lemon-mirror:
Home >> Toyota >> 2001 >> Sequoia Limited, RWD >> Repair and Diagnosis >> Body & Frame >> Body, Cab Control Systems >> Body Control Systems >> Component Tests >> Automatic Light Control System & Automatic Light Control Sensor

Automatic Light Control System & Automatic Light Control Sensor

  1. To check the auto on and auto off operation of automatic light control system, turn ignition on. Place headlight control switch in position No. 3 (AUTO position). Gradually cover top of automatic light control sensor while noting headlight operation. Automatic light control sensor is located at driver's side corner of instrument panel, near end of air vent. See Fig 1. Headlights along with park lights, taillights, side marker lights and instrument panel lights should come on. Gradually expose automatic light control sensor while noting headlight operation. Headlights along with park lights, taillights, side marker lights and instrument panel lights should turn off.
  2. Ensure ignition is on and headlight control switch is in position No. 3 (AUTO position). Gradually cover top of automatic light control sensor so headlights, park lights, taillights, side marker lights and instrument panel lights come on. Check that these lights turn off when headlight control switch is placed in OFF position or ignition is turned off and 30 seconds has passed since the doors were closed.
  3. Remove cover from top of automatic light control sensor and turn ignition off. Place headlight control switch in OFF position. Open driver's side front door with ignition off. Place headlight control switch in position No. 3 (AUTO position). Ensure driver's side front door is open. Gradually cover top of automatic light control sensor. Turn ignition on and ensure headlights along with park lights, taillights, side marker lights and instrument panel lights come on. Turn ignition off and place headlight control switch in OFF position. If automatic light control system does not operate as specified, go to next step.
  4. It may be necessary to adjust sensitivity of automatic light control sensor to determine at what light condition the automatic light control system operates. Sensitivity of automatic light control sensor may be adjusted by rotating knob on automatic light control sensor. If response of automatic light control sensor is too quick, rotate knob counterclockwise. If response of automatic light control sensor is too slow, rotate knob clockwise. Recheck operation of automatic light control system. If automatic light control system does not operate properly, go to next step. If automatic light control system operates properly, no further testing is required.
  5. Individual component testing for automatic light control sensor is not available from manufacturer. To check automatic light control sensor circuit, obtain access to automatic light control sensor with electrical connector installed. Note electrical terminal identification with electrical connector installed. See Fig 2.
  6. Turn ignition on. Place headlight control switch in position No. 3 (AUTO position) and ensure vehicle is an area where surrounding lighting is bright. Check for continuity and proper voltage between specified electrical terminals on electrical connector for automatic light control sensor under specified conditions. See AUTOMATIC LIGHT CONTROL SENSOR SPECIFICATIONS  table. Also, check that when vehicle is in direct sun light with automatic light control sensor exposed to sunlight that the headlights turn on. If continuity or proper voltage does not exist, go to next step. If continuity and proper voltage exists, replace automatic light control sensor and check operation of automatic light control system.
  7. Turn ignition off. Disconnect electrical connector from automatic light control sensor. Note electrical terminal identification on wiring harness side of electrical connector. See Fig 2. Check for continuity and proper voltage between specified electrical terminals on electrical connector for automatic light control sensor under specified conditions. See AUTOMATIC LIGHT CONTROL SENSOR SPECIFICATIONS  table. If continuity and proper voltage exists, replace automatic light control sensor and check operation of automatic light control system. If continuity or proper voltage does not exist, repair wiring harness and electrical connector on electrical circuit as necessary and check operation of automatic light control system. See WIRING DIAGRAMS in HEADLIGHT SYSTEMS article or WIRING DIAGRAMS in DAYTIME RUNNING LIGHTS article.
    AUTOMATIC LIGHT CONTROL SENSOR SPECIFICATIONS

    Condition & Tester Connection Condition Result
    With Electrical Connector Installed On Automatic Light Control Sensor, Check Between Body Ground & Specified Terminal
    1 Ignition Switch In ON Position 9.5 Volts Or More
    1 Ignition Switch In LOCK Or ACC Position No Voltage
    3 Constantly Continuity
    Vehicle In Direct Sun Light With Automatic Light Control Sensor Exposed To Sunlight Headlights Should Turn On
    With Electrical Connector Disconnected At Automatic Light Control Sensor, Check Between Body Ground & Specified Terminal
    1 Ignition Switch In ON Position Battery Voltage
    1 Ignition Switch In LOCK Or ACC Position No Voltage
    3 Constantly Continuity
    4 Ignition Switch In ON Position 5.2-9.0 Volts
    4 Ignition Switch In LOCK Or ACC Position No Voltage
    Fig 1: Locating Automatic Light Control Sensor
    G00023105Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    Fig 2: Identifying Electrical Connector Terminals At Electrical Connector For Automatic Light Control Sensor
    G00015647Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002