Subaru Legacy 2004 Service Manual page 850

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step
1 CHECK OPTION CODE.
2 CHECK INPUT SIGNAL FROM ECM.
Measure the voltage between ECM connector
and chassis ground.
Connector & terminal
(B135) No. 2 (+) — Chassis ground (
3 CHECK CURRENT DATA.
1) Turn the ignition switch to OFF.
2) Repair the battery short circuit in harness
between ECM and rear oxygen sensor con-
nector.
3) Turn the ignition switch to ON.
4) Read the data of rear oxygen sensor heater
current using Subaru Select Monitor.
NOTE:
For detailed operation procedure, refer to the
"READ CURRENT DATA FOR ENGINE". <Ref.
to EN(H4SO 2.5)(diag)-26, Subaru Select Mon-
itor.>
4 CHECK POOR CONTACT.
Check poor contact in ECM connector.
Check
Is the option code EC, EK or
K4?
Is the voltage more than 8 V?
"
):
Is the current more than 7 A?
Is there poor contact in ECM
connector?
EN(H4SO 2.5)(diag)-91
ENGINE (DIAGNOSTICS)
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.
Go to step 3. Go to step 4.
Replace the ECM. END.
<Ref. to FU(H4SO
2.5)-36, Engine
Control Module
(ECM).>
Repair the poor END.
contact in ECM
connector.
No