ABS & BRAKE Warning Lights & Beeping & other questions

I probably just need to get friendly with some of my local Vag-Com ownin' TDI'ers (I have one one the way), but hopefully somebody can give me some direction here... I've already done a LOT of searching, but it seems like there are so many potential issues that I'm hoping someone can help me narrow this down (or maybe give ideas for other things to check). I've had my car since Friday and I really like it. It did come with some issues (thus my getting it for ~50% of what these things are going for right now ). When I got it, the ABS light was on and the BRAKE light was flashing. Otherwise, everything worked great. The person I got it from said a dealer service center diagnosed a bad ABS pump. While driving the car around Saturday, the glow plug light started flashing. I searched and tested and sure enough, no brake lights.

I replaced the brake switch this morning with a new purple one and now the ABS light and BRAKE light are intermittent and I get more beeping than before. Before it would just beep when started and then be quiet for the rest of the drive. I'm starting to wonder if it might just have a bad ground since that seems to cause similar symptoms.

If I go checking grounds, I've been reading I have to remove the battery. If I do that, it sounds like I might disable the stereo. How can I avoid that? I don't have the radio code (Monsoon). Can I get the radio code through Vag-Com?

The brake fluid level is about halfway between the Max and Min line. Could that be it? I would expect a beeping when it's at the Min line, but not half-way between. I think I need to change the fluid anyway. Any suggestions where to get it? Is standard DOT 4 from the local auto parts store okay?

Could it be a wheel speed sensor? Could one of those be activated if the tires are slightly different pressures from side to side?

I have a Bentley service manual on the way too, so hopefully I'll be able to answer more questions than I'm asking now.

Update: I got some DOT 4 and tried topping up the reservoir. It took quite a bit more than I thought it would. Now the ABS light is staying on and the BRAKE indicator light flashes while driving. I only get three beeps after start-up (usually when I start moving in 1st or Reverse) and nothing more while driving.

Any ideas? I'm still planning on checking grounds, but I really don't want to lose my stereo chasing other problems!

Update II: ABS light is on solid and BRAKE light flashing with occasional warning beeps. It seemed like it was starting to behave last night, but today it was beeping at me more. The beep started seeming like it was corresponding to my hitting speed bumps in the neighborhood at or below the posted speed (20mph). Once out of the neighborhood it was random and I couldn't correlate the beeping to anything in particular. Maybe acceleration or shifting.

I haven't had time to look into the grounds yet. Anybody got any ideas??

Clean your brakes well, might just be a wheel sensor. Mine acts up every now and again, it beeps and flashes, and VagCom shows everythink OK. brakes are good, fluid is good, I guess when it beeps it's time for the carwash!

Brakes

Yardstick said:

Update II: ABS light is on solid and BRAKE light flashing with occasional warning beeps. It seemed like it was starting to behave last night, but today it was beeping at me more. The beep started seeming like it was corresponding to my hitting speed bumps in the neighborhood at or below the posted speed (20mph). Once out of the neighborhood it was random and I couldn't correlate the beeping to anything in particular. Maybe acceleration or shifting.

I haven't had time to look into the grounds yet. Anybody got any ideas??

Click to expand...

I checked my front brakes and they looked just fine. I couldn't get the light to quit coming on. I took it to a repair shop and he pointed out to me the although the outside of the brake pads looked good the inside where the sensor was were worn down to metal. Replaced the brakes on the front and all was well.

Sounds like the caliper wasnt sliding to equalize pressure on both sides of the rotor. Hopefully the shop lubricated everything.

does this car have the Bosch 5.3 ABS?

I'm not sure what system of ABS is on the car. I'm pretty sure it doesn't have ESP (I think that's what the option was). Is there a recall or something specific to the Bosch 5.3 system? How would I tell if I have it?

The car was nice to me again this morning. It only beeped after I got it out of the driveway and didn't beep on the rest of the drive. I checked too, this isn't the friendly, "hey dumba$$, you're driving with the parking brake on" beep, it's the "HEY, FOOKTARD, SOMETHING IS TERRIBLY WRONG" beep.

The bosch 5.3 has had A LOT of problems, one of the solder joints inside comes loose and the stealership tries to sell you a new one for a couple grand, or you can get it rebuilt for like 300 I believe. Or, if youre reall adventerous, you can do this, http://www.passatworld.com/forums/showthread.php?t=198897 . I did it on my 98 audi a4, and it works like a charm now!

I'm wondering if someone might have welded on my car with the module plugged in. I saw a warning somewhere about unplugging the ABS module specifically if you're going to do any welding on the car. It is a "restored title" car, so who knows. With the ABS fuse out it only beeps after the key is in the on position for ~30 seconds or a minute or something. That's not as bad as driving down the road and having it beep over-and-over-and-over... And the brakes feel and work fine without ABS enabled.

I wonder if I can take just the electronic unit off while the rest of the ABS block remains connected and in the car. I'd open it up and poke around if there's a chance it's just a bad connection and I don't have to completely disable the car. I've done a LOT of electronics work... Thanks for the tip!

ABS & Brake Light

Had similar issues, so I read on and flush the ABS module by having the wife pump and me bleed. We did this for all four wheels. However I believe the real culprit was the positive lead off the battery to the fuse box above the battery. This screw or contact was loose. Recommend you remove this and wire brush both sides, then replace and tighten. Worth a try. So far this week (3 days), no ABS or Brake light alarms.