Subaru 2004 LEGACY Service Manual page 28

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step
1 CHECK INPUT SIGNAL FROM ECM.
Measure the voltage between ECM connector
and chassis ground.
Connector & terminal
(B135) No. 3 (+) — Chassis ground (
2 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 or the
OBD-II general scan tool.
NOTE:
• Subaru Select Monitor
For detailed operation procedures, refer to the
"READ CURRENT DATA SHOWN ON DIS-
PLAY FOR ENGINE". <Ref. to
EN(H6DO)(diag)-25, Subaru Select Monitor.>
• OBD-II general scan tool
For detailed operation procedures, refer to the
OBD-II General Scan Tool Operation Manual.
3 CHECK POOR CONTACT.
Check poor contact in ECM connector.
Check
Is the voltage more than 8 V?
−
):
Is the current more than 7 A?
Is the poor contact in ECM
connector?
EN(H6DO)(diag)-97
ENGINE (DIAGNOSTICS)
Yes
Go to step 2. Go to step 3.
Replace the ECM. END.
<Ref. to
FU(H6DO)-34,
Engine Control
Module (ECM).>
Repair the poor END.
contact in ECM
connector.
No