Lionworks Auto

Hi forum. I'm a new Porsche convert having just purchased an '04 Cayenne Turbo last week as a winter driver when not using a 456M. Sorting thru the usual issues - most are corrected (coolant lines, driveshaft, etc).

But this one has a peculiar issue where the light switch will trigger everything to light on the dash, including the actual red needles on the gauges and the LCD's are on and lit, but the backlight behind the instruments (tach, speedo, boost, temp, gas) remains dark.

I've read a few of the threads here about this and sounds like it's the actual cluster - maybe a component on the mother board. Other threads indicate the actual light switch but I don't think that's the issue here as everything else comes on (I wish it were).

My question is, if I buy a used cluster which I've found eBay, that registers less miles, can it be reprogrammed to my actual mileage? And if not, what does that mean to the car fax, future sale and all that jazz?

Thanks for your support as always. Ed

wrinkledpants

You can't reprogram a used cluster, sadly. Might hurt resale a bit, but if it's documented it might not be so bad. Or, just get a cluster with close to your mileage. It will only show up as a discrepancy if it's a lower mileage that what was last reported. So, just make sure the cluster is at least at the mileage of the last time it was anywhere official (dmv, dealer, any shop). Having 10k more on the cluster than whats on the car is better than less with a discrepancy. Besides, mileage isn't as important with these cars as condition and documentation when it comes to resale.

There are places that might be able to fix it. I'd start by seeing if you can swap in another cluster to see if it works right. if so, then you know it's the cluster. If not, then maybe the harness or connection. No idea if the needles and backlight are on different lines in the harness.

Lionworks Auto

Great advice thanks. I'm going to have my shop trace all the harnesses and see if issue first...will report back

Lionworks Auto

Anyone know if an 06 cluster from a Turbo S fit in my 04 CTT? Seems like physically is identical? I know will need programming but any other hidden issues that will keep it from working?

bigbuzuki

One issue I can recall is that the early Cayennes had a module known as the electrical gateway situated in the cluster.

Later models had the gateway situated external to the cluster.

Lionworks Auto

Assume the gateway is related to the immobilizer? That doesn't sound good...