Ambient Light Sensor: Testing and Inspection

INSPECT AUTOMATIC LIGHT CONTROL AUTO ON:
a. Turn the ignition switch ON.
b. Turn the light control switch to AUTO.
c. Gradually cover the top of the sensor.
d. Verify that the lights should turn ON the accessory lights and the headlights.




INSPECT AUTOMATIC LIGHT CONTROL AUTO OFF:
a. Gradually expose the sensor.
b. Verify that the lights should turn OFF the headlights and the accessory lights.

ADJUST AUTOMATIC LIGHT CONTROL SENSOR
Using the LEXUS hand-held tester with customize soft installed, adjust the automatic light control sensor.
- If response is too quick, turn the knob counterclockwise.
- If response is too slow, turn the knob clockwise.

INSPECT AUTOMATIC LIGHT CONTROL SENSOR CIRCUIT

Connector disconnected







Disconnect the connector from the sensor and inspect the connector on the wire harness side, as shown in the chart.
If circuit is as specified, perform the inspection on the following condition.
If the circuit is not as specified, inspect the circuit connected to other parts.

Connector connected







Connect the wire harness side connector to the sensor and inspect wire harness side connector from the back side, as shown.

HINT:
- Ignition switch ON.
- Light control switch AUTO.
- Vehicle's surroundings are bright.

If circuit is as specified, try replacing the sensor with a new one.
If the circuit is not as specified, inspect the circuit connected to other parts.