Matt0987

Hey there folks, I have recently bought a 2004 A4. It is a great car. As it is used it has a couple of items to be repaired/replaced. These items I have under control.

However, one I am having difficulty with the information center between the speedo and tach. It says the rear driver's side brake light is out when, in reality, all lights - including this one - are performing as they should.

I will mention that I have done an hour or so of searching this issue here in the search engine but have not found anything relating to this.

Anyone have some input regarding this brake light out warning light issue?

John535is

Start with the simplest solution and just replace the bulb with a new genuine one. I know it sounds trivial but I had a similar issue on a BMW and I found the previous owner had just used a generic brand bulb, it worked but the alarm came on just like your issue.

The system triggers an alarm if the power draw is incorrect, normally open circuit when the bulb element fails but it will also trigger for a low or high power draw. Same reason some of the LED conversions set the alarm off, just the power draw outside of the programmed tolerance.

So, try a new (prefer genuine) bulb, or just swap the sides to prove if it's the bulb not the fitting.
Failing that you need to start looking at the terminals on the fitting itself. Check for corrosion or a loose fitting bulb, check the plug connection is clean and the connections are clean and the plug is connected correctly. Check the wiring loom has not been damaged in the trunk.
Do you have a tow connection? if so, check the wiring loom and the connection plug for damage or corrosion.

Matt0987

Replaced the bulb w/ new and the carrier that the bulbs plug into. Not fixed. I am looking for other ideas.