Code No. P0068: Trustful Check Manifold Absolute Pressure Sensor

FUNCTION

• Compare the actual measurement of manifold absolute pressure by an manifold absolute pressure sensor signal with manifold absolute pressure estimated from a throttle position sensor (main or sub) signal.
  

TROUBLE JUDGEMENT

• While engine is running.
  
• Throttle position sensor (main and sub) are normal.
  
• Manifold absolute pressure sensor is normal.
  

• Difference is less than specified value between manifold absolute pressure of supposed throttle position sensor (main) signal and that of supposed throttle position sensor (sub) signal.
  
• Difference is more than specified value between manifold absolute pressure of actual manifold absolute pressure sensor reading and that of supposed throttle position sensor (main) signal.
  
• Difference is more than specified value between manifold absolute pressure of actual manifold absolute pressure sensor reading and that of supposed throttle position sensor (sub) signal.
  

FAIL-SAFE AND BACKUP FUNCTION

• Fuel control is carried out using throttle opening degree and engine speed in accordance with preset map.
  

PROBABLE CAUSES

• Failed manifold absolute pressure sensor
  
• Harness damage in manifold absolute pressure sensor circuit or loose connector contact
  
• Failed intake air system
  
• Failed engine-ECU
  

	Inspection chart for diagnosis code (Refer to ).

	Go to Step 2.

	Go to Step 3.

	Check manifold absolute pressure sensor system. Check code No. P0107: manifold absolute pressure sensor circuit low input (Refer to ). Check code No. P0108: manifold absolute pressure sensor circuit high input (Refer to ).

	Go to Step 4.

	Repair.

	Replace the engine-ECU.

	Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).