Pattern Select Switch Snow Mode Circuit: Wiring Diagram

Fig 1: Wiring Diagram - Pattern Select Switch Snow Mode Circuit

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HINT:

(*) Pattern Select Switch (ECT SNOW Switch)

When the ECT SNOW switch is pushed, the switch contact is made and the ECT SNOW mode is selected.

To cancel the ECT SNOW mode, push the ECT SNOW switch once again.

The ECT SNOW mode is automatically cancelled out when the engine switch is turned "OFF".

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 SYMPTOMS 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.

      Resistance 

      PATTERN SELECT SWITCH ASSEMBLY - BODY GROUND RESISTANCE
      
      

      Tester Connection	Specified Condition
      3 - Body ground	Below 1 Ω

   NG : REPAIR OR REPLACE HARNESS OR CONNECTOR 

   Fig 2: Identifying Terminals Of Pattern Select Switch Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   OK : Go to next step 

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

      Resistance 

      PATTERN SELECT SWITCH ASSEMBLY RESISTANCE
      
      

      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

   NG : REPLACE PATTERN SELECT SWITCH ASSEMBLY 

   Fig 3: Identifying Terminals Of Pattern Select Switch Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   OK : Go to next step 

4. CHECK HARNESS AND CONNECTOR 
   1. Connect the connector of pattern select switch.
   2. Disconnect the cowl side junction block (multiplex network body ECU) connector.
   3. Measure the resistance between terminal PWR of the cowl side junction block (multiplex network body ECU) and body ground.

      Resistance 

      MULTIPLEX NETWORK BODY ECU CONNECTOR AND GROUND RESISTANCE
      
      

      Switch Condition	Tester Connection	Specified Condition
      Press continuously Pattern select switch (SNOW)	K68 - 17 (SNOW) - Body ground	Below 1 Ω
      Release Pattern select switch (SNOW)		10 kΩ or higher

   NG : REPAIR OR REPLACE HARNESS OR CONNECTOR 

   Fig 4: Identifying Cowl Side Junction Block (Multiplex Network Body ECU) Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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