MALFUNCTION OF STARTER BLOCK RELAY [+B SHORT-CIRCUIT/OPEN] (DTC CODE P081B / DIAGNOSIS MONITOR CODE 52)

1. Set the starter key to the "LOCK" position and disconnect the starter block relay.
2. Measure continuity between the 1st and 2nd terminals of the starter block relay.
   

   

   Standard: Conducting

    

NO Fault in starter block relay	YES Proceed to [2] Measuring voltage between terminals

1. Set the starter key to the "LOCK" position and connect the signal check harness.
2. Turn the starter key "ON" and measure voltage between the terminals V2 and V79.
   

   

   ECU terminal No.	Description of terminal
   V2	Starter block relay
   V79	GND

   Standard value: 3V or less

    

NO Faulty harness	YES Fault in engine ECU and/or ECU connectors

1. Confirm the DTC P081B is inactive

   • Start the engine and let it idling condition.
   • Verify the DTC P081B is inactive.

   

2. DTC Clear

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

   

P081B is reoccur: Return to first process Other DTC appear: Refer to concerned Trouble shooting

Complete