[Jbar2016]

I am new to vw and just picked up an 07 rabbit and it has a few issues i need to take care of.

So i have the bulb light illuminated on the dash and i had someone check the brake lights, and i checked all the other bulbs. I am having trouble finding the dead bulbs. The only place that is questionable is the tail lights, the outside half of each circle tail light illuminates when the parking lights are on. Are the taillights suppose to illuminate the entire circle or only half circle??

 

[GTI's]

They should be full circle.

 

[Jbar2016]

Ok awesome, thanks for the info i will buy some bulbs tomorrow and update accordingly

 

[Jbar2016]

Thank you for answering my question i replaced the bulbs and the light went out thanks a bunch

 

[Marek K]

Glad you solved your issue.

It's worth repeating how the stock North American tail lights work on both the Mk5 Jettas and Rabbits. In most other/earlier cars, each bulb (or bulb filament) was on a specific circuit, and was either Off or On.

The NA Mk5's use Pulse Code Modulation (PCM), which in the case of the tail lights controls the brightness of the bulbs depending on what signal the housing gets from the computer. Each 7506 bulb on each semi-circle has only one filament, but can glow at two different brightnesses.

Here, when the running lights are on, the full circle illuminates at a medium brightness.

For brake lights, the inside semi-circles illuminate bright.

And for turn signals, the outside semi-circles blink bright.

So if both your inside bulbs were burned out, that also means your brake lights weren't working -- except for the high-center brake light.

European stock Mk5 tail lights work quite differently...

 

[GTI's]

Fwiw the Rabbit /GTI/R the braking lights are full circles the turns are semi.

 

[Marek K]

Fwiw the Rabbit /GTI/R the braking lights are full circles the turns are semi.

Argh, I guess you're right. And the sedans would be the same. I was talking from memory -- both our Mk5 sedans have had Euro LED tail lights for over a decade, and our daughter's Rabbit has Euro OEM incandescent tail lights.

I hate it when you have to correct me...

But the other part is true -- PCM, with single-filament bulbs that light up at two different brightnesses. People often think they must be dual-filament bulbs.