Inspection Procedure

WARNING: This page is about a different car, the 2002 Toyota Sequoia. However, it is still accessible from the selected car via links, so may be relevant.

Check Booster Pedal Force Switch.
Preparation in case of using the oscilloscope :
1. Connect the oscilloscope to the between terminals PSNO(1) and STS(5), PSNC(2) and STS(5) of the brake booster with connector still connected.
  
  Fig 1: Identifying Test Terminals PSNO(1), STS(5), PSNC(2) & STS(5) For Oscilloscope
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Turn the ignition switch ON.
  Check : The signal waveform in the case where the brake pedal is depressed and released.
  
  OK : See Fig 2 for more information or specifications.
  
  Fig 2: Depressing & Releasing Brake Pedal Waveform
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Preparation in case of not using the oscilloscope :
1. Disconnect the connector from the brake booster.
2. Turn the ignition switch ON.
Check : Continuity between the terminals in case where the brake pedal is depressed and released.
1. OK : Refer to Fig 3 for more information.
  
  Fig 3: Testing PSNO(1), STS(5), PSNC(2) & STS(5) Continuity
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Fig 4: Brake Pedal Continuity Chart
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. NG : Replace brake booster.
  OK : Go to step 2.
Check For Open And Short Circuit In Harness And Connector Between Booster Pedal Switch And Skid Control ECU. See HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE .
1. NG : Repair or replace harness or connector.
2. OK : Check and replace skid control ECU.