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Wiper Signal Circuit: Procedure

  1. INSPECT DRIVING SUPPORT ECU ASSEMBLY 
    1. Disconnect the driving support ECU assembly connector.
      Fig 1: Identifying L151 Connector Terminals
      GTY329181Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Turn the power switch on (IG).
    3. Set the windshield wiper switch assembly to the HI position.
    4. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      L151-32 (WIP2) - Body ground Power switch on (IG), windshield wiper switch assembly Hi position 11 to 14 V
      TEXT IN ILLUSTRATION

      *a Front view of wire harness connector
      (to Driving Support ECU assembly)

    NG → See step   3 

    OK → See step   2 

  2. PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE. Refer to  PROBLEM SYMPTOMS TABLE 
  3. CHECK HARNESS AND CONNECTOR (DRIVING SUPPORT ECU ASSEMBLY - WINDSHIELD WIPER SWITCH) 
    1. Disconnect the windshield wiper switch assembly connector.
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance (Check for Open)

      Tester Connection Condition Specified Condition
      L151-32 (WIP2) - L48-4 (+2) Always Below 1 Ω

      Standard Resistance (Check for Short)

      Tester Connection Condition Specified Condition
      L151-32 (WIP2) or L48-4 (+2) - Body ground Always 10 kΩ or higher

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (DRIVING SUPPORT CONTROL ECU - WINDSHIELD WIPER SWITCH) 

    OK → See step   4 

  4. GO TO WIPER AND WASHER SYSTEM. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING