FAILURE IN SENSOR POWER SUPPLY
(DTC CODE P0642 / DIAGNOSIS MONITOR CODE 5)

1. Disconnect the common rail pressure sensor connector, accelerator sensor connector, differential pressure sensor connector and operational accelerator sensor connector one by one. Inspect a connector disconnected just before the DTC code P0642 goes out.
   
   

   

   If a fault occurs in the sensor power supply 2, the DTC codes P1198, P1418 and P2122 will be indicated besides the DTC code P0642.

    

NO Go to [2] Measuring continuity between terminals.	YES Proceed to [2] 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.
3. Measure resistance between the terminal E13/E25/E33/V71/V83 and the terminal E56.
   

   

   ECU terminal No.	Description of terminal
   E13, E25, E33, V71, V83	Sensor power supply
   E56	GND

   Standard value: ∞ Ω

    

NO Faulty harness	YES Fault in engine ECU

1. Confirm the DTC P0642 is inactive

   • Start the engine and let it idling condition.
   • Verify the DTC P0642 is inactive.

   

2. DTC Clear

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

   

P0642 is reoccur: Return to first process Other DTC appear: Refer to concerned Trouble shooting

Complete