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Speed Sensor Diagnosis System

NOTE: While checking the speed sensor diagnosis system, the Rear Anti-Lock Brake System does not work and brake system works as a normal brake system. If it is a 4WD model, set the vehicle in 2WD condition.
  1. Inspect that the battery voltage is about 12 volts.
  2. Turn the ignition switch to ON.
  3. Check that the "REAR ANTI-LOCK" warning light turns on for about 2 seconds. See Figure. If not, inspect and repair or replace the fuse, bulb and wiring harness.
  4. Check that the "REAR ANTI-LOCK" warning light turns off.
  5. Turn the ignition switch to OFF.
    6. NOTE: Check connector is located in the right side of the engine compartment, attached to the fuse/relay box.
  6. Connect the terminal Tc to E1 of the check connector. Connect the terminal Ts to E1 of the check connector. See Figure.
  7. Pull the parking brake lever all the way. This will turn the parking brake switch on.
    8. NOTE: If the engine is stated with depressing the brake pedal, this inspection changes to inspection of DECELERATION SENSOR OPERATION DIAGNOSIS SYSTEM .
    Fig 1: Normal Speed Sensor Diagnosis Light Flashes
    G00178326Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  8. Start the engine without depressing the brake pedal. Check that the warning light blinks about 4 times per second. See .
    9. NOTE: If transfer case is in 4WD mode, the warning light will show a trouble code 88.
  9. If the warning light shows the diagnostic codes, inspect and repair or replace the trouble parts. See DIAGNOSTIC TROUBLE CODE DEFINITIONS . Then, clear the diagnostic codes and inspect this diagnosis system again.
  10. If the warning light does not blink, inspect the parking brake switch, check connector, speed sensor installation and ECU.
  11. Release the parking brake lever and drive the vehicle straight ahead at low speed.
  12. Check that the warning light turns OFF while the vehicle speed is 4-6 km/h (2.5-3.7 MPH). See Fig 2. If the warning light does not turn OFF, inspect the speed sensor installation. If the speed sensor installation is OK, replace the speed sensor. If the warning light turns off while the vehicle speed is 4-6 km/h (2.5-3.7 MPH), the check is completed. When the vehicle speed is not within specified speed range, the warning light will blink again. In this condition, speed sensor is OK.
    Fig 2: Warning Light Operation During Low Speed Test Drive
    G00178327Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    13. NOTE: While the warning light is off, do not give any shocks to vehicle such as acceleration, deceleration, braking, shift change, steering or shocks from the road condition.
    Fig 3: Warning Light Operation During 25-31 MPH TestDrive
    G00178328Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  13. Drive the vehicle straight ahead at about 40-50 km/h (24.9-31.1 MPH), and check that the warning light turns on after a 1 second pause. See Fig 3. If the warning light turns on without blinking when the vehicle speed is not within the specified speed range above, stop the vehicle and read the diagnostic code. See DIAGNOSTIC TROUBLE CODE DEFINITIONS . Repair the malfunctioning part.If the warning light turns on while vehicle speed is about 40-50 km/h (24.9-31.1 MPH), the check is complete. When vehicle speed is not within specified range, the warning light will blink again. In this condition, sensor rotor is okay.
  14. Stop the vehicle and turn the ignition switch to OFF.
  15. Disconnect the terminals Tc and Ts from the terminal E1 of the check connector.
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