Mileage correction on 1995 Audi A4 V6?

[theanalyst]

Hi guys,
Great forum you have here by the way!

I have just bought a 1995 Audi A4 2.5 v6 and the guy 'forgot' to tell me he had the clockset replaced allegedly due to a fault in the PCB.
The new clockset reads 100k miles higher than the car has actually done (backed up by MOTS and service history) so I want to correct it.

I have no experience with A4 odometers though however Ive used tacho pro before on a BMW E36 iirc

Am I correct in thinking I am going to have to remove the clocks and desolder the eprom as this cars PIN is not the same as the one in the ECU?

Please can anyone tell me what procedure and equipment I must use, I would be very grateful :)

I have a Willem eprom reader and laptop etc

many thanks

[z786]

if you have the original dash, you can swap the eeproms

[martin292009]

post dumps.. 93c56...

[theanalyst]

if you have the original dash, you can swap the eeproms


thanks for the replies

I have the original dash, but I have never seen it working and only have his word for its that it is!
If I have to desolder the eprom from this one, it would surely be easier just to reburn the eprom?

Where can I find a dump for my 93c56?

thanks again

[z786]

funnily enuff, its in the 93c56 lol
read yours and post it here

[theanalyst]

funnily enuff, its in the 93c56 lol
read yours and post it here

Ah, but how do I find the mileage in the dump?!!!!
I will indeed read mine and post it here!! Is the eprom easily accessible? thanks

[alimmo]

1.Simply remove and replace 93C56 with the original and see if it works, if not dump is trashed therefor 2. program new 93c56 with new dump. the first option will not require any software but soldering skills. the second you will need to request a dump but see how you get on with replacing the original.
Let us know how you get on.:listen:

[alimmo]

Ofcourse I am just re-affirming what Fez786 is saying.
PS didnt mean to hijack the thread.

[alimmo]

Sorry Meant Z786

[afitijuana]

thanks for the replies

I have the original dash, but I have never seen it working and only have his word for its that it is!
If I have to desolder the eprom from this one, it would surely be easier just to reburn the eprom?

Where can I find a dump for my 93c56?

thanks again

just to reburn the eprom ?:ahhhhh:

givem a try in the used cluster an see what's come up.

[theanalyst]

ok guys
Can anyone tell me which eprom I need to remove!! (or where it is more specificall)
Have taken the old clockset apart and can see several chips!!

on the rear of the pcb theres 1 x 16 pin chip coded no
L4938
W991D9505

this one is almost under the speedo

and then on the other side, near the rev counter there is a same sized 16 pin one coded

2003A
9503



I have only desoldered eproms from ECUs before, and these eproms are smaller....!!

I have this as a 93C56
http://www.google.co.uk/imgres?imgurl=http://www.futurlec.com/Pictures/93C56.jpg&imgrefurl=http://www.futurlec.com/Memory/93C56.shtml&usg=__UVr8WEC914nbUEoB5bzmDoNx6X8=&h=216&w=200&sz=17&hl=en&start=4&itbs=1&tbnid=V5o3HJmO2oMiiM:&tbnh=107&tbnw=99&prev=/images%3Fq%3D93C56%26hl%3Den%26sa%3DG%26gbv%3D2%26 tbs%3Disch:1

but cant see one anywhere?!!!!

[z786]

hi mate, you need 2 be looking for an 8 legged chip
smaller than the size of your little fingers nail lol

like the one circled in red

[theanalyst]

hi mate, you need 2 be looking for an 8 legged chip
smaller than the size of your little fingers nail lol

like the one circled in red

Thanks mate ;)

Anyone know where the little b*ger is though!!!? Im trying to remove the actual speedo off the clockset

update// just had a thought. Could the seller have been lying and these in fact arent the original clocks but a set that are for a new Audi A4 or different one maybe?
There is no 8 pin chip soldered on to this PCB!
I am going to remove my working one to see if they are the same but if they arent then thats my answer!! Ive been had (sort of!)

How else can I find out what this clockset is from?

thanks

[z786]

that cant be possible, have you checked both sides of the pcb?

are there any stickers on the clocks? there should be a date of when they wer made, should giv you an idea if they wer for your car

[martin292009]

Audi All spedometer calibration pics - odometer Audi information (http://tachosoft.com/pics/audiall1992-1994.htm)

programmer 93c56!

[theanalyst]

thanks guys

Well, I have found the 93c56 chips on both clocksets. They were much smaller than I expected!!

ok, here is both dashclocks!! the ones on the left are my fully working A4 ones that are in the car (or were) the ones on the right are allegedly from the same car....... :( (they have same PN on the outercasing but are totally different PCB and layout wise)


http://i103.photobucket.com/albums/m139/and1c2/P6260863.jpg

As a result Im guessing the eprom from the clocks on the right of the pic wont work on the proper A4 clockset on the left?

So if I burn an image of the chip from my proper A4 dashclocks Im hoping someone here can help me please find and adjust the mileage?

thanks

[z786]

they are wrong clocks, completely different
just post a dump from the working clocks on here
then tell us wat current mileage is and wat u want on there

[theanalyst]

they are wrong clocks, completely different
just post a dump from the working clocks on here
then tell us wat current mileage is and wat u want on there

thanks a lot z786 :)
Will dump the chip on monday night and post the file up

Thanks

[theanalyst]

Ok, well what a PITA this is turning out to be :(
I desoldered the chip this morning, forgot what fun surface mount components are to desolder without a hot air station!!

I then dug out my Willem v4.5c eprom burner and associated hardware, but now I find there is no socket small enough for this eprom...!!

There is a socket marked 93Cxx which I thought was the one i needed, its an 8 pin socket, but its about 2x as long and 2x as wide as this teeny weeny chip Ive desoldered...!!!

Can anyone please advise me how I can read this little &*&^%^%^&*&&^ thing

I have only ever burned 27Cxx type eproms so this micro world is new to me!!

ALso, the software wants to know if its an 8 or 16 bit chip???


Im guessing I need to solder wires between the legs and socket connections, but am puzzled why the 93cxx socket ie much bigger than this chip!!!! Also, Im guessing I match the 'chip labelling' orientation with the other chips on the willem and this should be the right way around?
Thanks!!!!

[theanalyst]

can anyone please confirm if I just need to solder wires between the 93c56 and the 93Xxx socket on my eprom burner please? (the sockets bigger but still 8 pin) and Im a newb with these tiny chips!

thanks

[z786]

read post number 3
http://www.digital-kaos.co.uk/forums/f133/eeprom-reader-tacho-universal-138855/#post654151

you will need that, its the best n safest way

[theanalyst]

read post number 3
http://www.digital-kaos.co.uk/forums/f133/eeprom-reader-tacho-universal-138855/#post654151

you will need that, its the best n safest way

Thanks mate ;)

will order one now and post back

[theanalyst]

Hmm, just a quick question. Have seen they are based in hong kong and I need this thing asafp..!

but I just found this adapter in my willem burner box

http://i103.photobucket.com/albums/m139/and1c2/P7020899.jpg

http://i103.photobucket.com/albums/m139/and1c2/P7020900.jpg

Now it says its SMD 93cXX and 24cXX adaptor
Now what its adapting to I dont know... but Im guessing I have to solder the eprom on the underside of this and then plug it in to the burner, then desolder etc

What are your thoughts on me using this??

Otherwise I will order the one you kindly linked but I just badly want to get the dump of this chip asap!!and the adapter above will definately be quicker, if a bit more hassle!

[z786]

that adapter u posted is perfect
jus make sure u get pin 1 to pin 1 (jus make sure its the right way round)

[theanalyst]

Well Im slightly stuck at the minute guys :(
Ive got my Willem all fired up and working ok, soldered the chip to the adapter in what Im 99% sure is the correct orientation
http://i103.photobucket.com/albums/m139/and1c2/P7050905.jpg
http://i103.photobucket.com/albums/m139/and1c2/P7050904.jpg
http://i103.photobucket.com/albums/m139/and1c2/P7050906.jpg

and although the eprom burner says it 'chip read ok' it is only giving me lots of FF FF FF s in the buffer (eg a blank chip!)Now at first I thought I may have accidentally erased the chip by an anomaly with the eprom burner, but I have also tried it with the chip not in and read an imaginary 93c256 and it is still saying chip read ok!!!

Has anyone got any ideas on what may be wrong>?

The eprom burner hardware tests fine and all the right lights come on when I read the chip, even the one next to the 93c adapter... its just not taking data off it?

Could the chip be the wrong way round?

[theanalyst]

oh, and although it says '8' on the eprom I have tried reading it as a 16 bit as well with no difference :(

[theanalyst]

ok, sorted it and at least got the dump! It was a bloody setting I had missed in the willem software with a tickbox saying 'program SMD chip using ICSP connector'
The first time I saw it and selected it it read no problem..!

Well, thats if the dump is ok. its 256 bytes and i would be ultra grateful if someone who knows what they are doing could help.

Current mileage on this chip is 223,266

and it should actually be 131,300


:rock:

heres to hoping ....

.

[z786]

could you tell me what is says on the back of the speedo ie. VDO or UK NSI??

see if you can find any stickers or print on the PCB

are the above in miles or km?

EDIt: its ok mate, yours is a UK NSI, jus tryin 2 calculate for you, still need 2 knw miles or KM

[theanalyst]

could you tell me what is says on the back of the speedo ie. VDO or UK NSI??

see if you can find any stickers or print on the PCB

are the above in miles or km?

EDIt: its ok mate, yours is a UK NSI, jus tryin 2 calculate for you, still need 2 knw miles or KM
many thanks mate

It is in MILES and not KM :rock:

[z786]

ok mate here goes..........
im half asleep, one of the 3 dumps should work, not 100%
jus work with me on this one, try them and see which one works for you

report results plz

[theanalyst]

ok mate here goes..........
im half asleep, one of the 3 dumps should work, not 100%
jus work with me on this one, try them and see which one works for you

report results plz

You are officially a star mate :rock:
Have you got any hunch on which one to try first?!!!
and what would be the effect of a non working one? zero mileage or incorrect mileage?!

THANKS AGAIN!!!!!!

edit// will defo report results..!

[z786]

try them in order, worst case senario is incorrect mileage

[theanalyst]

try them in order, worst case senario is incorrect mileage
will do
thanks mate

[theanalyst]

balls!
Im getting a write error when I burn the chips.
I am using the Willem 'erase' function and it verifies it is empty.
But when I write Im getting an error

error at 0x000001
chip = 0x1B
Buffer=0x12

The voltage on the adapter is at 12v

Has anyone got any ideas what the problem may be?
Could the chip not be fully erased? thanks

[z786]

havnt got one of them programmers mate
hav u got a user manual? or even spare eeproms same type?

[theanalyst]

havnt got one of them programmers mate
hav u got a user manual? or even spare eeproms same type?
Ive grilled the user manual mate.Cant find anything useful or that could be wrong, same with the internet, Ive searched high and low and not found a fix yet.

If it comes to it I will get a couple of blank eproms and try it with them as soon as soon as they come! thanks

[z786]

check if all pins are making contact

[theanalyst]

It is writing 256k to the chip
It just doesnt seem to be correct though...!!
CHeck this compared to the original bin file I burned back on it

edit// I will check all the pins now!

[z786]

corrupt dump mate, the file name is written in2 the dump lol

[theanalyst]

corrupt dump mate, the file name is written in2 the dump lol
lollol
well Ive checked all the pin legs and no difference.
am thinking of buying a new chip to try it on, as Ive read every thread on the web and found one where someone had had the same issue

but before that,

I may desolder the chip and try it the other way around? do you think this is worth it?

If the white bar on the end of it is the same as the indent marker on the adapter then its already the right way...????!

aaaggghhh

[z786]

if you can read the writing on the eeprom, pin 1 is bottom left side

the circled bit is wer pin1 shud sit

[theanalyst]

thanks mate
it is on the right way round then as I thought :/

I will remove it and resolder it on again tonight and if that doesnt work I will get a new chip and try burning that.

Then if that doesnt work Im going postal :banghead:

[theanalyst]

Update/

I have managed to burn a chip successfully at last after much messing with the Willem.
Will post back the results when back in the car :)

[theanalyst]

Well, the bin file I read before burning the chip is slightly different now.
i wonder if the first one was corrupt?

Does anyone have a known good bin file for this chip please?

[theanalyst]

This is what tachosoft says


Car type: Audi A4 UK NSI new - 93c56
The mileage is stored in the next lines:
0000: 12 00 12 00 12 00 12 00 12 00 12 00 12 00 12 00
0010: 12 00 12 00 12 00 12 00 12 00 12 00 12 00 12 00
0020: 12 00 12 00 12 00 12 00 12 00 12 00 12 00 12 00
0030: 12 00 12 00 12 00 12 00 12 00 12 00 12 00 12 00
0040: 12 00 12 00 12 00 12 00 12 00 12 00 12 00 12 00
0050: 12 00 12 00 12 00 12 00 12 00 12 00 12 00 12 00
0060: 12 00 12 00
where the next bytes:
12 00 - is a mileage

Im guessing it means the bytes after the 12's are the mileage? my hex is poor!

[theanalyst]

can no one help ?????????????????????????????????????????????

[z786]

12 00 is the mileage mate, the number of times you have 2 repeat it is mentioned in same post

first calculate what your mileage was, then re insert the new mileage the same way ie.

12 00 is the mileage but you might see it like this
00 12 in that case you need to put it the same way

its called byte swapping

[theanalyst]

12 00 is the mileage mate, the number of times you have 2 repeat it is mentioned in same post

first calculate what your mileage was, then re insert the new mileage the same way ie.

12 00 is the mileage but you might see it like this
00 12 in that case you need to put it the same way

its called byte swapping

thanks for the info mate.what I cant work out, and would be grateful if someone could explain, is how the mileage that my bin file should show

223,266

Is displayed in the hex??
Because I cant figure out how to find it?!!! if its in the first section, is each number displayed as a different byte? or what!!
The addresses are different to the quote I posted earlier and it just repeats 31 12 31 12 seemingly all the way through the mileage bit. If someone can give me a pointer or three once I understand it I will work on it till I can sort it!!!

http://i103.photobucket.com/albums/m139/and1c2/pic_3-1.jpg