Programming an Instrument Cluster

Thread Starter

bwilliams60

Joined Nov 18, 2012
1,199
Good evening. On a new adventure. I would like to learn how to remove the information from an instrument cluster, decipher it and the transfer it onto another instrument cluster. So miles, tire size etc should be stored on an EEPROM I am assuming. How do I get this information and what tools do I use? Not offshore junk either unless it is reliable. Thank you.
 
it's not in the cluster. Miles is a tough one because of the reglatory issues. When an ECM is changed, then and only then can the odometer be changed, because those ECM's are "virgin". They have to learn the VIN from the other components or the new ECM be told the VIN and the system verifies that the other components have the same VIN.

I have a tire size issue, but have never asked it to be changed.

That info may also only be allowed with a manufacturer specific tool.

GM, for instance is making the EEROM flashing available by subscription or for say a 3 day period. The VIN sets up just about everything.

Security enhancements like transponder keys may require that your bonded or essentially Locksmith Credentials.

So, the SAE standard will help, but not for proprietary information which can be vehicle specific.
 

Thread Starter

bwilliams60

Joined Nov 18, 2012
1,199
KISS, sorry I have to disagree with you on this. A lot of modern IC's have their own EEPROM chip on board and do store mileage and other pertinent data and can be programmed using an IC programmer. I am wanting to undersrand how to tell what information is on there and what needs to be transferred to make it correct.
RM, no particular model in mind. Will cross that bridge when I come to it.
Reason for question is that I repair clusters and want to know more about them.
 

Thread Starter

bwilliams60

Joined Nov 18, 2012
1,199
Thanks for your help. Problem solved. Light bulb moment.
The EEPROM chip on these clusters is read/write and I have found programmers to connect to them right on the cluster. The info can be downloaded from the old EEPROM and transferred to the new EEPROM in minutes.
There is nothing criminal about this, I simply want to make sure that any cluster I sell has the proper mileage on it. All good, thanks for the help.
 

bmiller2

Joined Oct 11, 2017
12
hello bwilliams... i too am trying to transfer the info from one cluster to another for legitimate purposes ...I am able to transfer the code but i have not figured out the coding needed to correct the mileage...everyone is skeptical because of the obvious legalities involved but we are a legit business importing cars from Canada to USA and we must convert the clusters to American.. We do send them out for this service but i am trying to learn to do it myself...I have not been able to read the chips without de-soldering them first and also if there is a way to bench test the cluster so i can read the mileage at the bench...so any insight on those subjects is greatly appreciated...that being said do you have any recommended software that will help me decode the hex so that i can identify the mileage code and make the corrections ... Also is there a way to convert the cluster from kilometers to miles without messing with the mileage code but maybe the VIN or some other piece of code in the cluster?
 

picoamp

Joined Sep 13, 2018
22
There is nothing illegal in changing the mileage in an IPC, even selling this. It's only illegal to use a wrong mileage in car which has more ;-)
On main process in replacing an IPC, because of an broken one, is to set the mileage to the correct value after the new device is fitted.

Also it is much easier to clone an EEPROM from an IPC whith less miles than to change the value in an existing one. I do not believe that VIN is taking place in coding the mileage, because this would prevent so use the device in any other car.

Modern cars do store the cars mileage in multiple modules, not only into the IPC. But this is only detecable by an OBD reader.

Decoding (aka hacking) the mileage bytes inside the EEPROM could be very difficult. I would start to look for the change. Read the memory, drive for a mile and read again. The differences should show you where it is stored. Next, try to reprogramm the old value and look if it shows the old mileage. Then drive again one mile and read again. If the result in EEPROM is still the same like the last read, there is a good chance of a static algo without any seed (like time or random) and you can start reverse engineering the data.

Most often it is stored multiple times in different "codings". Some are very simple like bitshifting (ROT13 or such) or inversing. You can post data here.
 

Jtford79

Joined Oct 9, 2018
1
Thanks for your help. Problem solved. Light bulb moment.
The EEPROM chip on these clusters is read/write and I have found programmers to connect to them right on the cluster. The info can be downloaded from the old EEPROM and transferred to the new EEPROM in minutes.
There is nothing criminal about this, I simply want to make sure that any cluster I sell has the proper mileage on it. All good, thanks for the help.
Would love to know what programmers you're using for the eeprom?
 

Lumm1413

Joined Feb 26, 2018
13
hello bwilliams... i too am trying to transfer the info from one cluster to another for legitimate purposes ...I am able to transfer the code but i have not figured out the coding needed to correct the mileage...everyone is skeptical because of the obvious legalities involved but we are a legit business importing cars from Canada to USA and we must convert the clusters to American.. We do send them out for this service but i am trying to learn to do it myself...I have not been able to read the chips without de-soldering them first and also if there is a way to bench test the cluster so i can read the mileage at the bench...so any insight on those subjects is greatly appreciated...that being said do you have any recommended software that will help me decode the hex so that i can identify the mileage code and make the corrections ... Also is there a way to convert the cluster from kilometers to miles without messing with the mileage code but maybe the VIN or some other piece of code in the cluster?
I actually know how to do all this if you have not yet figured t out please get back to me with any questions.
 

narkeleptk

Joined Mar 11, 2019
375
it's not in the cluster. Miles is a tough one because of the reglatory issues. When an ECM is changed, then and only then can the odometer be changed, because those ECM's are "virgin". They have to learn the VIN from the other components or the new ECM be told the VIN and the system verifies that the other components have the same VIN.

I have a tire size issue, but have never asked it to be changed.

That info may also only be allowed with a manufacturer specific tool.

GM, for instance is making the EEROM flashing available by subscription or for say a 3 day period. The VIN sets up just about everything.

Security enhancements like transponder keys may require that your bonded or essentially Locksmith Credentials.

So, the SAE standard will help, but not for proprietary information which can be vehicle specific.
I know this post is very old and I am sure TS has found his answers but reading it after it popped up under another thread I felt the need to chime in here for any future readers about the post above as not much in it is accurate.
  • "it's not in the cluster."
    The majority of cars the mileage is indeed stored inside a eeprom in the Instrument cluster. Some cars also store secondary mileage in other places like the the ecm, bcm and bmw's even the keys... but these will only be visible by scan tool. Ones that do not store in cluster are usually controlled in the bcm.

  • "When an ECM is changed, then and only then can the odometer be changed, because those ECM's are "virgin"
    You do not change the mileage when changing ecm's. There are some cars that store mileage just as a reference in ecm's that you can change if you want but it has no effect on visible actual miles of the car. Also just changing your ECM does not make it ok to lower the mileage of the car. The chassis is probably the more important unit to consider when thinking of the wear and tear put on by high mileage.

  • That info may also only be allowed with a manufacturer specific tool. GM, for instance is making the EEROM flashing available by subscription or for say a 3 day period. The VIN sets up just about everything.
    GM does not store any information about your VIN other then what options it had during manufacturing. SPS access is for updating the flash programming of modules and generally does not effect any eeprom memory area's like where mileage is stored. In some of the newer models like chevy cruze where the main mileage is stored in the BCM it may update the mileage for you by taking it from elsewhere in the car when doing replace & program" but its rare that ANY factory tool will set or change mileage shown even when replacing components. "Mileage correction" Its not something manufactures/official dealers support. This is a aftermarket solution.

In my state at least, the only regulatory issues that I know of is if the seller of the car purposely reports the mileage incorrectly on the title with dmv.

Mileage corrections is a common practice in the aftermarket auto world and I can't speak for others but for moral reasons I only change mileage when installing a donor cluster or my client has proof they have previously installed a donor cluster already. I hope most others with the capabilities feel the same.
 

narkeleptk

Joined Mar 11, 2019
375
Programming a cluster is more often going to be the act of flashing the the operating software or firmware if you want to call it that. The eeprom memory containing the mileage, dtc's, trip counter, maintenance reminder and in some cases immobilizer data is generally not affected. Its more of temporary data that is vehicle specific.

When you are cloning a cluster generally you manually read the eeprom data and transfer that.Firmware can be copied as well if needed but generally you are replacing using a donor part with the same part number and firmware already so you really only need to clone the vehicle specific eeprom data.


Cloning the mileage is just that, you copy the exact data for mileage in eeprom from original to the new/donor parts eeprom.

Programming new mileage means you are calculating the algorithm used and then rewriting it to change the mileage.
 
Last edited:

narkeleptk

Joined Mar 11, 2019
375
For some clusters yes there are tools to do it via obdII port. None made by Snap on that Im aware of however if thats what your asking.
 

narkeleptk

Joined Mar 11, 2019
375
I don't believe AAC is the right forum for this type of thing or if they even allow it. You should seek out the more specific forums for car repair. I will say however. The most dependable device runs about $12,000 start up. Then there are some cheaper units that work on some things around $3000 but not all that reliable via obd . Anything cheaper then this is a clone device and 50% of it wont work, 30% will destroy the data in the cluster and 20% may work somewhat.
 
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