ABNORMAL PRESSURE DIFFERENCE
[ATMOSPHERIC PRESSURE & INTAKE AIR PRESSURE]
(DTC CODE P0069 / DIAGNOSIS MONITOR CODE A5)

1.Inspecting atmospheric pressure and intake air pressure

1. Turn the starter key to the "ON" position and display the ECU data monitor according to the Hino-DX screen display to read the atmospheric pressure and intake air pressure.

   Standard value:
   101 kPa (Normal atmospheric pressure on the flat ground)

    
   • Variable depending on altitude.
    

   Result of activation	step
   Only intake air pressure is abnormally high	Go to YES
   Only atmospheric pressure is abnormally high	Go to NO

 

NO Replace the engine ECU

YES Proceed to [2] Measuring voltage between terminals

2.Measuring voltage between terminals

1. Measure voltage between the 1st and 2nd terminals of the intake air pressure sensor connector.
    

   Standard value
   When negative pressure of 40 kPa is applied on the flat ground: 0.1-0.7 V
   When open to the ambient air (atmospheric pressure at 101.3 kPa): 0.8-1.5 V
   When positive pressure of 70 kPa is applied on the flat ground (absolute value of 70 kPa): 1.6-2.3 V

 

NO Replace the intake air pressure sensor

YES Proceed to [3] Measuring resistance between terminals

3.Measuring resistance between terminals

1. Turn the starter key to the "LOCK" position and disconnect the engine ECU connector and intake air pressure sensor connector.
    
2. Measure resistance between the terminals of the engine ECU connector (vehicle wire harness side) and intake air pressure sensor connector (vehicle wire harness side).
    

   Engine ECU (Vehicle wire harness side)	Intake air pressure sensor (Vehicle wire harness side)
   5th terminal	2nd terminal
   13th terminal	3rd terminal
   14th terminal	1st terminal

   Standard value: Less than 1 Ω

3. Measure resistance between the 5th terminal, 14th terminal and other terminal of the engine ECU connector (vehicle wire harness side) and the body GND.
    

   Standard value: 10 kΩ or more

4. Measure resistance between the 2nd, 3rd and other terminals of the intake air pressure sensor connector (vehicle wire harness side) and the body GND.
    

   Standard value: 10 kΩ or more

5. Measure resistance between the 14th terminal and the other terminal of the engine ECU connector (vehicle wire harness side).
    

   Standard value: 10 kΩ or more

6. Measure resistance between the 1st and other terminals of the intake air pressure sensor connector (vehicle wire harness side).
      

   Standard value: 10 kΩ or more

NO Repair or replace the wire harness or connector.

YES Replace the engine ECU

DTC Clear

Detail

1. Confirm the DTC P0069 is inactive

   • Start the engine and let it idling condition.
   • Verify the DTC P0069 is inactive.

    

2. DTC Clear

   • Clear the DTC with Hino DX
   • Confirm the same DTC is not reoccurred

    

NO P0069 is reoccur: Return to first process Other DTC appear: Refer to concerned Trouble shooting

YES Complete