LIGHTING SYSTEM TERMINALS OF ECU


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

    B00403HC01
    *A Main Body ECU (Multiplex Network Body ECU) with 2 Connectors - -
    *1 Main Body ECU (Multiplex Network Body ECU) - -
    *a 2 Connectors - -
    A0028JSC01
    *A Main Body ECU (Multiplex Network Body ECU) with 3 Connectors - -
    *1 Main Body ECU (Multiplex Network Body ECU) - -
    *a 3 Connectors - -

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

    2. Measure the voltage on the wire harness side connector according to the value(s) in the table below.

      Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition
      4F-32 - Body ground BE - Body ground Battery power supply Always 11 to 14 V
      4K-1 - Body ground B - Body ground Battery power supply Always 11 to 14 V

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

    3. Measure the resistance on the wire harness side connector according to the value(s) in the table below.

      Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition
      4D-11 - Body ground LA - 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
      4A-48 - Body ground B - Body ground Battery power supply Always 11 to 14 V
      4D-23 - Body ground BE - Body ground Battery power supply Always 11 to 14 V
      4F-4 - Body ground LG - Body ground Clearance lights drive output Light control switch in tail or head position 11 to 14 V
      Light control switch off Below 1 V
      4H-17 - Body ground LA-Y - Body ground Taillights (rear combination light assembly) drive output Light control switch in tail or head position 11 to 14 V
      Light control switch off Below 1 V
      4H-16 - Body ground LA-Y - Body ground Taillights (rear light assembly), license plate lights and rear fog lights*2 drive output Light control switch in tail or head position 11 to 14 V
      Light control switch off Below 1 V
      4H-26 - Body ground*1 LG - Body ground Rear fog light relay power supply output Light control switch in tail or head position 11 to 14 V
      Light control switch off Below 1 V
      4F-27 - Body ground R - 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
      4F-26 - Body ground L - Body ground Daytime running light system drive output Daytime running light system operating Below 1 V
      Daytime running light system not operating 11 to 14 V
      4F-25 - Body ground GR - Body ground Front fog light drive output Light control switch in tail or head position, fog light switch in front position Below 1 V
      Light control switch in tail or head position, fog light switch off 11 to 14 V
      F19-1 (DIM) - Body ground BE - 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
      4F-28 - Body ground G - Body ground Parking brake switch input Ignition switch ON, parking brake switch on Below 1 V
      Ignition switch ON, parking brake switch off 11 to 14 V
      F19-24 (HU) - Body ground Y - Body ground Dimmer switch high position signal input Dimmer switch in high position Below 1 V
      Dimmer switch not in high position 11 to 14 V or Pulse generation
      F19-10 (HF) - Body ground SB - 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 11 to 14 V or Pulse generation
      F19-19 (CLTB) - F19-21 (CLTE) L - G Automatic light control sensor power supply output Ignition switch off, dimmer switch off, 2 minutes after all doors closed Below 1 V
      Ignition switch ON 11 to 14 V
      F19-20 (CLTS) - Body ground R - Body ground Automatic light control sensor signal input Ignition switch off, dimmer switch off, 2 minutes after all doors closed Below 1 V
      Ignition switch ON

      Communication waveform generation

      (See waveform 1)
      F19-23 (RFOG) - Body ground*1 LG - Body ground Fog light switch rear position input Fog light switch in rear position Below 1 V
      Ignition switch off, fog light switch off 11 to 14 V or Pulse generation
      F19-26 (FFOG) - Body ground GR - Body ground Fog light switch front position input Fog light switch in front position Below 1 V
      Ignition switch off, fog light switch off 11 to 14 V or Pulse generation
      F19-8 (A) - Body ground B - Body ground Light control switch AUTO position signal input Light control switch in AUTO position Below 1 V
      Ignition switch off, light control switch not in AUTO position 11 to 14 V or Pulse generation
      F19-12 (HEAD) - Body ground W - Body ground Light control switch head position input Light control switch in head position Below 1 V
      Ignition switch off, light control switch not in head position 11 to 14 V or Pulse generation
      F19-22 (TAIL) - Body ground LG - Body ground Light control switch tail position signal input Light control switch in tail or head position Below 1 V
      Ignition switch off, light control switch not in tail or head position 11 to 14 V or Pulse generation
      F19-3 (RLEW) - Body ground*2 V - Body ground Light control ECU RH signal input Ignition switch ON, light control switch off 11 to 14 V
      Ignition switch ON, light control switch in head position Pulse generation
      F19-16 (LLEW) - Body ground*2 P - Body ground Light control ECU LH signal input Ignition switch ON, light control switch off 11 to 14 V
      Ignition switch ON, light control switch in head position Pulse generation

      • *1: w/ Rear Fog Light

      • *2: for LED Headlight

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


      1. A002AXON01

        Waveform 1

        Item Content
        Tool setting 2 V/DIV., 10 ms./DIV.
        Vehicle condition Ignition switch ON

        Tech Tips

        The communication waveform changes according to the surrounding brightness.

  2. CHECK COMBINATION METER ASSEMBLY

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  3. CHECK OUTER MIRROR CONTROL ECU ASSEMBLY LH (w/ Door Mirror Foot Light)

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  4. CHECK OUTER MIRROR CONTROL ECU ASSEMBLY RH (w/ Door Mirror Foot Light)

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