DTC B15C2: Speed Signal Malfunction [10/2014 - 10/2015]: Procedure

1. Enter the "System Sensors Check" screen.

   Refer to Check System Sensors in Operation Check (Refer to OPERATION CHECK [10/2014 - ] ).

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

2. While driving the vehicle, compare the value of "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 "System Sensors Check" screen is almost the same as the actual vehicle speed measured using the Techstream (Refer to DATA LIST / ACTIVE TEST [10/2014 - 10/2015] ).

Result: 

OK 

REPLACE NAVIGATION ECU SUB-ASSEMBLY 

(Refer to REMOVAL [10/2014 - ] )

Result: 

NG 

See step  2

1. Check the output waveform.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   1. Remove the combination meter assembly with the connector(s) still connected.
   2. Connect an oscilloscope to terminal I18-9 (+S) and body ground.
   3. Turn the power 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	I18-9 (+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)

Result: 

NG 

GO TO METER / GAUGE SYSTEM 

(Refer to Speed Signal Circuit [10/2014 - 10/2015] )

Result: 

OK 

See step  3

1. Check the input waveform.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   1. Remove the navigation ECU sub-assembly with the connector(s) still connected.
   2. Connect an oscilloscope to terminal I8-17 (SPD) and body ground.
   3. Turn the power 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	I8-17 (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 (Navigation ECU Sub-assembly)

Result: 

OK 

REPLACE NAVIGATION ECU SUB-ASSEMBLY 

(Refer to REMOVAL [10/2014 - ] )

Result: 

NG 

See step  4

1. Disconnect the I8 navigation ECU sub-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
   I8-17 (SPD) - I124-17	Always	Below 1 Ω

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  5

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
   I18-9 (+S) - I124-18	Always	Below 1 Ω

Result: 

OK 

REPLACE JUNCTION CONNECTOR 

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR