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DTC B1244: Light Sensor Circuit Malfunction

NOTE: If LEXUS scan tool is available, start test from step  1. If this scan tool is not available, start test from step  2.
  1. Using scan tool, check light sensor. Value of illumination rate should change from .8 to 22 milliseconds when light sensor is illuminated or covered by hand. If light sensor does not operate, replace light sensor. If light sensor operates, check wiring between light sensor and driver-side junction block. See WIRING DIAGRAMS . Repair or replace as necessary. If wiring is okay, replace body No. 2 ECU.
  2. Turn ignition on. Turn light control switch to AUTO. Gradually cover top of sensor. Headlights should come on. Uncover sensor. Headlights should turn off. If light sensor does not operate, replace light sensor. If light sensor operates, check wiring between light sensor and driver-side junction block. See WIRING DIAGRAMS . Repair or replace as necessary. If wiring is okay, replace body No. 2 ECU.
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