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Diagnostic Procedure

WARNING: This page is about a different car, the 2013 Subaru Forester. However, it is still accessible from the selected car via links, so may be relevant.
DIAGNOSTIC PROCEDURE

Step Check Yes No
1 CHECK AIR INTAKE SYSTEM.  Are there holes, loose bolts or disconnection of hose on air intake system? Repair the air intake system. Go to step 2. 
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. Place the select lever in "P" range or "N" range.
  3. Turn the A/C switch to OFF.
  4. Turn all the accessory switches to OFF.
  5. Using the Subaru Select Monitor or a general scan tool, read the value in «Mani. Absolute Pressure».
NOTE:
  • Subaru Select Monitor

    For detailed operation procedures, refer to "READ CURRENT DATA FOR ENGINE". < Refer to SUBARU SELECT MONITOR . >

  • General scan tool

    For detailed operation procedures, refer to the "General Scan Tool Instruction Manual".

 Is the value in «Mani. Absolute Pressure» 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? Go to step 3.  Replace the manifold absolute pressure sensor. < Refer to MANIFOLD ABSOLUTE PRESSURE SENSOR . >
3 CHECK THROTTLE OPENING ANGLE. 
Using the Subaru Select Monitor or a general scan tool, read the value in «Throttle Opening Angle».
NOTE:
  • Subaru Select Monitor

    For detailed operation procedures, refer to "READ CURRENT DATA FOR ENGINE". < Refer to SUBARU SELECT MONITOR . >

  • General scan tool

    For detailed operation procedures, refer to the "General Scan Tool Instruction Manual".

 Is the value in «Throttle Opening Angle» with the throttle fully closed less than 5%? Go to step 4.  Replace the electronic throttle control. < Refer to THROTTLE BODY . >
4 CHECK THROTTLE OPENING ANGLE.  Is the value in «Throttle Opening Angle» with the throttle fully open 85% or more? Replace the manifold absolute pressure sensor. < Refer to MANIFOLD ABSOLUTE PRESSURE SENSOR . > Replace the electronic throttle control. < Refer to THROTTLE BODY . >
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