My speedo works intermittently. When it works it sometimes sticks, and it moves with a ratcheting motion. Also my fuel gauge is not accurate.
I have two mechanics tell me I need a new instrument cluster, but I forgot to ask about the ODOMETER. I want to keep the accurate mileage on the car.

I contacted a instrument repair shop but they only fix the fuel gauge.

Does anyone know of a repair place that can fix the speedo (or verify it is broken) and fix the fuel gauge also ?

 

Use an OBD2 Bluetooth adapter to verify proper signal.

 

I haven't worked on the G35 cluster yet. I'll check at work and find out what chip needs to be swapped or copied.

 

I would buy a used working set. Test it in your car to make sure it works correctly. Then swap the EEprom or have a shop swap it if you aren't comfortable soldering SMT parts. The EEprom is a S93C66 on the back side of the PCB (Side with main connectors)

 

That's a good idea. I know how to solder. So I take it, the eprom, holds the mileage ?

 

Yep, I have done it on quite a few G20's before. The G20 uses a older style EEprom but functions the same. I opened up a 06' FX35 cluster at work today to verify everything. Another cool thing is that you don't have to remove the gauge needles and face since it's on the backside.

 

I wish I knew how that stuff worked better...

So if you replace the eeprom what happens to your existing odometer miles? Is there any programming involved with replacing that component or is it just the "memory" for another component that's doing the programming?

 

The EEprom is just a 4k storage chip for the odometer, and trip computer when power is removed. As long as you have your original EEprom chip from your cluster you can put it in a working replacement and retain your mileage. Without the chip there would be nowhere to save the mileage data. If you can decode the data on the chip you can just erase a chip and enter in the mileage but that is way more complex and requires equipment most people don't have.