Warning Signs of a Failing Lighting Control Module
- Dim or flickering headlights
- Headlights that won't turn on or off
- Turn signals that don't work correctly
- Error messages on your dashboard related to lighting
- Interior lights malfunctioning
- Problems with automatic headlight leveling
Testing the Lighting Control Module
It can be tricky to know if the lighting control module is the problem. Here's how to check:
- Check the Bulbs: Make sure all your bulbs are good. A blown bulb can sometimes cause strange behavior.
- Inspect Fuses and Relays: Look for blown fuses or faulty relays related to the lighting system. Replace any that are bad.
- Use a Scan Tool: A mechanic can use a scan tool to read error codes from the lighting control module. This can help pinpoint the problem.
- Swap with a Known Good Module: If possible, try swapping your module with one from a working vehicle to see if the problem goes away. Note: This should only be done by a professional.
Common Causes of Failure
- Water damage or corrosion
- Electrical surges
- Overheating
- Normal wear and tear over time
- Faulty wiring in the vehicle