Mazda RX7 FD3S 1995

[kitten13]

hello,

I can not correct the mileage on an odometer with a (319502) EPROM.

11791 miles on the odometer and I would like 50000 miles, can someone help me.

Thank you for your help.

[neospeedo]

The algo in these Mazdas are very different than all other Mazdas

Here's a dump for you to try... Has 49350

Try and Repost

319546

[kitten13]

ok thank, you know the meter pinous so I can plug it in and check.

[neospeedo]

That I don't have sorry. You may be able to see some indication of power and ground written on the blue printed circuitry on backside.

[kitten13]

Thank you, does it work.


Here are the pinouts

http://s4.photobucket.com/user/purerx7/media/clustinstal-0212.jpg.html

[Soss]

For these we have not been able to change the mileage, you need to load a data set that has been saved from another vehicle, this limits you to the data sets available.

[neospeedo]

just to note: the dump i posted earlier is from another vehicle

[kitten13]

I did not understand, what should I do?

[neospeedo]

just load up the dump and power up

[Rerouter]

Soss, the milage on these can be set, I've not yet made the process idiot proof, but want to make clear it can be done,

[kitten13]

I find it hard to follow, in french automatic translation distorts your sentences if you not write properly. :burnout:


Sorry for my English

[diagtech]

What he means is you have to put a dump/dataset from another rx7 with a similar value to the one you need then your speedo will show those miles try these the ones in miles will show equivalent in kms

[apexseal]

I have been comparing two dumps with about 9,000 km difference between each other but I can't get it calculated no mater how many swaps, xor's and other calculations I use. I can't even get a CRC (maybe not present).

[Rerouter]

Because you really need a long set of sequential dumps to even begin to see it, these are weird

[Mike1001]

We import these from Japan - I've tried to work these out without success! I have a few dumps - mostly from here. I know Digiprog UK can do these

[apexseal]

In the "rx7.rar" one of the files shows everything in plaintext in the ascii. Has anybody used this file "as is"? 0150-0156 is untouched, maybe a marker?.
347624

[apexseal]

If I remove all FF's and the "1000", I end up with 118 bytes which is the exact size of the "plaintext" block at the end. Now the thing is how to arrange the bytes and what operation needs to be done for it to display the info accurately in plaintext. After that, I assume that it can be changed to whatever mileage is needed. My personal scenario is that my eeprom and the whole cluster is dead due to somebody's wrong doing while doing a welding job on my car but I do know the actual mileage since I barely use the car and I wrote it down on my log on my last trip, I purchased a whole cluster but it has less mileage on it and I don't want any trouble. My car is in "showroom" condition and I want things 100% as original as possible, that is why I embarked on this journey LOL...

If I'm digging in too deep in a forbidden/private subject please let me know or delete my posts I don't want any trouble, I just saw this thread and got involved in the conversation.

[captain crackers]

As the mileage is going up, I think the easy answer would be to run it up up with a function (square wave) generator. All you need is the 12v+, -ve and speed pulse points. Far easier than trying to work out the encryption on this one. Arthur.

[apexseal]

I saw this posted at another site.

Mileage for RX7
FE36-FC68-F8DB-F1BB-7E37-FC6E-FFFF-FFFF-
FFFF-0******00-******2-FFFF

So I guess the string between "FFFF-FFFF-FFFF" and "FFFF" should be the mileage string.

[apexseal]

Will an ST UA741 (I gota few laying around) a couple of resistors, potentiometer and a single cap do the trick for the square wave circuit? I can do that no problem. I'm not going to venture in the decryption... LOL

[captain crackers]

Have a look on ebay. There are function generators for a few (less than 10) dollars or google it for a circuit diagram to make one. Arthur.

[neospeedo]

Here's an idea, take the chip or eeprom (remember to bridge crystal) and copy it right over to your working cluster , and then your back to original :burnout:. Then no "trouble" with your showroom car. I do see a lot of these for repairs and its like anything else thats electronic and aged has leaky caps. Luckily the 93C56 memory isn't ever affected.

[apexseal]

I pulled the chip and tried to read it on my Superpro 3000 programmer and won't read, I noticed a little "explosion" mark right at the vcc leg under the microscope in my shop. That is why I'm doing this, I have "revived" the original cluster I had to replace diodes, all caps and few other components, I installed the chip from the ebay cluster and everything works. All is left is correct the mileage LOL...

[apexseal]

So turns out it is kansey algo.

[jomberykaso]

So turns out it is kansey algo.


thank you friend...lol....you made my day.......lol.......have a good day.

[apexseal]

No problem... Por nada...