Just got this in RockAuto's January newsletter & thought it good to share:
Headlamp Level Sensors |
There used to only be high beams and low beams. Now I often am not sure what sort of light is shining in my face. Did that driver just flash his high beams at me or are his vehicle's headlamp assemblies not properly bolted down and bouncing around a bit? Newer HID and now LED headlamp systems continuously adjust headlight aim. If your vehicle has one of these automatic headlight aiming systems and you have trouble seeing and/or are blinding oncoming drivers then your vehicle may have Headlamp Level Sensor problems. You might expect headlamp level sensors to be part of the headlamp assembly, but they are actually typically mounted on the vehicle's rear suspension or on both the front and rear suspensions. The mechanical arms on the headlamp level sensors detect when the suspension compresses or expands and that information is used to adjust the aim of the headlights using motors in the headlamp assemblies. Typical Headlamp Level Sensors The headlamp level sensor is often the first part of the automatic headlight system to fail because it is located in the harsh environment under the vehicle. Water and salt may seep into the sensor or its electrical connector. Debris may damage the slender mechanical arms that connect the sensor to the suspension. The sensors may also be inadvertently damaged when suspension or exhaust components are replaced. A failing headlamp level sensor may generate a computer trouble code, but there may not be a trouble code if the sensor's mechanical arm is broken or bent. The computers will just assume the suspension is constantly being compressed or expanded by some unusual load inside the vehicle or by some unusually steep or curvy road and misaim the headlights accordingly. It may be necessary to get under the car and inspect the headlamp level sensors for physical damage. Replacing headlamp level sensors typically requires removing and reinstalling a couple of bolts and the electrical connector and then briefly driving the vehicle until the automatic headlamp aiming system calibrates itself. Consult your vehicle's owners manual and/or repair manual (found under "Literature" at RockAuto.com) for specific installation and calibration instructions. See the Headlamp Level Sensors for your specific vehicle under "Body & Lamp Assembly" in the RockAuto.com catalog. Tom Taylor, RockAuto.com |