no speedometer, esp light, abs light, code P0501

[like a B6]

As I was turning onto mullholland drive yesterday afternoon, my dashboard went crazy with warning lights. The abs light, esp light, then later the check engine light which reads code P0501. The speedometer isn't working, but the mileage is getting higher. The code reads as the vehicle speed sensor, but have read that it could be the abs control module too. I would like to fix this as soon as possible, is there some way to test what I need to replace before doing the work?

[like a B6]

Also, It might be worth mentioning... it isn't always immediate, the warning lights are sometimes on when it starts, other times it will drive a few miles before the lights come on. There is also a squeaking sound as I drive that I've never noticed before.

[imnuts]

Did you try searching for any info about the stored code? Looks like it's a bad speed sensor (or wiring). I feel like this is semi-common, and the symptoms you describe are similar to what I've seen with others that have had the same problem.

[like a B6]

I've definitely searched. There were 4 or 5 posts about it, but they didn't really have any good information. The code definitions are pretty much the only actual info I found.

16885
P0501

Vehicle Speed Sensor Range/Performance

I don't know if it's a dedicated sensor, or if it is part of the abs wheel speed sensors. I can't even find any info on where the sensor is even located to check it. I'm hoping it's just a loose connection.

[a4darkness]

Do you have aftermarket HIDs and if so where is the the ballast on the driver's side mounted?

[like a B6]

Do you have aftermarket HIDs and if so where is the the ballast on the driver's side mounted?

It has the stock xenon lights.

[a4darkness]

Bummer. Was hoping you mounted a ballast right next to the ABS module as that'll make everything go nutty.

Here's a link to a DIY for the ABS module on the B5, should get you started.
http://www.audiworld.com/tech/elec116.shtml

[like a B6]

After reading that, I'm more sure that its the vehicle speed sensor. My red "brake" warning light isn't coming on like described. And it didn't mention the speedometer not working as part of the symptoms.

My question now... where is the vehicle speed sensor located? and what is the part number?

[a4darkness]

Oh, I just naturally assumed you had a bright angry ABS light staring you down.

Here ya go...
http://www.audizine.com/forum/showth...29-Replacement

Once you get her running right again, go take a hot lap around the backside of PV to San Pedro for me. I miss that drive.

[like a B6]

Oh, I just naturally assumed you had a bright angry ABS light staring you down.

Here ya go...
http://www.audizine.com/forum/showth...29-Replacement

Once you get her running right again, go take a hot lap around the backside of PV to San Pedro for me. I miss that drive.

I came across this, but its for the engine speed sensor, not the vehicle speed sensor.

That drive is amazing! I miss having to do it every day. Used to do it in my honda crx all the time, I have to take the Audi again soon.

[a4darkness]

I should just stop posting and call it a nite. Been doing HW literally all day long, apparently my brain is pretty toast.

There's a nice large shot of it here in my suspension DIY, post #2 (ad post #6 for the rear)
http://www.audizine.com/forum/showth...ipload-of-Pics

More info here.
http://www.audi-forums.com/b6-forum/...ed-sensor.html

I'm firing myself from teh interwebs for the evening.

[jpatino]

I am having the same problem. Have you figured out what it was?

[jonsaudi]

Same problem here. I don't have the ESP light on but I do have the ABS and CEL come on sporadically. Also, I can feel the ABS pulsate sporadically on normal braking conditions as well. Anybody got an idea??

[DiertyEuroSpec]

I am having the exact same issues the OP was having. I replaced the drivers side speed sensor which my CEL indicated was the issue, however no dice...same ESP ABS and no speedo. I do have after market HID's which have been on the car longer than I've owned it.

^^^ I can also feel the brake pedal pulsate very lightly for about 1 sec just before the lights come on. I'm wondering which part of the ABS is the problem

[DiertyEuroSpec]

Anybody out there successfully find and a solution to the problems described here? So many different possibilities when dealing with the ABS system

[old guy]

^^^ I can also feel the brake pedal pulsate very lightly for about 1 sec just before the lights come on. I'm wondering which part of the ABS is the problem

It's been pretty well documented that aftermarket HIDs can emit EMF's that interfere with the ABS module. I know you stated that you have had yours for several years with no issues but it is very possible that the ballast is starting to break down and the emitted EMF is changing. First thing I would suggest is to either relocate or shield the drivers side ballast/ignitor from the ABS unit and see if it makes a difference.

[DiertyEuroSpec]

Interesting...I will look into relocating as well as seeing if I can fabricate some kind of shield. I don't know what kind of materials I have on hand but most likely have some aluminum and thin sheet metal. Will let everyone know of the outcome. Fingers crossed this is causing the issue. Thanks OG

[VisionPaintball]

No updates?

[VisionPaintball]

Can't it be this sensor?

http://www.ecstuning.com/Audi-B6_A4-.../ABS/ES440908/

[A4OrlandoB6]

The other day on a 600mi trip, my cruise control suddenly shut off and then I tried to put it back on, it would turn back off in less than a second. Shortly after, my speedometer and RPM gauges fell all the way to 0, and would jump erratically. Fuel and temp gauges stayed normal. Then, when i thought it couldn't get any more weird, my ESP light came on, followed by my Airbag light( which would come on for a few seconds, then turn off, then come back on.) Also, my check engine light(which is always on for SAI) turned OFF. lol? FWIW, no after market lights here. OEM S4 bixenons

This was about 2 hours into the drive. It had rained like crazy that whole day prior to leaving. When all of this started happening and continued for 15 miles or so, I made a u-turn on the toll highway. As soon as I made the turn, everything stopped acting up. So I drove another 10 miles or so.. everything was good. Turned back around and continued on my journey. Never another problem.

Im pretty sure I may have had some water in my ECU box.

[jonsaudi]

Quick UPDATE:

Ok. I had the module rebuilt. All's well. Turns out the old speed sensor wasn't the problem, but the module was malfunctioning therefore sending a faulty sensor signal. Here's my thread: http://www.audizine.com/forum/showth...cing-sensor%29

[DiertyEuroSpec]

Jon, your experience scares me now as I've already tossed out the original speed sensor and have the Vemo unit. However it does work sporadically... actually this morning I left my car outside the garage overnight and had no ABS ESP for about an hour. Seems the lights don't come on as quickly when its cold outside. My next move is going to be the ABS module rebuild, and I'm praying after rebuilt it picks up the new speed sensor I installed.

[jonsaudi]

I hope it works out for you too. Consider CheapABS.com for the rebuild. Great and fast service.

Jon, your experience scares me now as I've already tossed out the original speed sensor and have the Vemo unit. However it does work sporadically... actually this morning I left my car outside the garage overnight and had no ABS ESP for about an hour. Seems the lights don't come on as quickly when its cold outside. My next move is going to be the ABS module rebuild, and I'm praying after rebuilt it picks up the new speed sensor I installed.

[VisionPaintball]

Just had my abs module repaired, fixed my issues as well.

[DiertyEuroSpec]

Just had my abs module repaired, fixed my issues as well.

Same here I just put it back in today...fingers crossed it holds up!!

BTW k0mpresed did my fix..great guy to deal with

[VisionPaintball]

Same here I just put it back in today...fingers crossed it holds up!!

BTW k0mpresed did my fix..great guy to deal with

He did mine as well!

Audi sure makes some interesting cars, and by interesting I mean crappy.

[VisionPaintball]

I am having the issues again. Hate this car.

[VisionPaintball]

Can you use another module from another car?

[VisionPaintball]

From cheap abs.com-

" On Bosch 5.7 modules, we typically replace between 10 and 12 parts; however, in some cases these modules are not repairable due to an internal memory fault. If yours has this kind of failure, you will be issued a refund less shipping."

I think mine is not repairable. This stinks.

[diagnosticator]

I am having the issues again. Hate this car.

You think your A4 is "crappy", and you hate your car. Your A4 can sense this, and is reacting according to your attitude. This is directly related to your car karma, and the Zen of machines.

[DiertyEuroSpec]

Just an update to my situation... I had the ABS module rebuilt by forum member k0mpresed about a year ago, and all has been well with the ABS system. I had both ABS and ESP lights light up and no speedo until the ABS module fix.

[ridenickel9]

Yep used ABS module saves me too after I replaced the front left ABS sensor. Coding it today using ross tech. Been driving non coded with perfect speedo just abs esp and flashing brake light for past week waiting on my software. Good luck !

[blitz2190]

Yep used ABS module saves me too after I replaced the front left ABS sensor. Coding it today using ross tech. Been driving non coded with perfect speedo just abs esp and flashing brake light for past week waiting on my software. Good luck !

He probably figured it out 2 years ago when he posted it.

[forevraudi]