Repair Procedures: Inspection
Check if the auto light control operates like a timing chart shown below. Tail lamp output and head lamp (Low) output is controlled based on the auto light sensor's input (illumination intensity) when the Auto Light Switch in Multi-Function Switch is turned ON, and the vehicle is in IGN1 or IGN2 ON Mode. If IGN1 = ON, BCM detects this voltage, and if the voltage exceeds rated voltage, then auto light failure occurs. (below 4V or above 6V)
In the state of IGN1 ON, when multi function 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 does not work if the pin sunlight supply (5V regulated power from Ignition 1 power to sunlight sensor) is in short circuit with the ground. During IGN1 ON, the BCM monitors the range of this supply and alerts the failure as soon as the supply's voltage is out of range. When this failure occurs and persists, the head lamp must be turned on regardless of the sunlight level detected by the sensor. This is designed to prevent any head lamp cut off when the failure occurs during the night.