LIGHTING SYSTEM TERMINALS OF ECU


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

    A01EWY1E08

    1. Disconnect the instrument panel junction block assembly and main body ECU (multiplex network body ECU) connectors.

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

      Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition
      3D-31 (BECU) - Body ground V - Body ground Battery power supply Ignition switch off 11 to 14 V
      3E-1*1 - Body ground

      W*3 - Body ground

      B*4 - Body ground

      		 Battery power supply Ignition switch off 11 to 14 V
      3F-1*2 - Body ground W - Body ground

      If the result is not as specified, there may be a malfunction in the wire harness.

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

      Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition
      3B-7 (GND1) - Body ground W-B - Body ground Ground Always Below 1 Ω
      I12-3 (GND2) - Body ground W-B - Body ground Ground Always Below 1 Ω

      If the result is not as specified, there may be a malfunction in the wire harness.

    4. Reconnect the instrument panel junction block assembly and main body ECU (multiplex network body ECU) connectors.

    5. 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
      3D-7 - Body ground L - Body ground Parking light RH drive output Light control switch in tail or head position 11 to 14 V
      Light control switch off Below 1 V
      3D-8 - Body ground W - Body ground Parking light LH drive output Light control switch in tail or head position 11 to 14 V
      Light control switch off Below 1 V
      3D-9 - Body ground P - Body ground Taillight relay drive signal output Light control switch in tail or head position 11 to 14 V
      Light control switch off Below 1 V
      3D-12 (HRLY) - Body ground P - Body ground Headlight relay drive output Light control switch in head position Below 1 V
      Light control switch not in head position 11 to 14 V
      3D-35 (RFGO)*5 - Body ground B - Body ground Rear fog light drive output Light control switch in tail or head position, rear fog light switch on Below 1 V
      Light control switch in tail or head position, rear fog light switch off 11 to 14 V
      3D-38 (FFGO) - Body ground P - Body ground Front fog light drive output Light control switch in tail or head position, front fog light switch on Below 1 V
      Light control switch in tail or head position, front fog light switch off 11 to 14 V
      3D-39 (DIM) - Body ground W - Body ground High beam headlight drive output Dimmer switch in high or high flash position Below 1 V
      Dimmer switch in low position 11 to 14 V
      3C-5 - Body ground P - Body ground Taillight relay drive signal output Light control switch in tail or head position 11 to 14 V
      Light control switch off Below 1 V
      I13-5 (HU) - Body ground LG - Body ground Dimmer switch high position signal input Dimmer switch in high position Below 1 V
      Dimmer switch not in high position Pulse generation
      I13-8 (HF) - Body ground R - Body ground Dimmer switch high flash position signal input Dimmer switch in high flash position Below 1 V
      Dimmer switch not in high flash position Pulse generation
      I13-20 (CLTB) - I13-22 (CLTE) B - P Automatic light control sensor power supply output Ignition switch off Below 1 V
      Ignition switch ON, light control switch in AUTO position 11 to 14 V
      I13-21 (CLTS) - Body ground G - Body ground Automatic light control sensor signal input Ignition switch off Below 1 V
      Automatic light control system operates

      Pulse generation

      (See waveform 1)
      I13-23 (RFOG)*5 - Body ground L - Body ground Rear fog light switch input Rear fog light switch on Below 1 V
      Rear fog light switch off Pulse generation
      I13-27 (FFOG) - Body ground V - Body ground Front fog light switch input Front fog light switch on Below 1 V
      Front fog light switch off Pulse generation
      I13-28 (A) - Body ground G - 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
      I13-29 (HEAD) - Body ground P - Body ground Light control switch head position input Light control switch in head position Below 1 V
      Light control switch not in head position, ignition switch off Pulse generation
      Light control switch not in head position, ignition switch ON 11 to 14 V
      I13-30 (TAIL) - Body ground W - Body ground Light control switch tail position signal input Light control switch in tail or head position Below 1 V
      Light control switch in neither tail nor head position, ignition switch off Pulse generation
      Light control switch in neither tail nor head position, ignition switch ON 11 to 14 V

      • *1: for LHD

      • *2: for RHD

      • *3: 100A Type Generator Assembly

      • *4: 130A Type Generator Assembly

      • *5: w/ Rear Fog Light

      If the result is not as specified, the main body ECU (multiplex network body ECU) or instrument panel junction block assembly may have a malfunction.


      1. A01ETYFE01

        Waveform 1

        Item Content
        Tool setting 5 V/DIV., 5 ms./DIV.

        Tech Tips

        If the ambient light becomes brighter, width A becomes narrower.