ABS/Traction/Brake Lights Coming On - 2004 A4
 

Hey guys,

I'm having an issue with my 2004 A4, with the traction/ABS/brake lights coming on after driving for 10-15 mins, or driving over a wet road. Sometimes just the traction light will come on, other times all three. I had the battery recently replaced and changed out all the bulbs with HIDs and LEDS, including the brake lights. Now I've read it could be a bad ABS/speed sensor, but it seems like the problem only started after I replaced the bulbs and battery, but then again it also started snowing around the same time. Didn't have any issues in the summer and fall, traction control and everything worked fine. Always had these short beeps go off a few times whenever I start the car. So I'm not sure what the issue could be or where I should start. If I run an OBD II scanner, would it pinpoint the issue, or give me a false reading if it is the battery or brake lights?

Your help would be much appreciated. Oh and I'm new the forum, hope to see you guys around!

Re: ABS/Traction/Brake Lights Coming On - 2004 A4
 

Might want to quickly check the connectors for the wiring that goes to each ABS/speed sensor. With snow and all the other junk that gets thrown around maybe there's an intermittent connection somewhere.

Re: ABS/Traction/Brake Lights Coming On - 2004 A4
 

Just a thought based on motorcycle forum reading ... If you used inexpensive aftermarket HID kits for your replacement, you could be generating RF interference which wreaks havoc with sensitive electronics.

Mike

Re: ABS/Traction/Brake Lights Coming On - 2004 A4
 

I confirme, the hid ballast create interference. They should be installed underneath the sealed beam block. They should not be installed on a metal surface, it will amplify the interference.