Alright, so many of you probably have gone through inspections right?
WELL, putting it out there, GERMAN inspections are a million times worse. I keep getting failed for my ABS light staying on.

Background on my VAG/OBD II port, it is in the rear middle ashtray behind the center arm rest. Not where I have ever seen it before, then again, this is a European Audi. Also, it's a 99 2.5TDI, so any other 2.5 owners, input would be appreciated if this is the same for yours as well. To the Dealership! I took her to a local Audi dealer 12km away (luckily the guy spoke spoke some broken english). We hooked it up to VAG and this is where a few of my questions start.

1.) The VAG connecter he was using was wireless, I have NEVER seen VAG hooked up like this before, so this could be part of the problem.

2.) His computer/VAG couldn't communicate with my ECU/ABS, nothing at all..See question 1. The other question is, how often does the wiring between the On board diagnostic and the ECU go bad? All lights on Instrument panel are good, and On board computer says "OK" when i turn the ignition on.(while i'm waiting for my coil heaters to warm up)

3.) the ABS light turned off for about 20 seconds when he turned over the engine. Then turned back on again. still no communication with VAG.

4.) brakes were just replaced, could be the sensor was not replaced/plugged in.. haven't had time to take it to the lift on post yet. The battery was recently replaced before I bought the car, so no idea if the light was on then or not. The car was a REPO, so It was bought from a liaison from the bank that owned it. I could call the guy, but I wasn't given a warranty, so it's my problem now.

5.) I could unplug the battery overnight, and see if that fixes the problem, If that doesn't work, then here is my last resort.

(last resort), take off the instrument cluster, and just take out the F@cking light. and see where that gets me.. and then diagnose the problem before my Temp Plates run out in a week.

Any hints, suggestions, personal experience would be appreciated. I'm not new to the world of AUDI, but US inspection could care less about the lights. at least the garage i took it to.

The Inspection guy here on post won't cut me a break, or help me at all, this guy just looks at the car for 5 minutes, and either passes/fails the car. *NOTE* this is how f@cking (DoD)civilians treat US soldiers.

Trying the battery tonight, so i will repost on that tomorrow on that theory.

 

Wireless vag? Never heard of
Also, can't take the abs lights out the cluster because they are smd led.
Usually the abs is accompanied by the brake light and they flash to tell you a better idea of the problem. You can always just pop the sensors out and look at them, they will be noticeably bad. If all 4 check out its probably the module.

 

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The radio and/or abs module can cause communication issues. Some people have to disconnect their abs module to allow communication if their abs module is having problems and the radio if it is aftermarket.

This explains the radio: Ross-Tech: VCDS: Afterrmarket Radio Problem

And they do make wireless scan tools, including vag:

VAD Mobile Products

 

SMD LEDS? Surface mounted LED lights were never implemented on a 99 B5.. They still used bulbs at that point. the back of the cluster has sockets.
So if one burns out, how do you replace the light? they didn't engineer the cluster to need completely replacing did they?(on the newer Audi's)

Checked front sensor today while she was on the lift, took the compressor to them, aired them out, connects look clean. the rear ones need to have the rotors taken off, and i don't have the time for that today.

I wonder if that would work here in Germany. I did the same thing in PA.. Hell my mechanic didn't even care..Out of sight out of mind.. I might try that if part 2 trials tomorrow don't pan out.

I disconnected the battery, reset the radio(stock concert) and dash computer, but still nothing.. checked all the fuses, the #16 fuse(5AMP) was a blank socket so it has to run through the computer.

I read the article on the radio, but even with the aftermarket i had in my old Audi, the ABS light was on long before i switched out the sound system.

That looks like the tool he used.. But even the mechanic at the shop even said that it's like using a wireless device, he used the new xbox as an example.. wired is going to be faster and more reliable than trying to transmit data through the frequency of the device, Router -> xbox(OBD-II ->laptop). so it can on I'll disconnect the ABS while she's on the lift again. and see what we can do.. but i'm beginning to think that taking the bulb out is the easiest way to fix the problem for now.

At least i was able to find out my rear coilover is cracked a bit, so even more good news.

 

I have two clusters apart right now, my friend is soldering new SMD colors on the board, pain in the ***. The only warning lights to use bulls i believe are the CEl and the brights indicator. The rest are SMD, if i had my cluster i would show you but its not here, ill see if i can get some pics today.

 

I you suspect it is one of the wheel sensors, you can test them with a regular multimeter. It really is just a pickup coil with a magnet. Measure the resistance across the two leads. I can look up the spec later, but if the resistance is not infinite (no connection) you should be good to go on that wheel sensor.

All of the sensors I have replaced visually looked fine, but had an internal fault somewhere.

The rear sensors are easy enough to test. They are right under the back seat. Just lift up the cushion. I haven't had to deal with the fronts on these cars, so I don't know where the plugs are located.

Pulling the bulb won't do any good as they check to see if it lights up with the key in engine off and then that it turns off with the engine running.

 

+1, they started using LEDs earlier than 99, it was somewhere around 97 I think.

Its my understanding that an aftermarket radio doesnt affect the ABS, but affects the communication of diagnostic tools.

 

I saw what you were talking about. SO to change the colors you would have to solder them in.. i believe you when you say its a pain, just getting the cluster apart was a pain in itself!

When i hooked it up to the diagnostic, put the car on the lift and put it in 1st, all the wheels registered speed but the left, it stayed at 1 the whole time. probably replace both front though just in case, but that's a project for a later time.

I believe the voltage is something around 2.5 +/- .5A

see the end project notes for my reply to the light..

That makes sense, the only light bulbs were the parking light, and the middle light on the cluster.
END PROJECT NOTES: 14/1/12

SO it was a wheel sensor. when stopped the right reads speed, when moving, the left doesn't register.

The reason the Audi dealer couldn't communicate is because it was a wireless tool, or it wasn't plugged in all the way(ash tray had to come out to get the plug in)

ABS light is fixed, the redneck PA way. Just used electrical tape to cover where the light shines through on the cluster face.

To answer bshusted response to pulling the light, he only care's if the light is on while the car is running, even if he did as where the light was, i'll just say that either, the car doesn't have ABS, or the LED burnt out. If they light doesn't show, there isn't a problem.

At least its not the ABS module or the system itself, just a pesky wheel sensor. So i'll update if the "fix" worked on monday or tuesday when the inspection place is open on post.

Thanks for the help though and the information.. i would have got the cluster off and done a WTF at the leds, but it helped me think of a way around it.

once i get the plates, i'll be able to do more of the remedial work on her.

 

Well, that's good that you found the problem.

How were you testing the wheel sensors? Was this something through VAG-COM? I've used my multimeter to test the pickup coil for resistance, but you mention testing voltage and then reference a measurement in Amperes. Something doesn't quite add up.

As for the light, I assumed that the German inspection would be much more stringent than here in the states. At least that was what I was given to understand from my friends there. Good to know that the redneck way works in Germany too.