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. 

   Check the 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. 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. Read the value of «Mani. Absolute Pressure» using the Subaru Select Monitor or a general scan tool.
      NOTE:

      • Subaru Select Monitor

        For detailed operation procedures, refer to "Current Data Display For Engine". Ref. to ENGINE (DIAGNOSTICS) (H4DO)>SUBARU SELECT MONITOR

      • General scan tool

        For detailed operation procedures, refer to the general scan tool operation 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?

   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 in «Throttle Opening Angle».

   NOTE:

   • Subaru Select Monitor

     For detailed operation procedures, refer to "Current Data Display For Engine". Ref. to ENGINE (DIAGNOSTICS) (H4DO)>SUBARU SELECT MONITOR

   • General scan tool

     For detailed operation procedures, refer to the general scan tool operation manual.

   Is the value in «Throttle Opening Angle» with the throttle fully closed less than 5%?

   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 in «Throttle Opening Angle» with the throttle fully open 85% or more?

   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