DTC C1776/76: Speed Sensor Circuit; DTC C1784/84: Right Rear Speed Sensor Circuit; DTC C1785/85: Left Rear Speed Sensor Circuit: Procedure

1. Connect the Techstream to the DLC3.
2. Turn the ignition switch to the ON position, and push the Techstream main switch on.
3. Select the item below in the DATA LIST, and read its value displayed on the Techstream.

   Air suspension

   Item	Normal Condition
   RR Wheel Speed	Actual right rear wheel speed
   RL Wheel Speed	Actual left rear wheel speed

4. Check that there is no difference between the speed value output from the speed sensor displayed on the Techstream and the speed value displayed on the speedometer when driving the vehicle.

   OK

   There is almost no difference in the displayed speed values.

   HINT: 

   There is tolerance of +- 10 % in the speedometer indication.

NG → Go to next step 

OK → REPLACE SUSPENSION CONTROL ECU 

1. Check if the normal code is output by VSC system. Refer to DTC CHECK / CLEAR .

   OK

   No DTC output from VSC system.

NG → REPAIR DTC OUTPUT 

OK: Go to next step 

1. Disconnect the suspension control ECU S16 connector.
   Fig 1: Identifying Suspension Control ECU S16 Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Disconnect the brake actuator assembly S1 connector.
3. Measure the resistance according to the values in the table below.

   Standard resistance

   Tester Connection	Specified Condition
   S16-8 (FLO) - S1-40 (RLO)	Below 1 Ω
   S16-9 (FRO) - S1-39 (RRO)	Below 1 Ω
   S16-8 (FLO) - Body ground	10 kΩ or higher
   S16-9 (FRO) - Body ground	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Connect the suspension control ECU S16 connector.
   Fig 2: Identifying Suspension Control ECU S16 Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Remove the suspension control ECU with connector being connected.
3. Connect the brake actuator assembly S1 connector.
4. Turn the ignition switch to the ON position.
5. Check output waveform.
   1. Using an oscilloscope, connect the terminals, as shown in the chart.

      Measure Point	Tester Connection
      Rear RH	S16-9 (FRO) - S16-1 (GND)
      Rear LH	S16-8 (FLO) - S16-1 (GND)

   2. Drive the vehicle at about 20 km/h (12 mph), and check the output waveform.
      Fig 3: Identifying Normal Signal Waveform

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      OK

      The output waveform appears as shown in the illustration above.

      Item	Contents
      Tool setting	5 V/DIV., 5 ms./DIV.
      Vehicle condition	When drive the vehicle at about 20 km/h 12 (mph)

      HINT: 

      As the vehicle speed becomes higher, the waveform cycle gets shorter.

NG → REPLACE BRAKE ACTUATOR ASSEMBLY 

OK → REPLACE SUSPENSION CONTROL ECU