DTC B15C2: Speed Signal Malfunction: Procedure

1. Enter the "GPS & Vehicle Sensor" (Vehicle Sensors). Refer to OPERATION CHECK .
   Fig 1: Screen Display - GPS & Vehicle Sensor

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

   OK

   The readings are equal or almost equal.

NG → See step   4 

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: Go to next step 

1. Remove the combination meter assembly with the connector(s) still connected.
   Fig 2: Inspecting Combination Meter Assembly (Speed Signal) With Input Waveform

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Connect an oscilloscope to terminal D18-10 (+S) and body ground.
3. Turn the ignition switch to ON.
4. Check the signal waveform according to the condition(s) in the table below.
   MEASUREMENT CONDITION
   
   

   Item	Condition
   Terminal No. (Symbol)	D18-10 (+S) - Body ground
   Tool setting	5 V/DIV., 20 ms./DIV.
   Condition	Vehicle being driven at approx, 20 km/h (12 mph)

   OK

   The waveform display is as shown in the illustration.

   HINT: 

   When the system is function normally, one wheel revolution generates 4 pulses.

   As the vehicle speed increases, the width indicated by (A) in the illustration narrows.

   TEXT IN ILLUSTRATION
   
   

   *1	Component with harness connected (Combination Meter Assembly)

NG → See step   6 

OK → See step   5