Automatic High Beam Switch Indicator does not Come ON [08/2020 - 12/2021]: Procedure

1. Connect the Techstream to the DLC3.
2. Turn the ignition switch to ON.
3. Turn the Techstream on.
4. Enter the following menus: Body Electrical / Main Body / Active Test.
5. Perform the Active Test according to the display on the Techstream.

   Body Electrical > Main Body > Active Test 

   Tester Display	Measurement Item	Control Range	Diagnostic Note
   Automatic High Beam Switch Light	Auto high beam switch indicator light	OFF or ON	-

   Body Electrical > Main Body > Active Test 

   Tester Display
   Automatic High Beam Switch Light

   OK

   Auto high beam switch indicator light illuminates.

   Result

   Proceed to
   OK
   NG

Result: 

OK 

USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [11/2018 - ] 

Result: 

NG 

See step  2

1. Remove the auto high beam switch.

   Refer to REMOVAL [11/2018 - ]

2. Inspect the auto high beam switch.

   Refer to INSPECTION [11/2018 - ]

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPLACE AUTO HIGH BEAM SWITCH. Refer to  REMOVAL [11/2018 - ] 

Result: 

OK 

See step  3

1. Disconnect the auto high beam switch connector.
2. Measure the voltage according to the value (s) in the table below.

   Standard Voltage

   Tester Connection	Switch Condition	Specified Condition
   G42-3 (IND) - Body ground	Ignition switch off	11 to 14 V

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Front view of wire harness connector (to Auto High Beam Switch)

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  4

1. Disconnect the G42 auto high beam switch connector.
2. Disconnect the G45 main body ECU (multiplex network body ECU) connector.
3. Measure the resistance according to the value (s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   G42-4 (AZBI) - G45-21 (AHID)	Always	Below 1 Ω
   G42-4 (AZBI) or G45-21 (AHID) - Body ground	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU). Refer to  REMOVAL [08/2020 - 12/2021] 

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR