DTC P0068 Map/MAF - Throttle Position Correlation: Notes

DTC detecting condition: 

Detected when two consecutive driving cycles with fault occur.

1. CHECK AIR INTAKE SYSTEM. 

   Are there holes, loose bolts or disconnection of hose on air intake system?

   • Yes: Repair the air intake system.
   • No: Go to 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. For CVT 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. Using the Subaru Select Monitor or a general scan tool, read the value of [Mani. Absolute Pressure].
   NOTE:

   • Subaru Select Monitor

     For detailed procedures, refer to "Data Monitor". Ref. to ENGINE (DIAGNOSTICS) (H4DO)>Subaru Select Monitor .

   • General scan tool

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

   Is the value of [Mani. Absolute Pressure] 73.3 - 106.6 kPa (550 - 800 mmHg, 21.65 - 31.50 inHg) at ignition ON, and 20.0 - 46.7 kPa (150 - 350 mmHg, 5.91 - 13.78 inHg) at idling?

   • Yes: Go to 3. 
   • No: Replace the manifold absolute pressure sensor. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>Manifold Absolute Pressure Sensor .
3. CHECK THROTTLE OPENING ANGLE. 

   Using the Subaru Select Monitor or a general scan tool, read the value of [Throttle Opening Angle].

   NOTE:

   • Subaru Select Monitor

     For detailed procedures, refer to "Data Monitor". Ref. to ENGINE (DIAGNOSTICS) (H4DO)>Subaru Select Monitor .

   • General scan tool

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

   Is the value of [Throttle Opening Angle] less than 5% when throttle is fully closed?

   • Yes: Go to 4. 
   • No: Replace the electronic throttle control. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>Throttle Body .
4. CHECK THROTTLE OPENING ANGLE. 

   Is the value of [Throttle Opening Angle] 85% or more when throttle is fully open?

   • Yes: Replace the manifold absolute pressure sensor. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>Manifold Absolute Pressure Sensor .
   • No: Replace the electronic throttle control. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO)>Throttle Body .