Headlight Signal Circuit: Procedure

1. Disconnect the A43 headlight cleaner control relay connector.
2. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   A43-1 (HDLO) - Body ground	Light control switch in head position	Below 1 V
   	Light control switch off	11 to 14 V

NG → See step   2 

OK → See step   4 

1. Disconnect the 3A instrument panel junction block assembly connector.
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   A43-1 (HDLO) - 3A-43	Always	Below 1 Ω
   A43-1 (HDLO) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Remove the instrument panel junction block assembly. Refer to REMOVAL [06/2012 - ] .
   Fig 1: Identifying Instrument Panel Junction Block Assembly Connector Terminals

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

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   3A-43 - MB-15 (HRLY)	Always	Below 1 Ω
   3A-43 - Body ground	Always	10 kΩ or higher

   TEXT IN ILLUSTRATION
   
   

   *a	Component without harness connected (Instrument Panel Junction Block Assembly)

NG → See step   5 

OK → See step   6