Repair Procedures: Inspection
Check if the auto light control operates as in the timing chart displayed below. Tail lamp output and headlamp (Low) output are 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 multifunction switch module detects auto light switch on, tail lamp relay output and headlamp low relay output are controlled according to auto light sensor's input. The auto light control doesn't work if the pin sunlight supply (5 V 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 voltage is out of range. Then, this failure occurs and as long as this is present, the headlamps must be turned on regardless of the sunlight level provided by the sensor. This is designed to prevent any headlamp cut off when the failure occurs during the night.