"One or Both Xenon Headlights Aiming Downwards. CAUSE Both sides are aiming downwards: * The most likely cause is a faulty or disconnected rear height sensor. In very extreme cases due to poor road conditions, both headlight assemblies could have the vertical aim ball socket adjuster disconnected, as noted below. Only one side is aiming downwards: * The cause could be a ""disconnected"" vertical aim ball socket adjuster, resulting from excessive road vibration or sharp impacts (pot holes) through the suspension to the headlight assembly. Important Note: Follow the procedure outlined in this bulletin first; replacing headlight assemblies for a vertical aim ball socket adjuster issue is an excessive repair."