Subaru 2009 IMPREZA Service Manual page 1582

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step
1 CHECK SECONDARY AIR COMBINATION
VALVE FUSE.
Check if the secondary air combination valve
fuse (10 A) is blown out.
2 CHECK HARNESS BETWEEN FUSE BOX
AND SECONDARY AIR COMBINATION
VALVE LH CONNECTOR.
1) Remove the secondary air combination
valve fuse (10 A) from the fuse box.
2) Disconnect the connector from the second-
ary air combination valve LH.
3) Measure the resistance between the sec-
ondary air combination valve fuse and second-
ary air combination valve LH connector, and
chassis ground.
Connector & terminal
(F9) No. 5 — Chassis ground:
(E40) No. 2 — Chassis ground:
3 CHECK SECONDARY AIR COMBINATION
VALVE LH OPERATION.
1) Connect the delivery (test) mode connector.
2) Turn the ignition switch to ON.
3) Perform operation check for the secondary
air combination valve LH using the Subaru
Select Monitor.
NOTE:
Refer to "Compulsory Valve Operation Check
Mode" for more operation procedures. <Ref. to
EN(H4DOTC)(diag)-55, Compulsory Valve Op-
eration Check Mode.>
4 CHECK DUCT BETWEEN SECONDARY AIR
PUMP AND SECONDARY AIR COMBINA-
TION VALVE LH.
Check the duct between the secondary air
pump and secondary air combination valve LH.
5 CHECK PIPE BETWEEN SECONDARY AIR
COMBINATION VALVE LH AND CYLINDER
HEAD.
Check the pipe between the secondary air com-
bination valve LH and cylinder head.
6 CHECK POWER SUPPLY TO SECONDARY
AIR COMBINATION VALVE LH.
1) Disconnect the connector from the second-
ary air combination valve LH.
2) In the condition of step 3, measure the volt-
age between secondary air combination valve
LH connector and chassis ground.
Connector & terminal
(E40) No. 2 (+) — Chassis ground (–):
Check
Is the fuse blown out?
Is the resistance 1 M or
more?
Does the secondary air combi-
nation valve LH repeatedly
switch to ON and OFF?
Is there damage, clog or dis-
connection of the duct?
Is there damage, clog or dis-
connection of the pipe?
Does the voltage repeatedly
change between 10 V and 0 V?
EN(H4DOTC)(diag)-361
ENGINE (DIAGNOSTICS)
Yes No
Go to step 2. Go to step 3.
Replace the fuse Repair the ground
with a new part, short circuit of har-
and connect the ness between the
secondary air com- fuse box and the
bination valve LH secondary air com-
connector. bination valve LH
Go to step 3. connector.
Go to step 4. Go to step 6.
Replace, clean or Go to step 5.
connect the duct.
Replace, clean or Even if DTC is
connect the pipe. 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.
Replace the sec- Go to step 7.
ondary air combi-
nation valve LH.
<Ref. to
EC(H4DOTC)-25,
Secondary Air
Combination
Valve.>