DIY Fix for broken Speedometer & VSS Implausible Signal

[angry12v]

I bought an A4 with a non-working speedometer and odometer.

Scanned the codes and found:

16885 - Vehicle Speed Sensor: Implausible Signal

I replaced the sensor, but the speedometer still didn't work.

I performed an output test on the cluster with VAG-COM and found that all the gauges were working properly... so it wasn't the cluster.

Here's how I fixed it... I hope this helps anybody who is struggling with this issue in the future.


This is the part that you need to replace, its a magnetic ring inside of the differential case

Part # 012-409-182-C



First, remove the left front wheel.
Remove the axle.
Drain the transmission fluid.
I think these are all pretty self explanatory.

Next, remove the axle flange. It just pulls straight out of the transmission. The easiest way to do this is with two long bolts with the same thread as the inner cv bolts (8x1.25). Make sure they are threaded their entire length. Thread them into the holes like you would the cv bolts, across from each other and tighten them alternating between the two, this will push against the diff case and pull the flange out evenly.



Now you'll need to remove the side cover from the diff case. First unplug the VSS, remove it, and push the plug out of the way. Now there are 9 Torx bolts to remove. The one on the far right is the most difficult because of the tranny mount bracket. They are all torqued pretty tight, I had to use a breaker bar on them.



Here is the cover removed



As soon as I removed the cover, the shattered pieces of the ring came falling out and my suspicions were confirmed



A few pieces of the old with the new



Here is the differential. Notice the last little piece of the ring still clinging on at about the 10 o'clock position



At this point I took the opportunity to replace the output shaft seal. Simply press out and press in



Now it's time to install the new ring, it just snaps onto the shaft



A closer look



Then it's just a matter of putting it back together in reverse. I added a thin coat of grey RTV (gasket maker) around the edge of the cover to make sure there weren't any leaks

New axle installed (with new inner CV bolts & new axle bolt), VSS replaced, and hose in the fill hole for new tranny fluid. I used 3 quarts of Mobil 1 75W-90, which was the best thing I could find locally.

CV grease everywhere... oops



So my winter beater now has a working speedometer, and as an added bonus the transmission shifts much smoother with the new fluid.



I hope somebody finds this helpful, because when I was looking for a solution I couldn't find much info on how to fix it.

Cheers

[fred2ka4]

Nice write up and I think I have the exact same problem as I have replaced the tranny speed sensor and the vacuum pump with no effect. Did you purchase the magnetic sensor from your local dealer?

[angry12v]

Yup you can get it at a dealer or anyone that sells OEM parts. Chances are they won't have it in stock and will have to order it

[fred2ka4]

Yup you can get it at a dealer or anyone that sells OEM parts. Chances are they won't have it in stock and will have to order it

Thanks because my next step was to replace the CC module which is tied into the speed sensor as well and I would much rather do this as it is less expensive. When I changed out my center diff with a STaSIS one I upgraded to RedLine synthetic, and I have enough left over as purchased 2 gallons ......

[walky_talky20]

Very nice writeup. Thank you for taking the time to do it. It is appreciated.

[DJ_Snowman]

Yup you can get it at a dealer or anyone that sells OEM parts. Chances are they won't have it in stock and will have to order it

great write up really appreciate all the detailed steps! could you give me the exact part code or name to the magnetic ring? im looking to do the same on my 97 a4 with the exact same problem, im a noob to audis just recently bought my first one for a daily driver.. so id appreciate any help you could give me, Thanks!!

oh by the way, is there any way that this problem could be because a faulty instrument cluster, mine lights up completely! odometer reads out everything works, simply the odometer doesn't go passed the miles it has and the speedo is ALWAYS stuck at zero .. my friend thats a mechanic says he believes its the cluster because he worked on a honda with the same problem and it was the cluster, he specializes in Japanese cars only though so i dont trust his word fully! again thanks for any help man id really appreciate it like i said im a noob to Euros

[chris164935]

Hi, I'm curious how you came to the conclusion that the magnetic ring was the culprit?

[DJ_Snowman]

Nevermind, i changed my VSS today and that fixed my problem! glad to report i didnt have to buy any more parts! 22 dollars for a new sensor, an hour and a half of labor (that sensor is hard to get to in the position its at, specially with the metal heat guard above it!) and speedo and odometer are back to normal!!

[fred2ka4]

I'm going to replace mine as soon as I get the sensor as I have replaced everything else. I have the same issues, no mph or miles recorded on the trip meter. Also the doors wont lock at 5 mph but I would assume that's because there is not a recorded speed ...........

Could this effect the cruise control as well?

[a4t-qtro]

Just to give a little update , i replaced my magnetic ring about 5 weeks ago because my speedometer wasnt working. The ring was in really good shape everything was looking good but i decided to change it anyways since it was around 35$ CAN.I've put new audi tranny oil and the speedo now works good since then , i did 5000 kilometers and its never stopped working. Thakns for the diy.

[keztoora]

hi,for some resons i could not open them pictures! thanks

[mschultz84]

I can't see the pictures either. Does anyone have a part number for this ring? I can't find one anywhere, and the parts guy at my local VW dealer cant look it up for me since a VW dealer can't "Sell" to audi owners per VW/Audi franchise rules, but if I give him a VW/Audi Part number, he can sell it to me off the P/N. should be the same part on a Passat, though.

[ZimbutheMonkey]

Aaaarrrgh! I want to see those pics in the worst way. I'm putting a V8 Audi torsen diff in and I'm trying to figure out how that ring is going to fit. Please get those pics back up.

[angry12v]

Pics should be back up now, please let me know if you still can't see them

[ZimbutheMonkey]

It's all good, thanks man!

[mschultz84]

Thanks for getting the pics back up! I called my local VW dealer and they can get the part (012409182C) to me for $34US. How much total time did it take you? I'm wondering if I can do it in an evening after work, or if I need to set aside the whole weekend. Thanks!

[ZimbutheMonkey]

As long as you're moderately experienced and don't have a fused pinch bolt I'd say an evening after work. However things can and do go sideways so just make sure you have a backup plan.

[JB5]

just need to troubleshoot the issue im having with my speedometer. mine does record the miles driven, sometimes it works and sometimes it stops working. I'm not exactly sure what causes it not to function. will this be something that you think might be related to the magnetic ring? from what i read from different posts, some will not even record the millage run.
at first i thought that it could have been my speed sensor, however if this fails my car would not even start.

thanks for your input.

[JB5]

can anyone confirm if the Climate Control will detect the RPM if the magnetic ring is broken? this morning my cuslter worked on my way to the tag office. i leave the tag office and its not working. however the climate control does show the RPM.

thanks.

[serek]

angry12v.. I have just registered on the forum to say thanks.. for both idea and great manual. Your manual just helped to fix A4 driven in Ireland.

After replacing the ring speedo works again, milage is clocking and fuel gauge behaves better.

In my case ring did not break apart, but the metal clips, which stops the ring from rotating freely snaped.. I found two of them sticked to the ring itself on the outside.. good thing that the ring is magnetic.. otherwise those metal pieces could be anywhere in the gear box.

As for the manual there was just one little thing that wasn't mentioned.. one of the 9 torx bolts holding diff cover wasn't accessible without taking off the transmssion bracket (bracket overlap over the bolt). Lifted transmission slightly on the jack to remove tension, removed 4 bolts and the bracket could move enough to uncover the torx bolt.

I can clearly see on your pictures that bracket is not on the way, but it is in my model.. maybe quattro +avant + right hand side steering wheel makes enough difference.

Again huge thanks!

Regards,
Sergiusz

[Ease8080]

How exactly do i test output performance on my cluster? I'm pretty good with a multi-meter, but this is the first time I've heard of a vag-com. I believe my problem is the magnetic ring too, but a mechanic told me that it's my odometer but i have a feeling that's not the case. Please reply. I really appreciate it. Thanks.

[metafizz]

Thank you for your DIY, worked a treat, just got mine working again!!! After changing the VSS to no avail, and checking the cluster with VAG-COM found out it was working, changed out the magnetic ring and voila, it works! Can't thank you enough.

[angry12v]

I'm really glad this thread is still helping people over 2 years later!

I've just run into this issue with the A4 that I currently own and I had to come back to my own thread to remember how I did it!

[seanj130]

You could have not put any miles on your B5!! I had a similar problem with the speedo not working, and it ended up being the metal sensor that went in the top of the transmission.

[1986nate]

Thanks for this. My original trans had this fail and figured this was the cause after I swapped in the speed sensor from the spare trans. I later swapped it out as I had no reverse as well. Recently, this transmission has had intermittent oddball speedo readings. When I drop it out to do the clutch I'll likely go in there and replace it even if swapping the sensor out takes care of it. Seems that it's fairly common to fail and easier to change with the transmission out anyway. :)

[Shhmaudi]

A++ Excellent write up! This helped me too!

[Loubylou]

Write up spot on, sorted my A4 for a fraction of the cost. Can't thank you enough! Xx

[Trabeate]

Pretty sure I need to replace mine too. Curious if anyone know if Audi/vw/Porsche are interchangeable. Part numbers are the same. I have found a few on different sites. Porsche one is $10-20 cheaper.

[wolfe2118]

Pretty sure I need to replace mine too. Curious if anyone know if Audi/vw/Porsche are interchangeable. Part numbers are the same. I have found a few on different sites. Porsche one is $10-20 cheaper.

I am using the Porsche one now. It is the same.

[Trabeate]

OK that's good. I just finished ordering one. Might take a few days longer than Audi one though.

[mauromj]

I just finished up my 5 speed swap and my odometer and speedometer are not working since. I tried another speed sensor I had and nothing. Glad I found this thread! Will be ordering the magnetic ring tonight.

[jschuholz]

couple general comments - obviously when speedometer is 0 - several problems could exist.
1. vss is broke, 2. connector connection is bad to vss, 3. magnetic ring is broke, 4. fuse is blown, 5. cluster is bad.
Isn't it possible oil is contaminated to the point that vss can't get a good pickup from magnetic ring ???

If magnetic ring is broke - don't think this would be intermittent problem. cluster is bad - shouldn't be intermittent. fuse is blown - can't be intermittent.

be nice if a diagnostic flowchart was made to pinpoint the exact problem. I have intermittent speedometer (either on or zero). replaced vss (no help). cleaned old vss and connectors - worked for 10 miles. oil looked fairly dirty when replacing vss. any comments on this problem ? thanks

[fR3ZNO]

Would it be safe to assume that this DIY is the same for an automatic? Is there any way to check the ring without pulling the cover off?

[Toonttm]

I just had the speedo & rev counter stop working and also the left hand front indicator. Turns out it was the battery. I had accidentally left the key on and drained it. I was only able to charge it for 8ish hours before using the car. When I got home and charged the battery some more and everything (including the indicator) worked.

[ShivasRegal]

Cant see the pictures to this original post. Can anyone Help?

[rodgertherabit]

I had a similar issue. I swapped to a different ecu and it was reading speed via VagCom (measuring blocks) but it was incorrect.

Ive bypassed it for now. but the cruise doesnt work and its annoying. Once the trans goes in for rebuild ill replace this part.

[kyledavidd93]

i am purchasing a 03 audi a4 3.0 quattro on sunday and he told me the only things wrong with it is the speedo does nto working and the check engine light is on .. i alrady had the obd2 scanned and the code came back just for evap. he said all of the rest of the cluster works just not the speedo . after reading all these known issues with the speedo on the a4 im kind of getting worried . would you think it is still agood buy ? he is only wanting 2k for the car and it has160k in almost perfect condition

[nemick]

Still sounds like a decent buy to me

[2old2turbo]

2003 3 liter 6 sp manual transmission (Sport Package) does not have a VSS on the left side of the front differential.

[s4u2nv]

Which fuse may be blown out for the speedometer to stop working? I keep seeing people ask about the fuse. Also your photos are not showing. Could you email them to me?