DTC B15C2: Speed Signal Malfunction: Procedure

1. Enter the "Vehicle Sensors" screen. Refer to Check GPS & Vehicle Sensors in Operation Check. Refer to OPERATION CHECK .
   Fig 1: Screen Display - GPS & Vehicle Sensor

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. While driving the vehicle, compare the "Speed" indicator to the reading on the speedometer. Check if these readings are almost equal.

   HINT: 

   The combination meter assembly receives the vehicle speed signal from the skid control ECU via CAN communication. Therefore, perform the following inspection referring to values on the Data List of the skid control ECU because it is the source of the vehicle speed signal.

   OK

   Vehicle speed displayed on the "Vehicle Sensors" screen is almost the same as the actual vehicle speed measured using the Techstream. Refer to DATA LIST / ACTIVE TEST .

NG → See step   2 

OK → See step   4 

1. Check the output waveform.
   Fig 2: Checking Combination Meter Assembly With Waveform Reference

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   1. Remove the combination meter assembly with the connector(s) still connected.
   2. Connect an oscilloscope to terminal D18-10 (+S) and body ground.
   3. Turn the ignition switch to ON.
   4. Turn a wheel slowly.
   5. Check the signal waveform according to the condition(s) in the table below.

      Item	Condition
      Measurement terminal	D18-10 (+S) - Body ground
      Tool setting	5 V/DIV., 20 ms./DIV.
      Vehicle condition	Wheel being rotated

      TEXT IN ILLUSTRATION
      
      

      *a	Component with harness connected (Combination Meter Assembly)

      OK

      The waveform display is as shown in the illustration.

      HINT: 

      When the system is functioning normally, one wheel revolution generates 4 pulses. As the vehicle speed increases, the width indicated by (A) in the illustration narrows.

NG → See step   5 

OK: Go to next step 

1. Disconnect the D55 navigation receiver assembly connector.
2. Disconnect the D18 combination meter assembly connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   D55-3 (SPD) - D18-10 (+S)	Always	Below 1 Ω
   D55-3 (SPD) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   6