Ambient Light Sensor: Testing and Inspection

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




Auto off function:
INSPECT AUTOMATIC LIGHT CONTROL SYSTEM
a. Gradually expose the sensor.
b. Check the headlights and the accessory lights should turn OFF.

INSPECT LIGHT-OFF CONDITION
a. Turn the ignition switch ON.
b. Gradually cover the top of the sensor. Lights auto ON:

c. Check that the lights go off under the following conditions.
1. Light control switch is OFF.
2. The area surrounding the sensor gets bright.
3. The driver's door is opened with the ignition switch OFF.

INSPECT LIGHT-ON CONDITION
a. Open the driver's door while the ignition switch is OFF.
b. Turn the light control switch to AUTO leaving the door open and cover the top of the sensor, and verify that the lights go on when the ignition switch is turned ON.







Connector disconnected:
INSPECT AUTOMATIC LIGHT CONTROL SENSOR CIRCUIT
Disconnect the connector from the sensor and inspect the connector on the wire harness side, as shown in the table.
If circuit is as specified, perform the inspection.
If the circuit is not as specified, inspect the circuit connected to other parts.




Connector connected:
INSPECT AUTOMATIC LIGHT CONTROL SENSOR CIRCUIT
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.