LIGHTING SYSTEM TERMINALS OF ECU


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

    B003YD6N18

    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-1 (BECU) - Body ground B - Body ground Auxiliary battery power supply Power switch off 11 to 14 V
      4E-1 - Body ground B - Body ground Auxiliary battery power supply Power switch off 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
      4B-7 (GND1) - 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
      4C-5 - Body ground B - Body ground Clearance light drive output Light control switch in tail or head position 11 to 14 V
      Light control switch off Below 1 V
      4D-28 - Body ground V - Body ground Taillight drive output Light control switch in tail or head position 11 to 14 V
      Light control switch off Below 1 V
      4C-29 - 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
      4C-25 - Body ground P - 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
      4D-12*1 - Body ground BE - Body ground Rear fog light drive output Light control switch in tail or head position, fog light switch in rear position 11 to 14 V
      Light control switch in tail or head position, fog light switch off Below 1 V
      4C-27*2 - Body ground L - 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
      K2-1 (DIM) - Body ground V - 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
      4C-15 - Body ground GR - Body ground Parking brake switch input Parking brake switch on Below 1 V
      Parking brake switch off 11 to 14 V
      K2-24 (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
      K2-10 (HF) - Body ground L - 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
      K2-19 (CLTB) - K2-21 (CLTE) GR - W Automatic light control sensor power supply output Power switch off Below 1 V
      Power switch on (IG), light control switch in AUTO position 11 to 14 V
      K2-20 (CLTS) - Body ground R - Body ground Automatic light control sensor signal input Power switch off Below 1 V
      Automatic light control system operating

      Communication waveform generation

      (See waveform 1)
      K2-3 (RLEW)*3 - Body ground B - Body ground Light control ECU RH signal input Power switch on (IG), light control switch off 11 to 14 V
      Power switch on (IG), light control switch in head position Pulse generation
      K2-16 (LLEW)*3 - Body ground LG - Body ground Light control ECU LH signal input Power switch on (IG), light control switch off 11 to 14 V
      Power switch on (IG), light control switch in head position Pulse generation
      K2-23 (RFOG)*1 - Body ground P - Body ground Fog light switch rear position input Fog light switch in rear position Below 1 V
      Fog light switch off, power switch off Pulse generation
      K2-26 (FFOG)*2 - Body ground W - Body ground Fog light switch front position input Fog light switch in front position Below 1 V
      Fog light switch off, power switch off Pulse generation
      K2-8 (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, power switch off Pulse generation
      K2-12 (HEAD) - Body ground Y - Body ground Light control switch head position input Light control switch in head position Below 1 V
      Light control switch not in head position, power switch off Pulse generation
      K2-22 (TAIL) - Body ground B - Body ground Light control switch tail position signal input Light control switch in tail or head position Below 1 V
      Light control switch not in tail or head position, power switch off Pulse generation
      K1-4 (MILE)*4 - Body ground LG - Body ground Door mirror foot lights drive output Door mirror foot light operating 11 to 14 V
      Door mirror foot light not operating Below 1 V

      • *1: w/ Rear Fog Light

      • *2: w/ Front Fog Light

      • *3: for LED Headlight

      • *4: for Power Mirror Control System (w/o Memory)

      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. A00235GN01

        Waveform 1

        Item Content
        Tool setting 2 V/DIV., 10 ms./DIV.

        Tech Tips

        The communication waveform changes according to the surrounding brightness.

  2. CHECK COMBINATION METER ASSEMBLY

    A00235RN05

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

      Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition
      K4-4 (ER) - Body ground P - Body ground Turn signal switch right signal input Turn signal switch in neutral position 11 to 14 V
      Turn signal switch in right turn position Below 1 V
      K4-5 (EL) - Body ground GR - Body ground Turn signal switch left signal input Turn signal switch in neutral position 11 to 14 V
      Turn signal switch in left turn position Below 1 V
      K4-11 (HZSW) - Body ground W - Body ground Hazard warning signal switch signal (Input) Power switch on (IG), hazard warning signal switch not pressed 11 to 14 V
      Power switch on (IG), hazard warning signal switch pressed Below 1 V
      K4-12 (HAZM) - Body ground B - Body ground Hazard warning signal switch signal (Output) Power switch on (IG), hazard warning signal switch not pressed 11 to 14 V
      Power switch on (IG), hazard warning signal switch pressed Below 1 V

  3. CHECK OUTER MIRROR CONTROL ECU ASSEMBLY LH (for Power Mirror Control System (w/ Memory))

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  4. CHECK OUTER MIRROR CONTROL ECU ASSEMBLY RH (for Power Mirror Control System (w/ Memory))

    Click here

  5. CHECK POWER MANAGEMENT CONTROL ECU

    A00225FN69

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

      Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition
      K32-8 (BL) - Body ground R - Body ground Back-up light relay drive output Power switch on (IG), shift lever in R 11 to 14 V
      Power switch on (IG), shift lever not in R Below 1 V