Subaru 2009 IMPREZA Service Manual page 525

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
Step
1 CHECK AIR INTAKE SYSTEM.
2 CHECK MANIFOLD ABSOLUTE PRESSURE
SENSOR.
1) Start the engine and warm up engine until
coolant temperature is higher than 75°C
(167°F).
2) For AT models, set the select lever to "P"
range or "N" range, and for MT models, place
the shift lever in the neutral position.
3) Turn the A/C switch to OFF.
4) Turn all the accessory switches to OFF.
5) Read the data of intake manifold pressure
sensor signal using Subaru Select Monitor or
general scan tool.
NOTE:
• Subaru Select Monitor
For detailed operation procedures, refer to
"READ CURRENT DATA FOR ENGINE". <Ref.
to EN(H4SO)(diag)-34, Subaru Select Moni-
tor.>
• General scan tool
For detailed operation procedures, refer to the
"General Scan Tool Instruction Manual".
3 CHECK THROTTLE OPENING ANGLE.
Read the data of throttle position signal using
Subaru Select Monitor or general scan tool.
NOTE:
• Subaru Select Monitor
For detailed operation procedures, refer to
"READ CURRENT DATA FOR ENGINE". <Ref.
to EN(H4SO)(diag)-34, Subaru Select Moni-
tor.>
• General scan tool
For detailed operation procedures, refer to the
"General Scan Tool Instruction Manual".
4 CHECK THROTTLE OPENING ANGLE.
Check
Are there holes, loose bolts or
disconnection of hose on air
intake system?
Is the measured value 73.3 —
106.6 kPa (550 — 800 mmHg,
21.65 — 31.50 inHg) when the
ignition is turned ON, and 20.0 —
46.7 kPa (150 — 350 mmHg,
5.91 — 13.78 inHg) during
idling?
Is the measured value less than
5% when throttle is fully
closed?
Is the measured value 85% or
more when throttle is fully
open?
EN(H4SO)(diag)-108
Yes No
Repair the air Go to step 2.
intake system.
Go to step 3. Replace the mani-
fold absolute pres-
sure sensor. <Ref.
to FU(H4SO)-33,
Manifold Absolute
Pressure Sensor.>
Go to step 4. Replace the elec-
tronic throttle con-
trol. <Ref. to
FU(H4SO)-14,
Throttle Body.>
Replace the mani- Replace the elec-
fold absolute pres- tronic throttle con-
sure sensor. <Ref. trol. <Ref. to
to FU(H4SO)-33, FU(H4SO)-14,
Manifold Absolute Throttle Body.>
Pressure Sensor.>