DIY Speedo Calibration

[Da~da~da]

I did a quick check on my speedo going to work this morning. I have not done the mod yet but probably will. It has to be a vag.com thing, cause my difference between the 2 is not consistent.

Speedo Real Difference
10 8 2
20 18 2
30 27 3
40 36 4
50 45 5
60 55 5
70 64 6
80 73 7

Cmon VW. ***

Hear Hear My numbers are spot on with yours using GPS and climatronic compared against actual (gps and climatronic dead on)

 

[bondtimbond]

Works great!!!

I finally tried this procedure and it works just fine. It is easy to do, even without the photos that are missing from the original post. My speedometer now reads 1 mph low at 20 and 30, then reads right on at 40 and 50, then reads about 1 mph high at 60 - 80. That is not bad at all, probably now more accurate than any other car I have. I am so far happy with the results. I recommend this to anyone with this complaint.

 

[f1wanabe]

Just did your fix and got within .5mph according to a radar gun on Main St. at 30-40-50 MPH. 50 was tough since it is a 35mph steet! I will check for higher speed accuracy the next time I go thru a construction zone.

This was amazingly simple. I would have resisted trying this type of repair, but your instrctions were spot on.

Note to others:
-The plastic covers have 2 clips (one on right, one on left) that slip into a hole and are kept in by spring tension. Try to compress them from underneath. I did not and one clip chipped the black plastic surround just above the fastener. Luckily it is mostly hidden by the removable cover.
-Do not apply too much force on the needle to start. Mine "broke loose" a little too far past "0", so I had to move it back.
-The speedo needle sits below "0" at rest, but jumps up quickly once you are moving.

Thanks for the quick fix!

 

[rotarykid]

Before the days of GPS I used to do this by timing myself between mile markers . It was a pretty accurate way to do this , recalibrate speedo's to read a more accurate speed .

Many of us have been doing this for all of our driving life , I've even done it to a few motorcycle speedo's over the close to 30 years of me doing this .

Pulling the needle loose and moving it the amount of speedo error that you have determined is a fairly simple procedure . It's much more likely to be harder to pull the cluster apart than to fix the actual speed o error .

 

[doonboggle]

Pictures ??

Wonder where the pictures that were apparently posted at the beginning went to ?? Sure would be useful.

 

[Lightflyer1]

Have you tried a PM to the OP?

 

[WHIFF]

A picture being worth 1000 words, this would sure help those of us with this frustrating speedo problem. I haven't really been able to gauge the odometer. Almost everyone here says it's spot on, but the speedo is off by that annoying 3-7 mph, depending on how fast you are travelling.
If I get some courage, I'll do the deed and try to get some pictures along the way. I'd really rather have the benefit of the pics here for me to see when I try to bust open my gauge cluster

 

[icecap]

Speedo error

A picture being worth 1000 words, this would sure help those of us with this frustrating speedo problem. I haven't really been able to gauge the odometer. Almost everyone here says it's spot on, but the speedo is off by that annoying 3-7 mph, depending on how fast you are travelling.
If I get some courage, I'll do the deed and try to get some pictures along the way. I'd really rather have the benefit of the pics here for me to see when I try to bust open my gauge cluster

Hi whiff,
Look back in the TDI 101 forum for speedo error and you will find my post of a VW TSB with instructions for dealers to recode all of their speedometers on 2007 new vehicles in their inventories. I did the recode on my 2006 jetta and it corrected the speedo from 7% fast to less than 2% fast. I haven't checked the odometer yet but know it was out before as well since it always ticked over short of measured Km markers by at least 5 car lengths. Incidentaly, the vag-com vehicle stats of my 2006 instrument cluster read the same stats as in the 2007 TSB.

 

[Tim Birney]

If your Odometer was 5 car lengths off on the first mile, and remained 5 car lengths off on subsequent mile markers, then it was dead on.
If your OD was incrementing the variation, then, yes, it was probably off.
Comparing my OD to 21 Mile Markers I noticed that it was right on for the total of all 21 markers, but there were sporadic misses throughout the various markers in between.
The only way to tell is with a GPS, comparing it to your actual OD.
I have yet to see a MKV that had an Odometer that was not "Dead On" from the factory. The Dealership fix, courtesy of VW, will maladjust the OD.

 

[WHIFF]

So it sounds to me like the best fix is the DIY needle tweak at the top of this thread, no? I'm all over it next weekend.

 

[volks1]

easy does it!

Just a note to keep in mind here:
If you are about to pull off the needle and put it back on, or just click the needle back, the step motor that runs it may break.
A new cluster retails for $695 CDN. + reprogramming.

Also, swapping clusters with one previously used on another car is not just a simple reprogram, even if the part numbers are the same. REMEMBER THE IMMOBILIZER IS IN THE CLUSTER.
Sometimes a cluster from another car cannot be reprogrammed to a new car.

I retrospect I'd open the cluster as described (very easy) and dial the speedo needle counterclockwise about 3/16 to 1/4". The accuracy will be 100% at 120km/h, 3km/h pessimistic at 50km/h, 1km/h optimistic at 140km/h. The needle will sit idle below 0km/h.

All in the name of speedo accuracy...

 

[Turbine Suburban]

I find the one in the 09 dead on. Did I get lucky, or has this improved?

 

[fgbrault]

I find the one in the 09 dead on. Did I get lucky, or has this improved?

Improved. Based on a previous thread and my own experience the 2009 appears to range from dead-on to +/- 1MPH. Mine is dead on or within 1/2 MPH based on my GPS and various street radars. If anything it is a tad under. My 2007 BMW 328XI was about 8% fast - a real pain.

 

[icecap]

I find the one in the 09 dead on. Did I get lucky, or has this improved?

If you follow the threads regarding A5 speedo error you will find that the problem was resolved with the 2007 model year as VW issued a TSB instructing all dealers to recode the speedos of all 2007's in their inventories. From that point on all vehicles left the factory with the new correct coding. A further TSB was issued permitting the recode to be done on all A5's. The threads resulted in much controversy and contention regarding skewing of the odometer, sky is falling and wheels will fall off. I corrected mine as soon as I saw the Dealer TSB and mine is accurate compared to my GPS within the width of the needle now.

 

[securityguy]

I have an in-dash Garmin GPS that provides mph on the main screen and I have looked on many occassions and noticed that I am always within 0.5-1.0 mph of the speed registering on the speedo. Therefore, I would surmise that this issue of innacuracy in the 2009-2010 has been resolved.

 

[adjat84th]

70mph indicated = 72mph GPS for me. 16" stock wheels

 

[hid3]

Reaading this thread makes me confused. In some other thread it was stated just to change the 'Distance impulse number' In Instruments coding with VCDS because that mod doesn't screw the odometer.

By making this adjustment, will I screw my odo or not?

In other words, which procedure should I take to calibrate my speedo correctly and still have a dead-accurate odometer reading? Thanks.

 

[andmoon]

Thanks!
When I bought my 06 tdi new 70K miles ago the odo was spot on but the speedo read ~ 5 mph high at 70 mph. The dealer reprogrammed something and the speedo read 3 mph high at 70 but the odo was reading 2.5% low. I just did this and of course I didn't follow the 'leave the glass off' part...now the speedo reads 70 at an actual 71.6 mph. When i find the energy I will do it again and click the needle one notch up.

 

[Lightflyer1]

Last I heard there was no real fix. Changing using VCDS affects the odometer. Moving the needle will put you off at lower speeds (think school zones). I used to use the "secret" buttons to display true speed on mine (Climatronic).

 

[hid3]

Last I heard there was no real fix. Changing using VCDS affects the odometer. Moving the needle will put you off at lower speeds (think school zones). I used to use the "secret" buttons to display true speed on mine (Climatronic).

That's sad. I don't have Climatronic OTOH Looks like I'll need to observe speed limits and never drive it too fast

 

[Rob71zilla]

I just did this and it worked well I'm happy with it but I seemed to have lost the "cover" that goes behind that turn signal arrows on the front glass piece. I don't remember seeing anything fall off and they aren't anywhere in the car or around it but there was definitely something there. Does anyone know if I can get replacement parts? I'll probably just put a black piece of paper behind the arrows for now and hope the lights still show through enough.

 

[ZiggyTheHamster]

I just want to say this, because apparently everyone thinks the opposite.

Never consider your GPS speed to be absolutely accurate. It isn't. The US government introduces a bit of error into the GPS system for civilians. This is so a civilian can't use GPS to direct a weapon at a specific target. The error is around 10 meters (notice next time you exit how your GPS might not recognize immediately that you left the highway), which is more than accurate enough for most things, but since the error is randomized, you can't count on your GPS calculating your speed accurately.

If your speedo says 70 MPH and your GPS says 75 MPH, you're probably going 71-72 MPH. If your speedo says 70 MPH and your GPS says 72 MPH, you're probably going 70 MPH.

If you can't use GPS to set your speedo correctly, what can you use? Don't use radar, because it's also prone to error (and it gets exponentially worse the further you get away from the radar beam, since the beam spreads.. a radar beam is only good for around 4 lanes of traffic, and after that it's the size of a car or two and not accurate). I think that a dyno might be able to measure the speed your wheels are actually traveling, and THAT is what I'd use to tune my speedo. If that's not an option, leave it alone.

 

[spangenberg]

Just did this today. Mine was pretty far off (about 7mph) but i nudged the needle and it is almost spot on. But upon putting the cluster back into place, and turn the car on. the ESP light, steering wheel light, and the airbag light come on. I did NOT undo the battery terminal at all, but in reading later on it seems that i should have.

Any ideas on how to reset these?

 

[Lightflyer1]

VCDS is the tool needed. Remember if you reset the needle it is now only correct at one speed. Anything faster or slower than that will be off.

 

[barshnik]

I just want to say this, because apparently everyone thinks the opposite.

Never consider your GPS speed to be absolutely accurate. It isn't. The US government introduces a bit of error into the GPS system for civilians. This is so a civilian can't use GPS to direct a weapon at a specific target. The error is around 10 meters (notice next time you exit how your GPS might not recognize immediately that you left the highway), which is more than accurate enough for most things, but since the error is randomized, you can't count on your GPS calculating your speed accurately.

The US Dept. of Defense did away with SA (selective availability) way back in May of 2000. The military can use a different frequency (L2 instead of L1) which is less prone to other sources of error (atmospheric, orbital,geometry shading, etc), but the civilian L1 is not intentionally degraded in any way. A good quality GPS with WAAS or DGPS will get you within 3 meters or better.

The cheapest Walmart GPS will give a more accurate reading (given good sat coverage at a particular time) than your car's speedo or odo.

John F

 

[JDub8]

^^^
Yes GPS accuracy has to do with the quality and type of the users equipment, not the govt's restrictions.

Consumer GPS is great for calculating speeds, and if you want to use it for targeting purposes look into high end systems like they use on the darpa grand challenge.

 

[rotarykid]

I just want to say this, because apparently everyone thinks the opposite.

Never consider your GPS speed to be absolutely accurate. It isn't. The US government introduces a bit of error into the GPS system for civilians. This is so a civilian can't use GPS to direct a weapon at a specific target. The error is around 10 meters (notice next time you exit how your GPS might not recognize immediately that you left the highway), which is more than accurate enough for most things, but since the error is randomized, you can't count on your GPS calculating your speed accurately.

If your speedo says 70 MPH and your GPS says 75 MPH, you're probably going 71-72 MPH. If your speedo says 70 MPH and your GPS says 72 MPH, you're probably going 70 MPH.

If you can't use GPS to set your speedo correctly, what can you use? Don't use radar, because it's also prone to error (and it gets exponentially worse the further you get away from the radar beam, since the beam spreads.. a radar beam is only good for around 4 lanes of traffic, and after that it's the size of a car or two and not accurate). I think that a dyno might be able to measure the speed your wheels are actually traveling, and THAT is what I'd use to tune my speedo. If that's not an option, leave it alone.

I have four Garmin Nuvi's that I hook up when I'm driving around. A 255WT and 750 I use as the speedo's , a 1300T and a 1450LMT that I use for the eco driving functions, elevation and maps. I also have a friend with a 1350 that I have played with. You would never believe how cheaply these things can be purchased for off of craigslist. Pretty much any Nuvi model can be purchased for $25-50 from people that got them as presents and now need money.

I have hooked all of them up at the same time in the same car while driving before to compare accuracy. Here is what I have found, the speedo function on all seem to agree 100 % of the time, so speed readings are very reliable. While the elevation readings can be off by as little as a few ft or as much as 300 ft from one receiver to the other.

My 9500ix radar/lasor detector has gps and can be set to give speed readings on the display when you pickup a radar or lasor signal. Escort claims the speed readings displayed are 100 % accurate. The speedo readings it gives are dead on in aggreement with what the 5 Nuvi's give, observed.

So I would trust them for speed readings as being dead on, but not so much for an accurate reading of elevation. If they programed a error into consumer units it is apparently in the elevation readings.

 

[ZiggyTheHamster]

As I mentioned in a previous thread, and proceed to stick foot in mouth again, I didn't realize that the selective availability was turned off a long time ago.

So in that case, by all means go with your GPS. But I wouldn't turn the needle by hand unless it was the needle that was off -- doesn't the ECU report true speed? If that was spot-on, then fix the needle. Otherwise fix the true speed and then fix the needle if needed.

 

[Lightflyer1]

There is no true fix. Just drive a few mph faster if you like.

 

[spangenberg]

The ESP and the other light went off, but the airbag light is still on. I heard somewhere that i can disconnect the battery terminals for 24 hours and that might reset everything?

Would that work? Or do I really need a VAG-COM to fix it?