What's the matter with the headlight range control malfunction?
2 Answers
It may be due to a damaged body height sensor, which is primarily used to collect body height signals for the control unit to adjust the headlight level. Check whether the headlight connector and the adjustment motor connector are functioning properly. Also, inspect if the headlight level sensor on the suspension is damaged. Introduction to the vehicle height sensor: Used in automotive air suspension and active suspension systems, its function is to detect the body height (the relative displacement between the body and the lower suspension arm or shock absorber lower bracket in the vertical direction). Power supply inspection: Disconnect the sensor connector, turn on the ignition switch, and check that the voltage at the power terminal of the wiring harness connector should be 12V.
Last time my headlight height kept fluctuating up and down, and the diagnosis revealed it was an issue with the level sensor. This component is installed on the chassis—it measures the angle when the car goes up or down slopes and automatically adjusts the headlight height to avoid dazzling oncoming drivers. If this sensor gets clogged with mud or the wiring shorts due to water ingress, the lights will act erratic. Another possibility is a seized adjustment motor at the back of the headlight; we’ve seen many cases where sand or dirt jams the motor gears. The rear suspension height sensor is also related—if its readings are off, the system won’t know how much to adjust. Of course, a faulty control module is common too, especially in older cars with aging circuit boards. My advice: first, thoroughly rinse the chassis at a car wash. If that doesn’t work, scan for trouble codes with a diagnostic tool. Whatever you do, don’t attempt manual adjustments—you might end up making the lighting even more chaotic.
