Headlight Cleaner Switch Circuit: Procedure

1. Disconnect the A3 headlight cleaner control relay connector.
   Fig 1: Identifying A3 Headlight Cleaner Control Relay Connector Terminal

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2. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Switch Condition	Specified Condition
   A3-2 (H) - Body ground	Light control switch in HEAD and headlight cleaner switch ON	11 to 14 V
   A3-2 (H) - Body ground	Headlight cleaner switch OFF	Below 1 V

NG → See step   4 

OK: Go to next step 

1. Measure the voltage according to the value(s) in the table below.
   Fig 2: Identifying A3 Headlight Cleaner Control Relay Connector Terminal

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard Voltage

   Tester Connection	Switch Condition	Specified Condition
   A3-5 (FRWA) - Body ground	Engine switch on (IG) and front washer switch OFF	11 to 14 V
   A3-5 (FRWA) - Body ground	Engine switch on (IG) and front washer switch ON	Below 1 V

NG → See step   5 

OK: Go to next step 

1. Measure the voltage according to the value(s) in the table below.
   Fig 3: Identifying A3 Connector Terminal

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard Voltage

   Tester Connection	Switch Condition	Specified Condition
   A3-1 (HDLO) - Body ground	Light control switch off	11 to 14 V
   A3-1 (HDLO) - Body ground	Light control switch in HEAD	Below 1 V

NG → See step   6 

OK → See step   7 

1. Remove the headlight cleaner switch assembly. Refer to COMPONENTS .
   Fig 4: Identifying Headlight Cleaner Switch Assembly Connector Terminal

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Switch Condition	Specified Condition
   4 - 3	Headlight cleaner switch OFF	10 kΩ or higher
   4 - 3	Headlight cleaner switch ON	Below 1 Ω

NG → See step   8 

OK → REPAIR OR REPLACE HARNESS OR CONNECTOR (HEAD LP RELAY - HEADLIGHT CLEANER CONTROL RELAY) 

1. Disconnect the 2F front controller connector.
   Fig 5: Identifying 2F Front Controller Connector Terminal

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2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   A3-5 (FRWA) - 2F-8	Always	Below 1 Ω
   A3-5 (FRWA) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → REPLACE FRONT CONTROLLER (MULTIPLEX NETWORK BODY ECU) 

1. Disconnect the A36 main body ECU RH (cowl side junction block RH) connector.
   Fig 6: Identifying A36 Main Body ECU RH Connector Terminal

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connector	Condition	Specified Condition
   A3-1 (HDLO) - A36-4 (HDLO)	Always	Below 1 Ω
   A3-1 (HDLO) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → REPAIR OR REPLACE MAIN BODY ECU RH (COWL SIDE JUNCTION BLOCK RH)