The module receives signals from a controller — this could be triggered by schedules, sensor inputs, app commands, or voice. Based on those signals, it adjusts the lights: turning them on/off, dimming, changing color (if compatible), or even dynamically. This guide will provide you with the technical insights and practical steps needed to identify a failing unit, helping you understand how to know if abs module is bad without a costly trip to the dealership. By the end of this article, you will be able to distinguish between a simple sensor issue. A lighting control module is the “control center” for your lighting system. The LCM recognizes that the switch is in "Auto" mode. The coding looks OK to me unless I am missing a secret someplace. I even checked the LCM (light control module). When you have your ABS and traction control light on simultaneously, it typically signals issues with wheel speed sensors, brake fluid levels, or electrical components. While you can drive cautiously with these lights illuminated, scanning with an OBD-II code reader helps identify the root cause. Once those connections break, the module loses the ability to read solenoid feedback or command the valves. In this video I show how I diagnosed and fixed a Mercedes fault where the auto lights stopp.