Subaru Legacy (2005 year). Manual - part 129
EN(H4SO 2.0)(diag)-105
ENGINE (DIAGNOSTICS)
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step
Check
Yes
No
1
CHECK ANY OTHER DTC ON DISPLAY.
Is any other DTC displayed?
Check DTC using
“List of Diagnostic
Trouble Code
(DTC)”. <Ref. to
EN(H4SO
2.0)(diag)-64, List
of Diagnostic Trou-
ble Code (DTC).>
2
CHECK FRONT OXYGEN (A/F) SENSOR DA-
TA.
1) Start the engine.
2) While observing the Subaru Select Monitor
or general scan tool screen, warm-up the
engine until engine coolant temperature is
above 70
°C (160°F).
If the engine is already warmed-up, operate at
idle speed for at least 1 minute.
3) Read the data of front oxygen (A/F) sensor
signal 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(H4SO 2.0)(diag)-25, Subaru Select
Monitor.>
• General scan tool
For detailed operation procedure, refer to the
general scan tool operation manual.
Is the voltage 0.85 — 1.15 V?
3
CHECK FRONT OXYGEN (A/F) SENSOR DA-
TA.
1) Race the engine at speed from idling to
5,000 rpm for a total of 5 cycles.
2) Read the data of front oxygen (A/F) sensor
signal during racing using Subaru Select Moni-
tor or general scan tool.
NOTE:
• Air fuel ratio is rich at normal condition or
during racing.
• To increase engine speed to 5,000 rpm,
slowly depress accelerator pedal, taking
approximately 5 seconds, and quickly release
accelerator pedal to decrease engine speed.
• Subaru Select Monitor
For detailed operation procedure, refer to
“READ CURRENT DATA FOR ENGINE”. <Ref.
to EN(H4SO 2.0)(diag)-25, Subaru Select
Monitor.>
• General scan tool
For detailed operation procedure, refer to the
general scan tool operation manual.
Is the voltage more than 1.1 V? Go to step 6.