Vehicle Speed Signal Circuit between Radio Receiver and Combination Meter [08/2015 - ]: Procedure

1. Enter the "Vehicle Signal Check Mode" screen. Refer to Check Vehicle Signal in Operation Check. Refer to OPERATION CHECK [08/2015 - ] .

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

2. While driving the vehicle, compare the value displayed for "SPEED" 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 Signal Check Mode" screen is almost the same as the actual vehicle speed measured using the Techstream. Refer to DATA LIST / ACTIVE TEST [08/2015 - ] .

NG → See step   2 

OK → See step   8 

1. Check the output waveform.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   1. Remove the combination meter assembly with the connector still connected.
   2. Connect an oscilloscope to terminal I18-3 (+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	I18-3 (+S) - Body ground
      Tool setting	5 V/DIV., 20 ms./DIV.
      Vehicle condition	Wheel being rotated

      OK

      The waveform is similar to that 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.

      TEXT IN ILLUSTRATION
      
      

      *a	Component with harness connected (Combination Meter Assembly)

NG → See step   7 

OK: Go to next step 

1. Check the input waveform.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   1. Remove the radio and display receiver assembly with the connector still connected.
   2. Connect an oscilloscope to terminal I67-17 (SPD) 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	I67-17 (SPD) - Body ground
      Tool setting	5 V/DIV., 20 ms./DIV.
      Vehicle condition	Wheel being rotated

      OK

      The waveform is similar to that 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.

      TEXT IN ILLUSTRATION
      
      

      *a	Component with harness connected (Radio and Display Receiver Assembly)

NG → See step   4 

OK → See step   6 

1. Disconnect the I67 radio and display receiver assembly connector.
2. Disconnect the I124 junction connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   I67-17 (SPD) - I124-17	Always	Below 1 Ω

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Disconnect the I18 combination meter assembly connector.
2. Disconnect the I124 junction connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   I18-3 (+S) - I124-18	Always	Below 1 Ω

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → REPAIR OR REPLACE HARNESS OR CONNECTOR (JUNCTION CONNECTOR)