Subaru 2009 IMPREZA Service Manual page 1568

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step
1 CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed?
2 CHECK CURRENT DATA.
1) Turn the ignition switch to ON (engine OFF).
2) Using the Subaru Select Monitor, read sec-
ondary air piping pressure, intake pipe absolute
pressure and atmospheric pressure, and com-
pare with the actual atmospheric pressure.
NOTE:
For detailed operation procedures, refer to
"READ CURRENT DATA FOR ENGINE". <Ref.
to EN(H4DOTC)(diag)-34, Subaru Select Moni-
tor.>
Check
Is the actual difference with
atmospheric pressure
200 mmHg (27 kPa, 8 inHg,
3.9 psig) or more?
EN(H4DOTC)(diag)-347
ENGINE (DIAGNOSTICS)
Yes No
Check the appropri- Go to step 2.
ate DTC using the
"List of Diagnostic
Trouble Code
(DTC)". <Ref. to
EN(H4DOTC)(diag)
-83, List of Diagnos-
tic Trouble Code
(DTC).>
Replace the sec- Even if DTC is
ondary air combi- detected, the cir-
nation valve RH. cuit has returned to
<Ref. to a normal condition
EC(H4DOTC)-25, at this time. Repro-
Secondary Air duce the failure,
Combination and then perform
Valve.> the diagnosis
again.
NOTE:
In this case, tem-
porary poor con-
tact of connector
may be the cause.