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 ignition 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 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 

   TESTER CONNECTION SPECIFIED CONDITION CHART
   
   

   Tester Connection	Specified Condition
   3 - Body ground	Below 1 Ω

   Fig 2: Checking Pattern Select Switch Assembly

   Courtesy 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 

   TESTER CONNECTION SPECIFIED CONDITION CHART
   
   

   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 3: Inspecting Pattern Select Switch Assembly

   Courtesy 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 

   TESTER CONNECTION SPECIFIED CONDITION CHART
   
   

   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 4: Identifying Cowl Side Junction Block (Main Body ECU RH) Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   NG : REPAIR OR REPLACE HARNESS OR CONNECTOR 

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