Brake Lights Stuck Always On in Your VW or Audi? Here’s How I Fixed It Without the Dealer

A few weeks ago, I noticed that the brake lights on my 2016 Volkswagen Jetta were always on—even when the brake pedal wasn’t pressed. At first, I thought it might just be a stuck pedal or a simple switch issue. But it quickly became clear this wasn’t your average bulb or pedal spring problem.

The local VW dealership wanted $300 just to diagnose the issue . No repairs—just diagnostics. I wasn’t ready to shell out that money, especially without knowing the real problem. That’s when I decided to take matters into my own hands using the YOUCANIC full system diagnostic scanner . And I’m glad I did—it not only saved me hundreds of dollars, but it also helped me understand a lot more about how modern brake light systems work in Volkswagens and other vehicles in the VAG group (Audi, VW, Seat, Skoda).

Step 1: Scanning the Car with the YOUCANIC Scanner

I connected my YOUCANIC scanner to the OBD2 port and performed a full system scan. In the ABS (anti-lock braking system) control module , I found a very telling fault code:

• DTC: P020E / 00526
• Description : Brake light switch (F), sporadic – implausible signal (008)

At this point, I strongly suspected that the brake light switch was the issue. But here’s where things get interesting—on many cars, the brake light switch is above the brake pedal, easily accessible from the driver’s footwell. That’s where I looked first. However, on the 2016 VW Jetta and many other Audi and Volkswagen models , the brake light switch is a Hall effect sensor mounted on the master cylinder , near the brake booster , in the engine bay.

Step 2: Replacing the Brake Light Switch (And Still No Fix)

I sourced a new brake light switch sensor. The brake light switch on many newer Audis and VWs, including my 2016 VW Jetta, clips onto the  master cylinder body .

Replacement was straightforward, but I had to take out the battery, though.

To my disappointment, the brake lights were still on . That meant either:

1. The issue was elsewhere in the circuit, or
2. The brake light switch sensor wasn’t getting power , or
3. There was a short somewhere else in the lighting system.

What made it even weirder was that the car would start without pressing the brake pedal , which isn’t normal.

Typically, the ECU needs confirmation from the brake switch signal to engage the starter relay, especially in automatic transmission vehicles.

Step 3: Ruling Out a Short in the Taillight Circuits

I thought maybe a wrong bulb type had been installed at some point and was backfeeding current between the parking light and brake light circuits. This is more common than you might think, especially when dual-filament bulbs are mismatched or installed improperly.

To rule this out, I unplugged the rear taillight harnesses , left and right. But the third brake light (on the rear windshield) remained illuminated. The car also still started without pressing the brake pedal . That ruled out any shorts in the tail lamp assemblies.

Step 4: Checking the Brake Light Fuse

Digging deeper, I used the YOUCANIC scanner to view live data and noticed that the brake pedal position was always reported as “ON” , even when untouched. That’s when I decided to check the fuses .

And bingo.

I found that Fuse F10  was b lown in the  fuse box under the hood on the driver’s side . According to VW schematics, F10 is a 5-amp fuse labeled for:

Brake light switch / clutch position sender

Once I replaced this fuse with a fresh 5A fuse, everything went back to normal :

• The brake lights finally turned off when they should.
• The live data from the brake switch started showing correctly.
• And the car now required the brake pedal to be…