Speedometer cluster

[jwgn777]

Is there any way to match a speedometer cluster to a particular vehicle (911) via the serial number on the cluster? Let me add that a friend of mine wants to purchase a vehicle and ask me to check the miles against the the working hours on the DME. with my tester. I found that the working hours were a little high but not completely out of an acceptable range. I could be wrong however i use this method 20 K miles usually turns up around 550 hours on the DME. Does this calculation sound close?

[white99c2]

Why do you ask that question?

[jwgn777]

[COLOR="Purple"][B][B]You are now asking me a question?

[Aerkuld]

You're calculation doesn't sound too far off. Your numbers would work out with an average speed of around 36 mph, but you probably know that. It doesn't take much to lower the average speed and it just depends what conditions the owner(s) drove it under. Regular commuting in stop and go traffic would make a big difference for example. I could see that being the case on a lower mileage car.

What sort of mileage are you talking about and how big is the discrepancy?

With all of that said does anyone know where the odometer reads it's mileage? I suspect the instrument cluster is dumb and the mileage is stored somewhere in the DME. In other words, plug in any instrument cluster and it will read the same mileage, but that's just my guess . . .

Anyone?

[KevinH1990]

Originally Posted by jwgn777

[COLOR="Purple"][B] Is there any way to match a speedometer cluster to a particular vehicle (911) via the serial number on the cluster?

I don't know of any formula for matching a serial number on a cluster to the vehicle VIN in which it was installed. If you have a Durametric, you can read the VIN from a cluster.

The mileage and VIN are stored on an EPROM (Erasable Programmable Memory) chip in the cluster. The VIN is also stored in the DME, but I don't believe the mileage is stored in the DME.

I have a Boxster and installed a 996 cluster in it. If you would like to have instructions for programming a 996/986 cluster send me a PM with your e-mail address and I send them to you. There is some general information about the process in this thread: http://986forum.com/forums/general-discussions/43017-carrera-gauge-swap.html

[jwgn777]

I have a Bosch KTS Porsche tester and i did not see the vin # read out one my tester under instrument cluster. Did I miss something? I did see it under DME vehicle info. I will try it again.

[Aerkuld]

Originally Posted by KevinH1990

. . . The mileage and VIN are stored on an EPROM (Erasable Programmable Memory) chip in the cluster. The VIN is also stored in the DME, but I don't believe the mileage is stored in the DME . . .

Thank you for the clarification. Having never swapped an instrument cluster I really didn't know, so it was a guess - wrong! Appreciate the voice of experience