DTC P0720/61 VEHICLE SPEED SENSOR NO. 2 SYSTEM

1. Set the ignition switch to ON.
2. Check the voltage between the terminals of the transmission control computer.

   Standard:

   Terminal No. (terminal symbol)	Measuring condition	Voltage [V]
   B1 (SP2+) ↔ B8 (GND1)	Engine at idle speed	7-9

   
   

   To step 3

   Proceed to [2]INSPECT TRANSMISSION CONTROL COMPUTER ASSY BY ITSELF (INSPECT WAVEFORM)

1. Connect an oscilloscope between terminals B2 (SP2-) and B8 (GND1) of the transmission control computer ASSY.
2. Inspect the waveform between the terminals of the transmission control computer ASSY.

   Standard:

   Item	Contents
   Measuring terminal	SP2- ↔ GND1
   Instrument setting	500mv/DIV, 2ms/DIV
   Measuring condition	Running with vehicle speed of 20 km/h

   
   

   

   The waveform cycle becomes shorter with increasing vehicle speed.

   Inspect and replace the transmission control computer ASSY.

   Proceed to [3]INSPECT WIRE HARNESS AND CONNECTOR (SPEED SENSOR (SP2) - TRANSMISSION CONTROL COMPUTER ASSY)

1. Inspect conductivity
   1. Connect the connector of the speed sensor (SP2) and disconnect connector B of the transmission control computer ASSY.
   2. Check the conductivity between the connector on the wire harness side of the transmission control computer ASSY and the connector on the wire harness side of the speed sensor (SP2). (Refer to page for the terminal layout.)

      Standard:

      Terminal No. (terminal symbol) (Transmission computer ↔ speed sensor)	Conductivity
      B1 (SP2+) ↔ 1 (SP2+)	Yes
      C1 (NT-) ↔ 2 (SP2-)	Yes

2. Inspect Insulation
   1. Check the insulation between the connector on the wire harness side of the transmission control computer ASSY and body earth. (Refer to page for the terminal layout.)

      Standard:

      Terminal No. (terminal symbol) (Transmission computer)	Conductivity
      B1 (SP2+) ↔ Body earth	No
      C1 (NT-) ↔ Body earth	No

   Repair or replace wire harness and connector.

   Replace the speedsensor (SP2).

1. Confirm the DTC P0720/61 is inactive

   • Start the engine and let it idling condition.
   • Verify the DTC P0720/61 is inactive.

   

2. DTC Clear

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

   

P0720/61 is reoccurF Return to first process Other DTC appearF Refer to concerned Trouble shooting

Complete