DTC B15C2: Speed Signal Malfunction [12/2019 - 10/2022]: Procedure

1. Clear the DTCs.

   Body Electrical > Navigation System > Clear DTCs 

2. Recheck for DTCs and check that no DTCs are output.

   Body Electrical > Navigation System > Trouble Codes 

   OK

   No DTCs are output.

   Result

   Proceed to
   OK
   NG

Result: 

OK 

USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [12/2019 - ] 

Result: 

NG 

See step  2

1. Enter the "System Sensors Check" screen. Refer to Check GPS & Vehicle Sensors in Operation Check.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Refer to OPERATION CHECK [12/2019 - 10/2022]

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 procedure inspection referring to values in 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 GTS.

   for HV Model: Refer to DATA LIST / ACTIVE TEST [12/2019 - 11/2023]

   for Gasoline Model: Refer to DATA LIST / ACTIVE TEST [12/2019 - 11/2023]

   Result

   Proceed to
   OK
   NG

Result: 

OK 

See step  5

Result: 

NG 

See step  3

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(s) still connected.
   2. Connect an oscilloscope to terminal H21-6 (+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	H21-6 (+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  HOW TO PROCEED WITH TROUBLESHOOTING [12/2019 - ] 

Result: 

OK 

See step  4

1. Disconnect the H18 navigation ECU connector.
2. Disconnect the H21 combination meter assembly connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   H18-9 (SPD) - H21-6 (+S)	Always	Below 1 Ω
   H18-9 (SPD) or H21-6 (+S) - Body ground	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  5

1. Replace the navigation ECU with a new or known good one.

   Refer to REMOVAL [12/2019 - 10/2022]

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  6

1. Clear the DTCs.

   Body Electrical > Navigation System > Clear DTCs 

2. Recheck for DTCs and check that no DTCs are output.

   Body Electrical > Navigation System > Trouble Codes 

   OK

   No DTCs are output.

   Result

   Proceed to
   OK
   NG

Result: 

OK 

END (NAVIGATION ECU IS DEFECTIVE) 

Result: 

NG 

REPLACE RADIO RECEIVER ASSEMBLY. Refer to  REMOVAL [12/2019 - 10/2022]