Autolight control system controls head/tail light automatically in accordance with detected intensity of illumination without extra signal of driver. It consists of autolightsensor, multifunction switch and head/tail lamp, and operates when the light switch is moved to AUTO position. Autolightsensor detects intensity of illumination and transforms it to voltage value and delivers it to BCM. According to this signal, BCM turns on or off head/tail lamp.
The ECM sets DTC B1901 if the supply voltage of autolightsensor is out of range.
Item | Detecting Condition | Possible Cause |
DTC Strategy | ● Check Voltage | ● Open or short in signal harness. ● Faulty BCM |
Enable Conditions | ● IGN ‘ON’ & Headlamp ‘AUTO’ | |
Threshold value | ● 4V< Output voltage <6V | |
Detecting time | ● 300ms | |
FAIL SAFE | - |
※ Operation of head/tail lamp as a function of AutolightSensor’s Input voltage.
Tail | Head Lamp | note | |
ON | 1.77±0.08(V) or less | 0.61±0.06(V) or less | |
OFF | 3.47±0.10(V) or more | 1.00±0.06(V) or more |
