LIGHTING SYSTEM TERMINALS OF ECU


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

    A004118E31
    Text in Illustration
    *A for LHD *B for RHD

    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
      2A-43 - Body ground G - Body ground ACC power supply Power switch on (ACC) 11 to 14 V
      Power switch off Below 1 V
      2B-25 - Body ground B - Body ground IG power supply Power switch on (IG) 11 to 14 V
      Power switch off Below 1 V
      2C-18 (BECU) - Body ground Y - Body ground Auxiliary battery power supply Power switch off 11 to 14 V
      2E-1*1 - Body ground W - Body ground Auxiliary battery power supply Power switch off 11 to 14 V
      2F-1*2 - Body ground W - 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 according to the value(s) in the table below.

      Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition
      2B-6 (GND1) - Body ground W-B - Body ground Ground Always Below 1 Ω
      L8-3 (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 or check for pulses according to the value(s) in the table below.

      Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition
      2B-26 (RFGO)*3 - Body ground BR - Body ground Rear fog light drive output Light control switch in tail position, rear fog light switch on Below 1 V
      Light control switch in tail position, rear fog light switch off 11 to 14 V
      2C-8 - Body ground LG - Body ground Front fog lights drive output Light control switch in tail position, front fog light switch on 11 to 14 V
      Light control switch in tail position, front fog light switch off Below 1 V
      2C-20 (PKB) - Body ground R - Body ground Parking brake switch input Parking brake switch on Below 1 V
      Parking brake switch off 11 to 14 V
      2C-22 (DIM) - Body ground Y - Body ground High beam headlights drive output Dimmer switch in high or high flash position Below 1 V
      Dimmer switch in low position 11 to 14 V
      2C-32 (HRLY) - Body ground G - 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
      L7-1 (RFOG)*3 - Body ground W - Body ground Rear fog light switch input Rear fog light switch on Below 1 V
      Rear fog light switch off Pulse generation
      L7-8 (HF) - Body ground LG - 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
      L7-15 (DRLE)*4 - Body ground G - 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
      L7-20 (CLTB) - L7-22 (CLTE)*5 R - B Automatic light control sensor power supply output Power switch off Below 1 V
      Power switch on (IG) and light control switch in AUTO position 11 to 14 V
      L7-21 (CLTS) - Body ground W - Body ground Automatic light control sensor signal input Power switch off Below 1 V
      Automatic light control system operates

      Pulse generation

      (See waveform 1)
      L7-27 (FFOG) - Body ground LG - Body ground Front fog light switch input Front fog light switch on Below 1 V
      Front fog light switch off Pulse generation
      L7-28 (A)*4 - Body ground W - 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
      L7-29 (HEAD) - Body ground L - Body ground Light control switch head position input Light control switch in head position Below 1 V
      Light control switch not in head position Pulse generation
      L7-30 (TAIL) - Body ground Y - 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 11 to 14 V

      • *1: for LHD

      • *2: for RHD

      • *3: w/ Rear Fog Light

      • *4: w/ Daytime Running Light

      • *5: w/ Automatic Light Control

      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. A0040UAE01

        Waveform 1

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

        Tech Tips

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

  2. CHECK POWER MANAGEMENT CONTROL ECU

    A003ZY2E84

    1. Disconnect the A20 power management control ECU connector.

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

      Standard Voltage
      Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition
      A20-15 (BL) - Body ground R - Body ground Back up light Power switch on (IG), shift lever in R 11 to 14 V

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