Subaru Legacy 2005 Service Manual page 1792

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
Step
1 CHECK OUTPUT SIGNAL FROM ECM.
1) Turn the ignition switch to ON.
2) Measure the voltage between ECM con-
nector and chassis ground.
Connector & terminal
(B134) No. 1 (+) — Chassis ground (
(B135) No. 7 (+) — Chassis ground (
2 CHECK FRONT OXYGEN (A/F) SENSOR
HEATER CURRENT.
1) Turn the ignition switch to OFF.
2) Repair the battery short circuit of harness
between ECM and front oxygen (A/F) sensor
connector.
3) Turn the ignition switch to ON.
4) Read the data of front oxygen (A/F) sensor
heater current using Subaru Select Monitor or
general scan tool.
NOTE:
• Subaru Select Monitor
For detailed operation procedure, refer to
"READ CURRENT DATA FOR ENGINE". <Ref.
to EN(H6DO)(diag)-26, Subaru Select Moni-
tor.>
• General scan tool
For detailed operation procedure, refer to the
general scan tool operation manual.
3 CHECK OUTPUT SIGNAL FROM ECM.
Measure the voltage between ECM connector
and chassis ground.
Connector & terminal
(B134) No. 1 (+) — Chassis ground (
(B135) No. 7 (+) — Chassis ground (
Check
Is the voltage more than 8 V?
−
):
−
):
Is the current more than 2.3 A? Replace the ECM.
Does the voltage change by
shaking the ECM harness and
connector?
−
):
−
):
EN(H6DO)(diag)-96
Yes
Go to step 2. Go to step 3.
Finish the diagno-
<Ref. to sis.
FU(H6DO)-34,
Engine Control
Module (ECM).>
Repair the battery Finish the diagno-
short circuit of har- sis.
ness between
ECM and front
oxygen (A/F) sen-
sor connector.
No