EN(H4DOTC)(diag)-349
Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
Step
Check
Yes
No
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 procedure, 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.
Is the measured value less than
53.3 kPa (400 mmHg, 15.8 inHg)?
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.
2
CHECK POWER SUPPLY OF SECONDARY
AIR COMBINATION VALVE RH.
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) Measure the voltage between the second-
ary air combination valve RH connector and
chassis ground.
Connector & terminal
(E41) No. 1 (+) — Chassis ground (–):
Is the voltage 4.5 V or more?
Go to step 3.
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 in
ECM connector
• Poor contact of
coupling connector
3
CHECK HARNESS BETWEEN ECM AND
SECONDARY AIR COMBINATION VALVE
RH CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from ECM.
3) Measure the resistance of the harness
between the ECM and secondary air combina-
tion valve RH connector.
Connector & terminal
(B134) No. 27 — (E41) No. 2:
Is the resistance less than 1
:? Go to step 4.
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
coupling connector
4
CHECK HARNESS BETWEEN ECM AND
SECONDARY AIR COMBINATION VALVE
RH CONNECTOR.
Measure the resistance between ECM and
chassis ground.
Connector & terminal
(B134) No. 27 — Chassis ground:
Is the resistance 1 M
: or
more?
Go to step 5.
Repair the ground
short circuit of har-
ness between
ECM and second-
ary air combination
valve RH connec-
tor.
5
CHECK POOR CONTACT.
Check for poor contact in the ECM and second-
ary air combination valve RH connector.
Is there poor contact in the
ECM or secondary air combi-
nation valve RH connector?
Repair the poor
contact in the ECM
or secondary air
combination valve
RH connector.
Replace the sec-
ondary air combi-
nation valve RH.
<Ref. to
EC(H4DOTC)-22,
Secondary Air
Combination
Valve.>