MALFUNCTION OF SUPPLY PUMP SOLENOID VALVE [+B SHORT-CIRCUIT] (DTC CODE P0629 / DIAGNOSIS MONITOR CODE 72)

1. Set the starter key to the "LOCK" position and connect the signal check harness.
2. Disconnect the signal check harness connectors from the ECU.
3. Turn the starter key "ON" and measure voltage between the terminal E7/E27 and the ECU case GND.
   

   

   Standard value: 1 V or less

NO Faulty harness (short-circuit)	YES Proceed to [2] Measuring resistance between terminals

1. Disconnect the supply pump solenoid valve connector.
2. Measure resistance between the terminals E7 and E27 of the signal check harness.
   

   

   Standard value: ∞ Ω

 

NO Faulty harness (short-circuit)	YES Proceed to [3] Inspecting a supply pump solenoid valve

1. Measure resistance between the 1st and 2nd terminals of the supply pump solenoid valve connector (component side).
   

   

   Standard value: 2-3.4 Ω

 

NO Fault in supply pump solenoid valve. Replace.	YES Proceed to [4] Checking of diagnosis code

1. Connect the supply pump solenoid valve connector and the signal check harness connectors on the ECU side. Start the engine.
2. Use the HINO-DX to delete past malfunctions and then check a present malfunction.
3. Replace the engine ECU if the same code is output again. If a normal code is output, there may have been some short-lived abnormalities.
   

   
   

 

1. Confirm the DTC P0629 is inactive

   • Start the engine and let it idling condition.
   • Verify the DTC P0629 is inactive.

   

2. DTC Clear

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

   

P0629 is reoccur: Return to first process Other DTC appear: Refer to concerned Trouble shooting

Complete