MALFUNCTION OF BOOST PRESSURE SENSOR [HI]
(DTC CODE P0108 / DIAGNOSIS MONITOR CODE 25)

1. Set the starter key to the "LOCK" position and disconnect the boost pressure sensor connector.
2. Measure resistance between the 2nd and 3rd terminals of the boost pressure sensor connector (component side).
   

    

   
   

 

Standard value: 2-15 kΩ



If it is difficult to troubleshoot the connector itself, go to [5] Measuring resistance between terminals.

 

 

NO Fault in boost pressure sensor	YES Proceed to [2] Measuring resistance between sensor terminals

1. Measure resistance between the 1st and 2nd terminals of the boost pressure sensor connector (vehicle harness side).
   

    

   

   
   Standard value: 209-231 kΩ

 

NO Faulty harness or irregular contact of connector	YES Proceed to [3] Measuring resistance between terminals

1. Measure resistance between the 2nd and 3rd terminals of the boost pressure sensor connector (vehicle harness side).
   
   

   
   

   

   
   Standard value: ∞ Ω

 

NO Faulty harness	YES Proceed to [4] Measuring resistance between terminals

1. Set the starter key to the "LOCK" position and connect the signal check harness.
2. Disconnect the signal check harness connectors from the vehicle harness and measure resistance between the terminals V81 and V83.
   

   

   ECU terminal No.	Description of terminal
   V81	Boost pressure sensor SIG
   V83	Sensor power supply

   Standard value: ∞ Ω

NO Faulty harness	YES Proceed to [5] Measuring resistance between terminals

1. Connect the connector of the boost pressure sensor.
2. Connect the signal check harness connectors to the vehicle harness.
3. Disconnect the signal check harness connectors from the ECU.
4. Measure resistance between the terminals V81 and V83.
   
   

   
   

   

    

   Standard value: 2-15 kΩ
   

 

NO Fault in boost pressure sensor or faulty harness	YES Proceed to [6] Measuring resistance between terminals

1. Measure resistance between the terminals V81 and V82.
   

   

   ECU terminal No.	Description of terminal
   V81	Boost pressure sensor SIG
   V82	GND

   Standard value: 2-15 kΩ

NO Faulty harness or irregular contact of connector	YES Proceed to [7] Checking of diagnosis code

1. Connect the signal check harness connectors to the ECU.
2. Turn the starter key "ON" and check DTC codes.
   
   

   Standard: The DTC code P0237 must be output.
   

NO Fault in engine ECU	YES Use HINO-DX to delete past malfunctions and then output diagnosis codes again.

1. Confirm the DTC P0108 is inactive

   • Start the engine and let it idling condition.
   • Verify the DTC P0108 is inactive.

   

2. DTC Clear

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

   

P0108 is reoccur: Return to first process Other DTC appear: Refer to concerned Trouble shooting

Complete