Subaru 2009 IMPREZA Service Manual page 1574

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step
1 CHECK CURRENT DATA.
1) Turn the ignition switch to ON.
2) Read the data of secondary air piping pres-
sure signal using Subaru Select Monitor or gen-
eral scan tool.
NOTE:
• Subaru Select Monitor
For detailed operation procedures, refer to
"READ CURRENT DATA FOR ENGINE". <Ref.
to EN(H4DOTC)(diag)-34, Subaru Select Moni-
tor.>
• General scan tool
For detailed operation procedures, refer to the
general scan tool operation manual.
2 CHECK HARNESS BETWEEN ECM AND
SECONDARY AIR COMBINATION VALVE
RH CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from the second-
ary air combination valve RH.
3) Turn the ignition switch to ON.
4) Read the data of secondary air piping pres-
sure signal using Subaru Select Monitor or gen-
eral scan tool.
NOTE:
• Subaru Select Monitor
For detailed operation procedures, refer to
"READ CURRENT DATA FOR ENGINE". <Ref.
to EN(H4DOTC)(diag)-34, Subaru Select Moni-
tor.>
• General scan tool
For detailed operation procedures, refer to the
general scan tool operation manual.
3 CHECK HARNESS BETWEEN ECM AND
SECONDARY AIR COMBINATION VALVE
RH CONNECTOR.
1) Turn the ignition switch to OFF.
2) Measure the resistance of the harness
between the secondary air combination valve
RH connector and engine ground.
Connector & terminal
(E41) No. 3 — Engine ground:
4 CHECK POOR CONTACT.
Check for poor contact of secondary air combi-
nation valve RH connector.
Check
Is the measured value 133.3 kPa
(1000 mmHg, 39.4 inHg) or
more?
Is the measured value 133.3 kPa
(1000 mmHg, 39.4 inHg) or
more?
Is the resistance less than 5 ? Go to step 4.
Is there poor contact of second-
ary air combination valve RH
connector?
EN(H4DOTC)(diag)-353
ENGINE (DIAGNOSTICS)
Yes No
Go to step 2. Even if DTC is
detected, the cir-
cuit has returned to
a normal condition
at this time. Repro-
duce the failure,
and then perform
the diagnosis
again.
NOTE:
In this case, tem-
porary poor con-
tact of connector
may be the cause.
Repair the short Go to step 3.
circuit to power in
the harness
between ECM and
secondary air com-
bination valve RH
connectors.
Repair the harness
and connector.
NOTE:
In this case, repair
the following item:
• Open circuit in
harness between
ECM and second-
ary air combination
valve RH connec-
tor
• Poor contact of
ECM connector
• Poor contact of
coupling connector
Repair the poor Replace the sec-
contact of second- ondary air combi-
ary air combination nation valve RH.
valve RH connec- <Ref. to
tor. EC(H4DOTC)-25,
Secondary Air
Combination
Valve.>