Vehicle Speed Signal Circuit between Navigation ECU and Multi-Display: Wiring Diagram

1. Enter the "Display Check Mode (Vehicle Signal Check)" (See DISPLAY CHECK MODE  ).
2. While driving, compare the "Speed" indicator to the reading on the speedometer. Check if these readings are almost the same.

   OK: The readings are almost the same. 

   Fig 2: Display Check Mode (Vehicle Signal Check)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: GO TO " VEHICLE SPEED SIGNAL CIRCUIT BETWEEN MULTI-DISPLAY AND COMBINATION METER  " 

OK: Go to next step. 

1. Disconnect the navigation ECU connector p2.
2. Measure voltage.
   1. Jack up either one of the drive wheels.
   2. Move the shift lever to the neutral position.
   3. Turn the engine switch on (IG).
      Fig 3: Identifying Navigation ECU Connector p2

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   4. Measure the voltage between terminal SPD of the navigation ECU and body ground when the drive wheels are turned slowly.

      OK: Voltage pulses as shown in the illustration. 

      Fig 4: View Of Voltage Pulses/Blinking Pattern

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

OK: REPLACE NAVIGATION ECU 

NG: Go to next step. 

1. Disconnect the multi-display connector p1 and navigation ECU connector p2.
2. Measure the resistance according to the value(s) in the table below.
   STANDARD RESISTANCE
   
   

   Tester connection	Condition	Specified condition
   SPD2 - SPD	Always	Below 1 Ω
   SPD2 - Body ground	Always	10 kΩ or higher

Fig 5: Identifying Multi-Display Connector p1 And Navigation ECU Connector p2

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: REPLACE MULTI-DISPLAY