LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Lexus >> 2002 >> SC 430 >> Repair and Diagnosis >> External Pages >> Different car >> Section 522 (Lighting) >> Lighting System >> Precaution
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Lighting System: Precaution

WARNING: This page is about a different car, the 2004 Lexus ES 330. However, it is still accessible from the selected car via links, so may be relevant.
  1. PRECAUTION OF HEADLAMP BULB REPLACEMENT 
    Fig 1: Identifying Lighting System Precaution
    G03484076Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. When any defects such as deformation, crack, dent, chipping, etc. are identified on the discharge headlamp (especially, on the light control ECU), replace the headlamp with a new one.
    2. Even if the operation seems to be normal, the fail-safe function may be defective.
    3. Since bulbs of the discharge headlamp and halogen bulbs (for headlamps and fog lights) have pressurized gas inside and can easily be broken if scratched or dropped, special care should be taken. When handling, hold the plastic or metal part and do not touch the glass part with bare hands.
    4. Touching the HV socket of the discharge headlamp with the headlamp dimmer switch ON could generate momentary high voltage of 20,000 V and lead to a serious accident.
    5. Never connect a tester to the high voltage socket of the discharge headlamp for measurement, as this leads to a serious accident because of high voltage.
    6. When performing operation related to the discharge headlamp, keep it away from water such as rain, turn off the light control switch, and disconnect the battery terminal and the connector of the light control ECU in advance to avoid electric shock.
    7. When performing operation related to the discharge headlamp, start it after assembling has been completely over and never light up without a bulb installed.
    8. Do not light up the discharge headlamp using another power source except vehicle's.
  2. HEADLIGHT BEAM LEVEL CONTROL ECU INITIALIZING 
    1. Initialize the headlight beam level control ECU.
      1. Initializing the headlight beam level control ECU would be required after work such as items shown in WORK ITEM SPECIFICATION .
        WORK ITEM SPECIFICATION

        Work Item
        A A work which should be performed when the vehicle height changes because of the height control sensor removal and installation or suspension replacement
        B Headlight beam level control ECU replacement with a new one
        NOTE:
        • Do not get into a vehicle while working.
        • Do not lean to a vehicle while working.

        HINT:

        • Before starting initializing, perform the following preparation.
        • Place the vehicle on a level surface.
        • Unload luggage from a vehicle as many as possible. Leave the tools and spare tire equipped in vehicle.
        • Let no one in vehicle.
      2. Perform the ECU initialization as following flow chart.
  1. CHECK INDICATOR AND INITIALIZING OPERATION 
    1. When turning IG switch to ON position from OFF position, check that the headlamp reflector moves correctly (initializing) and indicator for headlight beam level control operates.

      Standard: 

      Headlamp reflector: Headlamp reflector moves correctly. 

      HEADLAMP REFLECTOR MOVES CORRECTLY

      OK Go to step 3
      NG Go to step 2

      Indicator (work A): 

      Warning indicator light comes on for 3 secs., and then goes off. 

      Indicator (work B): 

      Warning indicator light comes on for 3 secs., and then blinks in 1 Hz. 

      WARNING INDICATOR LIGHT COMES ON FOR 3 SEC. THEN BLINKS IN 1Hz.

      OK Go to step 3
      NG Go to step 2

      HINT:

      When the warning indicator light keeps coming on, the ECU that failed initialization would be remained, but go to step "3", because it is possible to retry initialization.

  2. CHECK ECU, WIRE HARNESS, HEIGHT CONTROL SENSOR OR ACTUATOR 
  3. CHECK THAT INITIALIZING IS PERFORMED CORRECTLY 
    1. Using SST, connect terminal 4 and 8 of DLC 3.

      SST 09843-18040

      2. Fig 2: Identifying DLC3 Connector Terminal
      G03484077Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Turn the light control switch as following.

      TAIL-->HEAD-->TAIL-->HEAD-->TAIL-->HEAD-->TAIL--> HEAD-->TAIL.....

      HINT:

      Repeat the operation to switch more than 8 times.

    3. Check that the light control switch operation described on step "b" is performed correctly.

      Standard: 

      Work A: Warning indicator light blinks twice and then goes off. 

      Work B: Warning indicator light blinks and then goes off. 

      4. Fig 3: Identifying Blinking Pattern
      G03484078Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. OK: Go to next step 
    2. NG: GO TO STEP   5 
  4. INITIALIZING IS DONE CORRECTLY 
    1. Disconnect the SST from the DLC3. (Initializing is completed.)
  5. REPEAT THE OPERATION 
    1. Repeat the light control switch operation more than 20 times.

      If the ECU initialization cannot be done, repeat the procedure from step ( 1) after turning IG switch to OFF in each case. The following causes are considered.

      1. Work procedure is wrong.
      2. It is failed to connect the SST to DLC3.
      3. Timing to change the light control switch position is not appropriate.
      4. Turning the IG switch to ON position from OFF while working.
scientia non olet · About LEMON Manuals