Subaru Forester 2004 Service Manual page 80

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step
1 CHECK INPUT SIGNAL FROM ECM.
1) Turn the ignition switch to OFF.
2) Measure the voltage between ECM con-
nector and chassis ground.
Connector & terminal
(B135) No. 2 (+) — Chassis ground (
2 CHECK CURRENT DATA.
1) Repair battery short circuit in harness
between ECM and rear oxygen sensor con-
nector.
2) Turn the ignition switch to ON.
3) Read the data of rear oxygen (A/F) sensor
heater current using Subaru Select Monitor or
OBD-II general scan tool.
NOTE:
• Subaru Select Monitor
For detailed operation procedure, refer to
"READ CURRENT DATA SHOWN ON DIS-
PLAY FOR ENGINE". <Ref. to EN(H4DOTC
2.5)-27, 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 there poor contact in ECM
connector?
EN(H4DOTC 2.5)-79
ENGINE (DIAGNOSTIC)
Yes
Go to step 2. Go to step 3.
Replace the ECM. END.
<Ref. to
FU(H4DOTC 2.5)-
41, Engine Con-
trol Module
(ECM).>
Repair the poor END.
contact in ECM
connector.
No