Subaru 2009 IMPREZA, Service Manual

Page: 619 / 3619

EN(H4SO)(diag)-202
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
3 CHECK WAVEFORM DATA ON THE SUBA-
RU SELECT MONITOR (WHILE IDLING).
1) Run the engine at idle.
2) In the condition of step 1), use the Subaru
Select Monitor to read the waveform data.
• At normal condition
• At abnormal condition 1 (numerous inversion)
• At abnormal condition 2 (noise input)
Is a normal waveform dis-
played? Go to step 4 . • The waveform is
displayed at abnor-
mal condition 1:Go
to step
4 .
• The waveform is
displayed at abnor-
mal condition 2:Go
to step
5 .
4 CHECK CATALYTIC CONVERTER. Is the catalytic converter dam-
aged? Replace the cata-
lytic converter.
<Ref. to
EC(H4SO)-3,
Front Catalytic
Converter.> Go to step 5 .
5 CHECK REAR OXYGEN SENSOR CONNEC-
TOR AND COUPLING CONNECTOR. Has water entered the connec-
tor? Completely
remove any water
inside. Go to step 6 .
Step Check Yes No
EN-06668
1
0
10 sec/div
REAR OXYGEN
SENSOR VOLTAGE
(V)
EN-06669
1
0
10 sec/div
REAR OXYGEN
SENSOR VOLTAGE
(V)
EN-06670
1
0
10 sec/div
REAR OXYGEN
SENSOR VOLTAGE
(V)