p38 1996 Gems mileage

[mikkre]

Hello everyone on the forum.
I have also made the same mistake by changing the speedometer (due to several faults) from another car to my own car, this increased the mileage by over a hundred thousand.
Now that winter is starting to recede, I thought I would investigate the matter and possibly correct the readings. I have read related articles on various forums. Now I ask: If I reset the BeCM as described on the forum and then set the eeprom from the original meter, will the original mileage be displayed? B. R. erkki

 

[Datatek]

Hello everyone on the forum.
I have also made the same mistake by changing the speedometer (due to several faults) from another car to my own car, this increased the mileage by over a hundred thousand.
Now that winter is starting to recede, I thought I would investigate the matter and possibly correct the readings. I have read related articles on various forums. Now I ask: If I reset the BeCM as described on the forum and then set the eeprom from the original meter, will the original mileage be displayed? B. R. erkki

If you can remove the good EPROM without damaging it, then after first resetting the BECM mileage count to zero, yes the correct mileage will display when you put your EPROM back in and the BECM will update to the correct mileage.

 

[mikkre]

Ok, I'll try. It'll take a while, but I'll get back to you and let you know. Many thanks!!!

 

[mikkre]

One more question: Can I check the mileage from a separate instrument cluster by connecting it to a 12V power source? I have several instrument clusters and I don't know the mileage of all of them.

 

[Datatek]

One more question: Can I check the mileage from a separate instrument cluster by connecting it to a 12V power source? I have several instrument clusters and I don't know the mileage of all of them.

Never tried it, let us know how it goes.

 

[mikkre]

Now I have connected the disconnected cluster to the power supply. +30 connector C242 pin 4 and 14 pink. Ground connector C242 pins 7 and 17 black. +15 C402 pin 1 green. When I connect +30 to the power supply, the indicator lights come on for about a second, after which they go out. The power supply's A-meter does not show a reading when the indicator lights are off. The information display does not open. This happens repeatedly when I turn the power supply back on.
In addition, connecting +15 from connector C402, pin 1 green, does not affect anything.
I do not have any more specific information about the condition of this instrument cluster, judging by the markings it is from a scrap car.

 

[Datatek]

Now I have connected the disconnected cluster to the power supply. +30 connector C242 pin 4 and 14 pink. Ground connector C242 pins 7 and 17 black. +15 C402 pin 1 green. When I connect +30 to the power supply, the indicator lights come on for about a second, after which they go out. The power supply's A-meter does not show a reading when the indicator lights are off. The information display does not open. This happens repeatedly when I turn the power supply back on.
In addition, connecting +15 from connector C402, pin 1 green, does not affect anything.
I do not have any more specific information about the condition of this instrument cluster, judging by the markings it is from a scrap car.

I'm pretty sure all the display info comes from the BECM. The EEPROM in the instrument cluster only has a life of 100,000 read /write cycles so can only be back up storage with no connection to the display.