Subaru Legacy 2004 Service Manual page 883

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
Step
1 CHECK OPTION CODE.
2 CHECK HARNESS BETWEEN ECM AND
FRONT OXYGEN (A/F) SENSOR CONNEC-
TOR.
1) Turn the ignition switch to ON.
2) Disconnect the connector from front oxygen
(A/F) sensor.
3) Measure the voltage of harness between
ECM connector and chassis ground.
Connector & terminal
(B134) No. 26 (+) — Chassis ground (
(B134) No. 33 (+) — Chassis ground (
Check
Is the option code EC, EK or
K4?
Is the voltage more than 8 V?
"
):
"
):
EN(H4SO 2.5)(diag)-124
Yes
Go to step 2. Refer to EN(H4SO
2.0) section. <Ref.
to EN(H4SO
2.0)(diag)-66, List
of Diagnostic Trou-
ble Code (DTC).>
NOTE:
Fuel injection sys-
tem for KA and KS
model is the same
as 2.0 L model.
Replace the front Repair the battery
oxygen (A/F) sen- short circuit in har-
sor. <Ref. to ness between
FU(H4SO 2.5)-34, ECM and front
Front Oxygen (A/ oxygen (A/F) sen-
F) Sensor.> sor connector.
No