LIGHTING SYSTEM TERMINALS OF ECU


  1. CHECK HEADLIGHT LEVELING ECU (for HID Headlight)

    A01J541E21

    1. Disconnect the H17 headlight leveling ECU connector.

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

      Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition
      H17-1 (IG) - Body ground R-L - Body ground Ignition power supply Ignition switch off Below 1 V
      Ignition switch ON 11 to 14 V
      H17-9 (E1) - Body ground GR - 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 H17 headlight leveling ECU connector.

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

      Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition
      H17-3 (B2) - H17-9 (E1) P - GR Low beam headlight signal input Low beam headlights on Below 1 V
      Low beam headlights off 11 to 14 V
      H17-5 (SPDL) - H17-9 (E1) V - GR Initialization signal input Terminal LVL and terminal CG of DLC3 connected Below 1 V
      Terminal LVL and terminal CG of DLC3 not connected 4.5 to 5.5 V
      H17-6 (WNG) - H17-9 (E1) B-L - GR Warning indicator drive output Warning indicator on Below 1 V
      Warning indicator off 11 to 14 V
      H17-10 (RH+) - H17-9 (E1) R - GR Leveling motor RH power supply Ignition switch off Below 1 V
      Ignition switch ON 11 to 14 V
      H17-11 (LH+) - H17-9 (E1) Y - GR Leveling motor LH power supply Ignition switch off Below 1 V
      Ignition switch ON 11 to 14 V
      H17-12 (SBR) - H17-21 (SGR) B - G Rear height control sensor power supply Ignition switch off Below 1 V
      Ignition switch ON 4.75 to 5.25 V
      H17-16 (SPDR) - H17-9 (E1) L - GR Vehicle speed signal input Vehicle is driven at approximately 20 km/h (12 mph)

      Pulse generation

      (See waveform 1)
      H17-17 (RHE) - H17-9 (E1) LG - GR 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
      H17-18 (LHE) - H17-9 (E1) W - GR 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
      H17-19 (SHRL) - H17-21 (SGR) L - G Rear height control sensor signal input Ignition switch off Below 1 V
      Ignition switch ON 0.5 to 4.5 V
      H17-21 (SGR) - H17-9 (E1) G - GR Rear height control sensor ground Always Below 1 Ω
      H17-23 (RH-) - H17-9 (E1) B-O - GR Leveling motor RH ground Always Below 1 Ω
      H17-24 (LH-) - H17-9 (E1) GR - GR Leveling motor LH ground Always Below 1 Ω

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


      1. A01J6SFE03

        Waveform 1

        Item Content
        Terminal No. (Symbol) H17-16 (SPDR) - H17-9 (E1)
        Tool setting 5 V/DIV., 20 ms./DIV.
        Condition Vehicle is driven at approximately 20 km/h (12 mph)

        Tech Tips

        When the system is functioning normally, one wheel revolution generates 4 pulses. As the vehicle speed increases, the width indicated by (A) in the illustration narrows.

  2. CHECK AUTOMATIC LIGHT CONTROL SENSOR (for HID Headlight)

    A01J4XRE03

    1. Disconnect the A39 automatic light control sensor connector.

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

      Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition
      A39-1 (IG) - Body ground R-L - Body ground Ignition power supply Ignition switch off Below 1 V
      Ignition switch ON 11 to 14 V
      A39-2 (B) - Body ground L-Y - Body ground Battery power supply Always 11 to 14 V
      A39-6 (A) - Body ground P-L - Body ground Ground Headlight dimmer switch in AUTO position Below 1 Ω
      Headlight dimmer switch not in AUTO position 10 kΩ or higher

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

    3. Reconnect the A39 automatic light control sensor connector.

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

      Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition
      A39-3 (CTY) - Body ground R-B - Body ground Front door courtesy light switch LH signal input Front door LH open Below 1 V
      Front door LH closed 11 to 14 V
      A39-5 (H) - Body ground GR - Body ground H-LP RLY relay drive output

      Ignition switch ON

      Headlight dimmer switch in AUTO position

      Automatic light control sensor covered with a hand

      Low beam headlights come on

      		 Below 1 V

      Ignition switch ON

      Headlight dimmer switch in AUTO position

      Automatic light control sensor exposed to ambient light

      Low beam headlights turn off

      		 11 to 14 V
      A39-7 (T) - Body ground LG-B - Body ground Taillight relay drive output

      Ignition switch ON

      Headlight dimmer switch in AUTO position

      Automatic light control sensor covered with a hand

      Taillights come on

      		 Below 1 V

      Ignition switch ON

      Headlight dimmer switch in AUTO position

      Automatic light control sensor exposed to ambient light

      Taillights turn off

      		 11 to 14 V

      If the result is not as specified, the automatic light control sensor may have a malfunction.