Headlamp Control Module: Description and Operation

With the ignition SW turned ON, the current flows to TERMINAL 1 of the automatic light control sensor through ECU-IG fuse. Voltage is applied at all times to TERMINAL 2 of the automatic light control sensor through DOME-FR fuse, to TERMINAL 5�of the automatic light control sensor through the coil side of the head LP relay, and to TERMINAL 7 of the automatic light control sensor through the coil side of the taillight control relay.

AUTOMATIC LIGHT CONTROL SENSOR
When the light control SW is in AUTO position, if the automatic light control sensor detects a decrease in the ambient light (to between about 90 and 500 lux), the automatic light control sensor is activated. About 5 seconds after it is activated, current flows from current flows from head LP relay to TERMINAL 5 of automatic light control sensor and from taillight control relay to TERMINAL 7 of automatic light control sensor.

If the ambient light drops below about 90 lux, the automatic light control sensor is activated and about 3 seconds later current flows from current flows from head LP relay to TERMINAL 5 of automatic light control sensor and from taillight control relay to TERMINAL 7 of automatic light control sensor.

When the light control SW is at AUTO position and activation of the automatic light control sensor has turned ON the headlights and taillights, if the automatic light control sensor detects ambient light above about 1000 lux, the sensor is turned OFF after about 5 seconds, so the current flow from head LP relay to TERMINAL 5 of automatic light control sensor and from taillight control relay to TERMINAL 7 of Automatic Light Control Sensor stops, and the headlights and taillights turn OFF.