Headlight Signal Circuit [08/2015 - 08/2019]: Procedure

1. Remove the main body ECU (multiplex network body ECU) with the connector(s) still connected (Refer to REMOVAL [08/2015 - 08/2019] ).

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

   Standard Voltage

   Tester Connection	Switch Condition	Specified Condition
   G46-16 (HDLO) - Body ground	Headlight dimmer switch in head	Below 1 V
   G46-16 (HDLO) - Body ground	Headlight dimmer switch not in head	11 to 14 V

   TEXT IN ILLUSTRATION
   
   

   *a	Component with harness connected (Main Body ECU [Multiplex Network Body ECU])

Result: 

OK 

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE 

(Refer to PROBLEM SYMPTOMS TABLE [08/2015 - 08/2019] )

Result: 

NG 

See step  2

1. Disconnect the G46 main body ECU (multiplex network body ECU) connector.
2. Disconnect the A32 headlight cleaner control relay connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   G46-16 (HDLO) - A32-1 (HDLO)	Always	Below 1 Ω
   G46-16 (HDLO) or A32-1 (HDLO) - Body ground	Always	10 kΩ or higher

Result: 

OK 

REPLACE HEADLIGHT CLEANER CONTROL RELAY 

(Refer to REMOVAL [08/2015 - ] )

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR