AUTOMATIC HIGH BEAM SYSTEM TERMINALS OF ECU

CHECK MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) AND INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

1. Measure the voltage and check for pulses according to the value(s) in the table below.

   Terminal No. (Symbol)	Wiring Color	Terminal Description	Condition	Specified Condition
   4C-29 - Body ground	R - Body ground	H-LP LH relay drive output	Light control switch in head position	Below 1 V
   			Light control switch not in head position	11 to 14 V
   O1-23 (AHBI) - Body ground	SB - Body ground	Auto high beam switch signal input	Auto high beam switch on	Below 1 V
   			Auto high beam switch off	11 to 14 V
   O2-1 (DIM) - Body ground	V - Body ground	H-LP RH/MIR HTR relay drive output*1 H-LP RH relay drive output*2	Light control switch in head position	Below 1 V
   			Light control switch not in head position	11 to 14 V
   O2-8 (A) - Body ground	P - Body ground	Light control switch AUTO position signal input	Light control switch in AUTO position	Below 1 V
   			Light control switch not in AUTO position	Pulse generation
   O2-19 (CLTB) - O2-21 (CLTE)	GR - W	Automatic light control sensor power supply output	Engine switch off	Below 1 V
   			Engine switch on (IG), light control switch in AUTO position	11 to 14 V
   O2-20 (CLTS) - Body ground	R - Body ground	Automatic light control sensor signal input	Engine switch off	Below 1 V
   			Engine switch on (IG)	Pulse generation (See waveform 1)
   O2-24 (HU) - Body ground	V - Body ground	Dimmer switch high position signal input	Dimmer switch in high position	Below 1 V
   			Dimmer switch not in high position	Pulse generation

   
   

   • *1: for LHD

   • *2: for RHD

   
   
   1. 

      Waveform 1

      Item	Content
      Tester Connection	O2-20 (CLTS) - Body ground
      Tool setting	2 V/DIV., 10 ms./DIV.
      Condition	Engine switch on (IG)

      Tip:

      The communication waveform changes according to the surrounding brightness.