Vehicle Speed Signal Circuit between Radio Receiver and Combination Meter [10/2016 - 10/2017]: Procedure

1. Enter the "Vehicle Signal Check Mode" screen. Refer to Check Vehicle Signal in Operation Check.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Refer to OPERATION CHECK [10/2016 - 09/2020]

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 [10/2016 - 09/2020]

   Result

   Proceed to
   OK
   NG

Result: 

OK 

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE. Refer to  PROBLEM SYMPTOMS TABLE [10/2016 - 09/2020] 

Result: 

NG 

See step  2

1. Check the output waveform.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a

   Component with harness connected (Combination Meter Assembly)

   -

   -

   1. Remove the combination meter assembly with the connector still connected.
   2. Connect an oscilloscope to terminal K3-19 (+S) and body ground.
   3. Turn the engine switch on (IG).
   4. Turn a wheel slowly.
   5. Check the signal waveform according to the condition(s) in the table below.

      Item	Condition
      Measurement terminal	K3-19 (+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.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

GO TO METER / GAUGE SYSTEM. Refer to  Speed Signal Circuit [10/2016 - 10/2017] 

Result: 

OK 

See step  3

1. Check the input waveform.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a

   Component with harness connected (Radio Receiver Assembly)

   -

   -

   1. Remove the radio receiver assembly with the connector still connected.
   2. Connect an oscilloscope to terminal K72-17 (SPD) and body ground.
   3. Turn the engine switch on (IG).
   4. Turn a wheel slowly.
   5. Check the signal waveform according to the condition(s) in the table below.

      Item	Condition
      Measurement terminal	K72-17 (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.

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE RADIO RECEIVER ASSEMBLY. Refer to  REMOVAL [04/2013 - 09/2020] 

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR (RADIO RECEIVER ASSEMBLY - COMBINATION METER ASSEMBLY)