Inspection Procedure

WARNING: This page is about a different car, the 2004 Lexus LS 430. However, it is still accessible from the selected car via links, so may be relevant.

PERFORM ACTIVE TEST BY HAND-HELD TESTER
1. Operate the hand-held tester according to the steps on the display and select the "ACTIVE TEST".
  METER:
  
  Fig 1: Meter - Active Test Chart
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
OK:

Needle indication is normal.

NG: REPLACE COMBINATION METER ASSY (SEE OVERHAUL )

OK: Go to next step.
READ VALUE OF HAND-HELD TESTER (VEHICLE SPEED SIGNAL)
1. Operate the hand-held tester according to the steps on the display and select the "DATA LIST".
  METER:
  
  Fig 2: Meter - Data List
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
OK:

Vehicle speed displayed on the tester is almost the same as the actual vehicle speed.

NG: Go to step 3

OK: REPLACE COMBINATION METER ASSY (SEE OVERHAUL )
READ VALUE OF HAND-HELD TESTER (VEHICLE SPEED SIGNAL)
1. Operate the hand-held tester according to the steps on the display and select the "DATA LIST"
  ABS:
  
  Fig 3: ABS - Data List
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
OK:

Vehicle speed displayed on the tester is almost the same as the actual vehicle speed.

NG: GO TO BRAKE CONTROL SYSTEM (see HOW TO PROCEED WITH TROUBLESHOOTING )

OK: Go to next step.
INSPECT COMBINATION METER ASSY
INSPECTION USING OSCILLOSCOPE
1. Check the input signal waveform.
  1. Remove the combination meter assy.
  2. Connect the oscilloscope to the terminals C12-18 and body ground.
  3. Start the engine.
    
    Fig 4: Inspecting Combination Meter Assy
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  4. Check the signal waveform according to the condition (s) in the figure Fig 5 below.
    
    Fig 5: Item Condition Chart
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    
    Fig 6: Identifying Signal Waveform
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    
    OK: Go to next step.
    
    As shown in the illustration
  HINT:
  
  As vehicle speed increases, the cycle of the signal waveform narrows.
  
  NG: Go to step 5
  
  OK: REPLACE COMBINATION METER ASSY (SEE OVERHAUL )
2. CHECK HARNESS AND CONNECTOR (ABS & TRACTION ACTUATOR ASSY (VSC) - COMBINATION METER ASSY) (SEE ELECTRONIC CIRCUIT INSPECTION PROCEDURE )
  1. Disconnect the C12 and S42 connectors.
  2. Measure the resistance according to the value (s) in the figure Fig 7 below.
  Standard:
  
  Fig 7: Terminals Resistance Reference Chart
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Fig 8: Checking Harness And Connector (ABS & Traction Actuator Assy (VSC) - Combination Meter Assy)
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
NG: REPAIR OR REPLACE HARNESS AND CONNECTOR

OK: Go to next step.
INSPECT ABS & TRACTION ACTUATOR ASSY (VSC)
1. Disconnect the S42 connector.
2. Measure the voltage according to the value (s) in the figure Fig 9 below.
Standard:

Fig 9: Terminals Voltage Reference Chart
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPLACE COMBINATION METER ASSY (SEE OVERHAUL )

OK: GO TO BRAKE CONTROL SYSTEM (see HOW TO PROCEED WITH TROUBLESHOOTING )

Fig 10: Inspecting ABS & Traction Actuator Assy (VSC)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002