# How is the overall mileage of a MK3 stored?



## Fyler1 (May 28, 2010)

My friend has a 1997 Jetta GLS. He wants to replace the gauge cluster (black with white letters/needles) with the cluster from a special edition (white with black letters and orange needles). If we pop in one from another car, will the mileage read from the cluster going into the vehicle? Or would his current mileage be unchanged? For instance. Let's say his mileage before the cluster swap was 150,000. The cluster going in would have read 156,732 from the vehicle it came from. After we install the new cluster, what would the display read? 

I guess a better question technically would be: "How is the mileage of an MK3 VW stored? Is it stored in the console? or in the computer?" 

Now, to weed out any potential off-topic or unrelated answers, I understand the numbers in the examples are close. But I'm trying to go for some accuracy here. I'd prefer to not hear things like "Well, those numbers are close, why would it matter? Just subtract the difference between the old one and new one" or "With the age of the vehicle, mileage isn't important" or something. Just looking for an answer to a question  Thanks in advance for your help.


----------



## Fyler1 (May 28, 2010)

bump!


----------



## Paladin Rider (Jan 28, 2008)

I'm not 100% sure but I'm gonna say that its stored in the cluster. I've heard of people changing the instrument cluster and the mileage reading was changed to what the installed cluster was


----------



## Fyler1 (May 28, 2010)

Yeah, I've since contacted a dealer, who seemed very reluctant to help me because I didn't need to buy anything, I only had a question. He said that the mileage is "burned" into the gauge cluster from the computer only once, and is then stored in the cluster forevermore. Another question is, is the mileage LCD component able to be taken out of the cluster coming out and installed into the cluster going in? I wonder how difficult that would be if it is even possible. That would not only save us $800 (price for a new one, which I have a hard time believing), but it would help retain correct information! Thanks in advance for the help! :thumbup:


----------



## deletedo1m (Jul 10, 2007)

$800 for a new mkIII cluster??? You can get them from a junkyard for about $10. Also check out the mkIII classified section on here. White faced clusters go for about $50.


----------



## Fyler1 (May 28, 2010)

Yes $800 for a new one... have you read any of this thread? Once the mileage is stored into the cluster, it can no longer be changed. So if I wanted to swap a used white faced cluster into the car, it would read the mileage from the donor... which is what I'm trying to avoid. Anyway, does anyone know if the odometer LCD portion of the cluster can be removed? Maybe de-soldered and disconnected from the original and reconnected and re-soldered into the white faced? Because that would be amazing.


----------



## Eric D (Feb 16, 1999)

Desoldering the odometer won't change your mileage.
The mileage is stored on an eeprom.

The Golf 3 cluster has a small 8 pin eeprom.
Some Golf 3 clusters use a 93c46, 93c56 or 93s56 eeprom, the S version being a secure version with block protection. 93c46 show, the other two are the same size.











Some clusters are as easy as connecting a cable to the OBD port, but these early VW clusters require direct connection to the cluster. This means using an adapter that makes contact with the IC pins, soldering 4 wires to the IC, or desoldering the IC using expensive rework tools or carefully desoldering with a solder wick (risky). You would need an eprom/eeprom program that is compatible with the IC's above and have the software and knowledge to use it.


----------



## tesh0boy (Dec 7, 2009)

damn, look at eric d with the answers...haha. I don't know if they do it anymore, but I have heard in the past that some dealerships for a fee of course, would change the mileage for you if they had the machine to do so, again, as long as you could proove your old mileage and that the car is yours, bla bla blah, all that usual crap. but thats since, been long gone by now


----------



## mafiaman52991 (Jun 29, 2009)

i did this in my old jetta, i took the gauge apart so that i could just change the gauge face, take the needles off and then the faces (youll see they are all held in with what looks like plastic rivets) youll need to glue the new faces on but in the end youll have a different looking gauge cluster with the original miles


----------



## fourthchirpin (Nov 19, 2004)

what you can do is take the chip, and program what ever "mileage" you want. I would guess you need to know how to convert to hexadecimal to do so.


http://www.atmel.com/dyn/resources/prod_documents/doc5140.pdf


----------



## Stealthpro411 (Jul 31, 2004)

The mileage IS stored in the cluster on said chip.

The dealership CAN adjust the mileage but only in one direction... UP.

Example: if your car needs a new cluster, they order a new one with 0 miles, install it and then adjust the mileage UP to whatever your car had previously. 

the only exception is cars with less than 25(?) miles, they can be set back to 0 at the dealer.

for Mk3 this can only be done at the dealer because their computers are different than a VAG-COM.


Story: I have heard that once the odometer hits 299k or 399k it resets back to zero or 400k but all you see is 0. if this is true you can theoretically set the mileage to 480,000 miles and only see 80k on the dash... just what I heard, its hard to get the tech with the computer at the dealer to do it and when my brother worked there we had no reason to try it.

and if your mileage difference is only 6k from old cluster to new cluster whats the big deal? I just went from 80k to 172k  sucks but I know what the real mileage is! thats all that matters to me.

Good luck!


----------



## Rob Cote (Dec 6, 2006)

Why not just drive the car until the ACTUAL mileage matches the mileage of the new cluster, then swap? That way you don't have to do anything crazy but keep driving.


----------



## wascallywabbit510 (Aug 2, 2009)

robs92jettv2.0 said:


> Why not just drive the car until the ACTUAL mileage matches the mileage of the new cluster, then swap? That way you don't have to do anything crazy but keep driving.


Honestly, that isn't a bad idea. It is the most legal of the ones I have heard (other than buying a brand new one and programming it to your exact mileage).


----------



## Fyler1 (May 28, 2010)

Because what if the difference between the 2 clusters is a ridiculous number, like say... 100k miles?


----------

