[t4tr]

I have an ongoing problem with my 2001 Jetta GL. Whenever I step on the brake or turn on the heater, or roll up the window or anything that pulls power, my lights dim momentarily. I realize that is common, but it is a noticeable amount of dimming. Also, I can sometimes cause enough load, like when I power the window up and hold the button for a second, so that the ABS light comes on, the BRAKE light illuminates on the dash and I get three successive beeps. Sometimes the beeps will repeat continuously and sometimes it stops after the first sequence. Sometimes I have to shut the car off and restart it to get it to stop. Anyone ever hear of such a thing happening?

 

[Pssst...passed you]

Sounds like a ground, most Linley under the battery tray is loose or coroded.

If you can get a real VAGCOM, not a cheap code reader dive into the abs modes and it may give more info as a stored subcode though.

 

[Twichel04]

My GTI used to do that too... annoying as hell. According to the owners manual, the ABS light on along with the BRAKE light flashing and the beeps, has something to do with brake proportioning. I eventually got used to it. Then one day, I was replacing the slave cyl, and had the battery out for about an hour... after that the problem never returned.... not sure what I did.... not sure if it had to do with the battery being out, allowing all the codes to clear, or if it had to do with me bleeding the system, but try disconnecting the battery...it's worth a shot.