — Chassis ground:
Check
Is the voltage more than 10V? Go to step 2.
Is the resistance less than 5
Ω?
Is the resistance less than 1
Ω?
Is the resistance more than 1M
Ω?
EN(TURBO)-311
ENGINE (DIAGNOSTICS)
Yes
Repair the power
supply circuit.
NOTE:
In this case repair
the following:
• Open or ground
short circuit in har-
ness between fuel
pump relay and
fuel pump control-
ler
• Poor contact in
fuel pump control-
ler connector
• Poor contact in
fuel pump relay
connector
Go to step 3. Repair the har-
ness and connec-
tor.
NOTE:
In this case, repair
the following:
• Open circuit
between fuel
pump controller
and chassis
ground
• Poor contact in
fuel pump control-
ler connector
Go to step 4. Repair the open
circuit between
fuel pump control-
ler and fuel pump.
Go to step 5. Repair the ground
short circuit
between fuel
pump controller
and fuel pump.
No