AUTOMATIC HEADLIGHT BEAM LEVEL CONTROL SYSTEM TERMINALS OF ECU


  1. CHECK HEADLIGHT LEVELING ECU ASSEMBLY


    1. Disconnect the A34 headlight leveling ECU assembly connector.

      B000IR3E20

    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
      A34-1 (IG) - Body ground LG - Body ground IG power supply Ignition switch off Below 1 V
      Ignition switch ON 11 to 14 V
      Standard Resistance
      Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition
      A34-9 (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 A34 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
      A34-21 (SGR) - Body ground V - Body ground Rear height control sensor ground Always Below 1 Ω
      A34-23 (RH-) - Body ground G - Body ground Leveling motor RH ground Always Below 1 Ω
      A34-24 (LH-) - Body ground B - Body ground Leveling motor LH ground Always Below 1 Ω
      Standard Voltage
      Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition
      A34-3 (B2) - Body ground G - Body ground Low beam headlight signal input Low beam headlights on Below 1.5 V
      Low beam headlights off 5 V or higher
      A34-5 (SPDL) - Body ground V - Body ground Initialization signal input Terminals LVL and GND of DLC3 connected Below 1 V
      Terminals LVL and GND of DLC3 not connected 4.5 to 5.5 V
      A34-6 (WNG) - Body ground SB - Body ground Warning indicator drive output Warning indicator on Below 1 V
      Warning indicator off 11 to 14 V
      A34-10 (RH+) - Body ground R - Body ground Leveling motor RH power supply Ignition switch off Below 1 V
      Ignition switch ON 11 to 14 V
      A34-11 (LH+) - Body ground Y - Body ground Leveling motor LH power supply Ignition switch off Below 1 V
      Ignition switch ON 11 to 14 V
      A34-12 (SBR) - Body ground B - Body ground Rear height control sensor power supply Ignition switch off Below 1 V
      Ignition switch ON 4.75 to 5.25 V
      A34-16 (SPDR) - Body ground

      P - Body ground*1

      L - Body ground*2

      		 Vehicle speed signal input Vehicle driven at approx. 20 km/h (12mph)

      Pulse generation

      (See waveform 1)
      A34-17 (RHE) - Body ground W - 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, vehicle height changed and maintained for more than 3 seconds 1.0 to 14.4 V
      A34-18 (LHE) - Body ground LG - 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, vehicle height changed and maintained for more than 3 seconds 1.0 to 14.4 V
      A34-19 (SHRL) - Body ground R - Body ground Rear height control sensor signal input Ignition switch off Below 1 V
      Ignition switch ON 0.5 to 4.5 V

      • *1: for TMC, TMMR Made

      • *2: for TMMK Made

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


      1. B000MWTE01

        Waveform 1

        Item Content
        Tool setting 2 V/DIV., 2 ms./DIV.
        Vehicle condition Wheel being rotated