LIGHTING SYSTEM TERMINALS OF ECU


  1. CHECK INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY AND MAIN BODY ECU

    A003T11E02

    1. Disconnect the 2A, 2B, 2C, 2E*1, 2F*2 and E121 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 GR - Body ground ACC power supply Power switch on (ACC) 11 to 14 V
      Power switch off Below 1 V
      2B-25 - Body ground W - Body ground IG power supply Power switch on (IG) 11 to 14 V
      Power switch off Below 1 V
      2C-18 (BECU) - Body ground W - Body ground Battery power supply Always 11 to 14 V
      2E-1*1 - Body ground W - Body ground Battery power supply Always 11 to 14 V
      2F-1*2 - Body ground W - 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 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
      E121-3*2 (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 2A, 2B, 2C, 2E*1, 2F*2 and E121 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 (RFG0) - Body ground GR - Body ground Rear fog light drive output Light control switch tail position and rear fog light switch on Below 1 V
      Light control switch tail position 11 to 14 V
      2C-22 (DIM) - Body ground LG-B - 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 B - 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
      E120-1 (RFOG) - Body ground SB - Body ground Rear fog light switch input Rear fog light switch on Below 1 V
      Rear fog light switch off Pulse generation
      E120-5 (HU) - Body ground P - Body ground Dimmer switch high position signal input Dimmer switch in high position Below 1 V
      Dimmer switch in low position Pulse generation
      E120-8 (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
      E120-15 (DRLE) - Body ground BR - Body ground Daytime running light drive output Daytime running lights on Below 1 V
      Daytime running lights off 11 to 14 V
      E120-20 (CLTB) (*4) - Body ground W - Body ground 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
      E120-21 (CLTS) (*4) - Body ground Y - Body ground Automatic light control sensor signal input Power switch off Below 1 V
      Automatic light control system operates

      Pulse generation

      (See waveform 1)
      E120-27 (FFOG) - Body ground G - Body ground Front fog light switch input Front fog light switch on Below 1 V
      Front fog light switch off Pulse generation
      E120-28 (A) (*4) - Body ground V - 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
      E120-29 (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
      E120-30 (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 Pulse generation

      Tech Tips

      *1: for LHD

      *2: for RHD

      *3: w/ Theft Deterrent System

      *4: w/ Automatic Light Control System

      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. A003RHVE01

        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 HEADLIGHT LEVELING ECU ASSEMBLY


    1. Disconnect the A35 headlight leveling ECU assembly connector.

      A003SO5E17

    2. Measure the voltage and resistance between the specified terminals of the wire harness side connectors and body ground.

      Standard Voltage
      Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition
      A35-1 (IG) - Body ground L-B - Body ground IG power supply Power switch off Below 1 V
      Power switch on (IG) 11 to 14 V
      Standard Resistance
      Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition
      A35-9 (E1) - Body ground W-B - Body ground Ground Always Below 1 Ω

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

    3. Reconnect the A35 headlight leveling ECU assembly connector.

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

      Standard Resistance
      Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition
      A35-21 (SGR) - Body ground W-B - Body ground Rear height control sensor ground Always Below 1 Ω
      A35-23 (RH-) - Body ground W-B - Body ground Leveling motor RH ground Always Below 1 Ω
      A35-24 (LH-) - Body ground W-B - Body ground Leveling motor LH ground Always Below 1 Ω
      Standard Voltage
      Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition
      A35-3 (B2) - Body ground B - Body ground Low beam headlight signal input Low beam headlights on Below 1.5 V
      Low beam headlights off Above 5 V
      A35-5 (PRST) - Body ground B - Body ground Initialization signal input Terminal LVL and terminal GND of DLC3 connected Below 1 V
      Terminal LVL and terminal GND of DLC3 not connected Approx. 5 V
      A35-6 (WNG) - Body ground GR - Body ground Warning indicator drive output Warning indicator on Below 1 V
      Warning indicator off 11 to 14 V
      A35-10 (RHT) - Body ground P - Body ground Leveling motor RH power supply Power switch off Below 1 V
      Power switch on (IG) 11 to 14 V
      A35-11 (LHT) - Body ground W - Body ground Leveling motor LH power supply Power switch off Below 1 V
      Power switch on (IG) 11 to 14 V
      A35-12 (SBR) - Body ground R - Body ground Rear height control sensor power supply Power switch off Below 1 V
      Power switch on (IG) 4.75 to 5.25 V
      A35-16 (SPDR) - Body ground V - Body ground Vehicle speed signal input Vehicle is driven at approx. 20 km/h (12mph)

      Pulse generation

      (See waveform 1)
      A35-17 (RH+) - Body ground G - Body ground Leveling motor RH operation signal input With low beam headlights on, vehicle height not changed Below 1 V
      With low beam headlights on, change vehicle height and keep for more than 3 seconds. 1.0 to 14.4 V
      A35-18 (LH+) - Body ground BR-W - Body ground Leveling motor LH operation signal input With low beam headlights on, vehicle height not changed Below 1 V
      With low beam headlights on, change vehicle height and keep for more than 3 seconds. 1.0 to 14.4 V
      A35-19 (SHRL) - Body ground Y - Body ground Rear height control sensor signal input Power switch off Below 1 V
      Power switch on (IG) 0.5 to 4.5 V

      If the result is not as specified, the headlight leveling ECU assembly may have a malfunction.


      1. A003U7M

        Waveform 1

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