EN(H4DOTC)(diag)-360
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
15
CHECK REAR OXYGEN SENSOR DATA.
1) Warm up the engine until engine coolant
temperature is higher than 75°C (167°F), and
keep the engine speed at 3,000 rpm. (2 minutes
maximum)
2) Read the value of «Rear O2 Sensor» using
the Subaru Select Monitor or a general scan
tool.
NOTE:
• Depress the clutch pedal.
• Subaru Select Monitor
For detailed operation procedures, refer to
“READ CURRENT DATA FOR ENGINE”. <Ref.
to EN(H4DOTC)(diag)-40, Subaru Select Moni-
tor.>
• General scan tool
For detailed operation procedures, refer to the
general scan tool operation manual.
Is the value of «Rear O2 Sen-
sor» 0.490 V or more?
Go to step
16.
Go to step
17.
16
CHECK REAR OXYGEN SENSOR DATA.
1) Warm up the engine until engine coolant
temperature is higher than 75°C (167°F), and
rapidly reduce the engine speed from 3,000
rpm.
2) Read the value of «Rear O2 Sensor» using
the Subaru Select Monitor or a general scan
tool.
NOTE:
• Depress the clutch pedal.
• Subaru Select Monitor
For detailed operation procedures, refer to
“READ CURRENT DATA FOR ENGINE”. <Ref.
to EN(H4DOTC)(diag)-40, Subaru Select Moni-
tor.>
• General scan tool
For detailed operation procedures, refer to the
general scan tool operation manual.
Is the value of «Rear O2 Sen-
sor» 0.250 V or less?
Go to step
18.
Go to step
17.
17
CHECK REAR OXYGEN SENSOR CONNEC-
TOR AND COUPLING CONNECTOR.
Has water entered the connec-
tor?
Completely
remove any water
inside.
Go to step
19.
18
CHECK FRONT OXYGEN (A/F) SENSOR US-
ING REAR OXYGEN SENSOR SIGNAL.
1) Warm up the engine until engine coolant
temperature is higher than 75°C (167°F), then
keep the engine idling for 5 minutes or more.
2) Read the value of «Rear O2 Sensor» using
the Subaru Select Monitor or a general scan
tool.
NOTE:
• Subaru Select Monitor
For detailed operation procedures, refer to
“READ CURRENT DATA FOR ENGINE”. <Ref.
to EN(H4DOTC)(diag)-40, Subaru Select Moni-
tor.>
• General scan tool
For detailed operation procedures, refer to the
general scan tool operation manual.
Is the value in «Rear O2 Sen-
sor» kept at 0.250 V or less for
5 minutes or more?
Replace the front
oxygen (A/F) sen-
sor. <Ref. to
FU(STI)-54, Front
Oxygen (A/F) Sen-
sor.> <Ref. to
FU(w/o STI)-53,
Front Oxygen (A/F)
Sensor.>
Go to step
19.
Step
Check
Yes
No