MALFUNCTION OF DIESEL THROTTLE POSITION SENSOR [HI]
(DTC CODE P0123 / DIAGNOSIS MONITOR CODE 32)

1. Set the starter key to the "LOCK" position and disconnect the diesel throttle position sensor connector.
2. Measure resistance between the 5th and 6th terminals of the diesel throttle position sensor (component side).

   
   

   
   

   Standard value: Approximately 180 Ω

   

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

3. Measure resistance between the 3rd and 5th terminals of the diesel throttle position sensor (component side).

   
   

   Standard value: Approximately 3 kΩ

    

4. Measure resistance between the 3rd and 6th terminals of the diesel throttle position sensor (component side).

   
   

   Standard value: Approximately 3 kΩ

    

NO Fault in diesel throttle position sensor	YES Proceed to [2] Measuring resistance between sensor terminals

1. Measure resistance between the 3rd and 6th terminals of the diesel throttle position sensor (vehicle harness side).

   
   

   Standard value: Approximately 25-35 kΩ

 

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

1. Measure resistance between the 5th and 6th terminals of the diesel throttle position sensor (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 E33 and V92.

   
   

   

   ECU terminal No.	Description of terminal
   E33	Sensor power supply
   V92	D throttle valve opening sensor

   Standard value: ∞ Ω

    

NO Fault in engine ECU	YES Proceed to [5] Measuring resistance between terminals

1. Connect the diesel throttle position sensor connector.
2. Connect the signal check harness connectors to the vehicle harness.
3. Disconnect the signal check harness connectors from the ECU and measure resistance between the terminals E33 and E92.



 

ECU terminal No.	Description of terminal
E33	Sensor power supply
V92	D throttle valve opening sensor

Standard value: 2 Ω or more

 

NO Faulty harness or fault in diesel throttle position sensor	YES Proceed to [6] Measuring resistance between terminals

1. Measure resistance between the terminals V91 and V92.

   

   ECU terminal No.	Description of terminal
   V91	GND
   V92	D throttle valve opening sensor

   Standard value: Approximately 3 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 P0122 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 P0123 is inactive

   • Start the engine and let it idling condition.
   • Verify the DTC P0123 is inactive.

   

2. DTC Clear

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

   

P0123 is reoccur: Return to first process Other DTC appear: Refer to concerned Trouble shooting

Complete