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Inspection Procedure

NOTE: When replacing the skid control ECU, perform zero point calibration and store system information (See CALIBRATION  ).
  1. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - BRAKE ACTUATOR) 
    1. Make sure that there is no looseness at the locking part and the connecting part of the connectors.
    2. Disconnect the skid control ECU connector and the brake actuator connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance 

      STANDARD RESISTANCE

      Tester Connection Condition Specified Condition
      A35-14 (SSEL) - A13-44 (SSEL) Always Below 1 Ω
      A35-14 (SSEL) - Body ground Always 10 kΩ or higher
      A35-16 (SEL2) - A13-41 (SEL2) Always Below 1 Ω
      A35-16 (SEL2) - Body ground Always 10 kΩ or higher
    4. Fig 1: Identifying Harness And Connector (Skid Control ECU - Brake Actuator)
      G05752638Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  2. INSPECT SKID CONTROL ECU (IDENTIFICATION OUTPUT) 
    1. Reconnect the skid control ECU connector and the brake actuator connector
    2. Start the engine
    3. Measure the voltage according to the value(s) in the table below

      Standard Voltage 

      STANDARD VOLTAGE

      Tester Connection Condition Specified Condition
      A35-14 (SSEL) - Body ground Low (Normal) 0 V
      A35-14 (SSEL) - Body ground Middle 3.7 to 8.26 V
      A35-14 (SSEL) - Body ground High 7.8 to 14 V
      A35-16 (SEL2) - Body ground Low (Normal) 0 V
      A35-16 (SEL2) - Body ground Middle 3.7 to 8 26 V
      A35-16 (SEL2) - Body ground High 7 8 to 14 V
      Fig 2: Identifying Skid Control ECU (Identification Output)
      G05752639Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      OK: Input voltage of SSEL and SEL2 is the same under all conditions. 

    NG: REPLACE BRAKE ACTUATOR ASSEMBLY  (See REMOVAL  )

    OK: Go to next step 

  3. RECONFIRM DTC 
    1. Turn the engine switch off.
    2. Clear the DTCs (See DTC CHECK / CLEAR  )
    3. Drive the vehicle at a speed of 24 km/h (15 mph) or more
    4. Check if the same DTC is recorded (See DTC CHECK / CLEAR  )

      Result 

      RESULT REFERENCE

      Result Proceed to
      DTC (C1305/21) is not output A
      DTC (C1305/21) is output B

      HINT

      • If a speed signal of 6 km/h (4 mph) or more is input to the skid control ECU with the engine switch on (IG) and the stop light switch off, the ECU performs self diagnosis of the motor and solenoid circuits
      • If the normal system code is output (no trouble codes are output), slightly jiggle the connectors, wire harness, and fuses of the skid control ECU and/or brake actuator assembly. Make sure that no DTCs are output
      • If any DTCs are output while jiggling a connector or wire harness of the skid control ECU and/or brake actuator assembly, inspect and repair the connector or wire harness.
      • It is suspected that the DTCs were output due to a bad connection of the connector terminal.

    B: REPLACE SKID CONTROL ECU  (See REMOVAL  )

    A: CHECK FOR INTERMITTENT PROBLEMS (SYMPTOM SIMULATION)  (See DIAGNOSIS SYSTEM  )