Subaru Legacy 2004 Service Manual page 979

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
Step
7 CHECK OUTPUT SIGNAL FOR ECM.
Measure the voltage between ECM connector
and chassis ground.
Connector & terminal
(B134) No. 33 (+) — Chassis ground (
Check
Is the voltage more than 10 V? Repair the battery
"
):
EN(H4SO 2.5)(diag)-220
Yes
Repair the poor
short circuit in har- contact in ECM
ness between connector.
ECM and front
oxygen (A/F) sen-
sor connector.
After repair,
replace the ECM.
<Ref. to FU(H4SO
2.5)-36, Engine
Control Module
(ECM).>
No