Kia Forte: Auto Light Sensor Inspection

In the state of IGN1 ON, when multifunction switch module detects auto light switch on, tail lamp relay output and head lamp low relay output are controlled according to auto light sensor's input.

The auto light control doesn't work if the pin sunlight supply (5V regulated power from Ignition 1 power to sunlight sensor) is in short circuit with the ground.

If IGN1 ON, The BCM monitors the range of this supply and raises up a failure as soon as the supply’s voltage is out of range. Then this failure occurs and as long as this is present, the head lamp must be turned on without taking care about the sunlight level provided by the sensor.

This is designed to prevent any head lamp cut off when the failure occurs during the night.

Circuit Diagram

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Auto Light Sensor Removal

1. Disconnect the negative (-) battery terminal. 2. Remove the auto light sensor (A) from crash pad upper side by using screw (-) driver. ...

See also:

Positive Crankcase Ventilation (PCV) Valve Inspection
1. Insert a thin stick (A) into the PCV valve (B) from the threaded side to check that the plunger movement.    ...

Circuit Diagram
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Front Hub / Knuckle Installation
1. Install in the reverse order of removal.    Use a SST (09581-11000) when ...