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Inspection Procedure

  1. DRIVING TEST 
    1. Start the engine.
    2. Turn the ECT SNOW switch "OFF" (Normal drive mode).
    3. Confirm vehicle response by driving from a parked position to fully depressing the accelerator pedal.
    4. Turn the ECT SNOW switch "ON" and perform the same check as above.

      Confirm that there is a difference between ECT SNOW switch "ON" and "OFF".

      HINT:

      • Driving test should be done on a paved road (a nonskid road).
      • Make sure not to use the TRAC system when testing a vehicle equipped with one.

        OK: 

        There is a difference in acceleration between "ON" and "OFF". 

    NG: Go to step 2 

    OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOM TABLE 

  2. CHECK HARNESS AND CONNECTOR (PATTERN SELECT SWITCH ASSEMBLY - BODY GROUND) 
    1. Disconnect the connector of pattern select switch.
    2. Measure the resistance according to the value(s) in the table below.

      Standard resistance 

      HARNESS AND CONNECTOR (PATTERN SELECT SWITCH ASSEMBLY - BODY GROUND) STANDARD RESISTANCE SPECIFICATIONS

      Tester Connection Specified Condition
      3 - Body ground Below 1 Ω
      Fig 1: Identifying Pattern Select Switch Assembly
      G05316913Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  3. INSPECT PATTERN SELECT SWITCH ASSEMBLY 
    1. Measure the resistance according to the value(s) in the table below.

      Standard resistance 

      PATTERN SELECT SWITCH ASSEMBLY STANDARD RESISTANCE SPECIFICATIONS

      Switch Condition Tester Connection Specified Condition
      Press continuously Pattern select switch (SNOW) 1 - 3 Below 1 Ω
      Release Pattern select switch (SNOW) 10 kΩ or higher
      Fig 2: Identifying Pattern Select Switch Assembly
      G05316914Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPLACE PATTERN SELECT SWITCH ASSEMBLY 

    OK: Go to next step 

  4. CHECK HARNESS AND CONNECTOR (PATTERN SELECT SWITCH ASSEMBLY - MAIN BODY ECU) 
    1. Connect the connector of pattern select switch.
    2. Disconnect the cowl side junction block (main body ECU RH) connector.
    3. Measure the resistance between terminal SNOW of the cowl side junction block (main body ECU RH) and body ground.

      Standard resistance 

      HARNESS AND CONNECTOR (PATTERN SELECT SWITCH ASSEMBLY - MAIN BODY ECU) STANDARD RESISTANCE SPECIFICATIONS

      Switch Condition Tester Connection Specified Condition
      Press continuously Pattern select switch (SNOW) J75-17 (SNOW) - Body ground Below 1 Ω
      Release Pattern select switch (SNOW) 10 kΩ or higher
      Fig 3: Identifying Cowl Side Junction Block (Main Body ECU RH) Connector
      G05316915Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOM TABLE