Inspection Procedure

HINT:

Start the inspection from step 1 when using the hand-held tester and start from step  2 when not using the hand-held tester.

1. READ VALUE OF HAND-HELD TESTER 
   1. Operate the hand-held tester and select the DATA LIST.

      Skid control ECU with actuator: 

      TERMINAL WIRING SPECIFICATION
      
      

      Item	Measurement Item/ Range (Display)	Normal Condition	Diagnostic Note
      WHEELSPD FR	Vehicle speed /Min.: 0 km/h (0 mph), Max.: 326 km/h (202 mph)	Almost equal to actual speed (When driving)	-
      WHEEL SPDFL	Vehicle speed /Min.: 0 km/h (0 mph), Max.: 326 km/h (202 mph)	Almost equal to actual speed (When driving)	-
      WHEELSPD RR	Vehicle speed/ Min.: 0 km/h (0 mph), Max.: 326 km/h (202 mph)	Almost equal to actual speed (When driving)	-
      WHEELSPD RL	Vehicle speed /Min.: 0 km/h (0 mph), Max.: 326 km/h (202 mph)	Almost equal to actual speed (When driving)	-

   OK : Vehicle speed displayed on tester is almost equal to the actual vehicle speed. 

   1. NG : Go to BRAKE SYSTEM (See  HOW TO PROCEED WITH TROUBLESHOOTING  OR  HOW TO PROCEED WITH TROUBLESHOOTING  ) 
   2. OK : GO TO NEXT STEP. 
2. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU WITH ACTUATOR - COMBINATION METER ASSY) 
   1. Disconnect the C10 and S1 connectors.
   2. Measure the resistance between the terminals.

      Standard: 

      SKID CONTROL ECU WITH ACTUATOR - COMBINATION METER ASSY
      
      

      Tester Connection	Specified Condition
      C10-10 - S1-12*1	Below 1 Ω
      C10-10 - S1-26*2	Below 1 Ω
      C10-10 - Body ground	10 kΩ or higher

      Fig 1: Checking Harness And Connector (Skid Control ECU With Actuator - Combination Meter Assy)

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   1. NG : REPAIR OR REPLACE HARNESS OR CONNECTOR 
   2. OK : GO TO NEXT STEP. 
3. INSPECT SKID CONTROL ECU WITH ACTUATOR 
   1. Disconnect the S1 connector.
   2. Measure the voltage between the terminal and body ground.

      Standard: 

      TERMINAL WIRING SPECIFICATION
      
      

      Tester Connection	Condition	Specified Condition
      S1-12*1 - Body ground	Ignition switch ON	10 to 14 V
      S1 -26*2 - Body ground	Ignition switch ON	10 to 14 V

      Fig 2: Inspecting Skid Control ECU With Actuator

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   1. NG : REPLACE COMBINATION METER ASSY (See  INSTRUMENT PANEL/METER  ) 
   2. OK : GO TO NEXT STEP. 
4. INSPECT COMBINATION METER ASSY 

   INSPECTION USING OSCILLOSCOPE 

   1. Check the input signal waveform.
      1. Remove the combination meter but do not disconnect the connectors.
      2. Connect the oscilloscope to terminal C10-10 and body ground.
         Fig 3: Connecting Oscilloscope To C10-10 And Body Ground

         Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      3. Start the engine.
      4. Check the signal waveform according to COMBINATION METER  .
         COMBINATION METER
         
         

         Item	Condition
         Tool setting	5V/DIV.,20 msec./DIV.
         Vehicle condition	Driving at approx. 20 km/h (12.4 mph)

         Fig 4: Checking Signal Waveform

         Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

         OK : As shown in  Fig 4  . 

         HINT:

         As the vehicle speed increases, wavelength shortens

   1. NG : Go to BRAKE SYSTEM (See  HOW TO PROCEED WITH TROUBLESHOOTING  OR  HOW TO PROCEED WITH TROUBLESHOOTING  ) 
   2. OK : REPLACE COMBINATION METER ASSY (See  INSTRUMENT PANEL/METER  )