New to me 2005 Cayenne
 

Lucky you to have the V6. No cylinder scoring worries for you.

I can't help, other than to say to forget about everything other than getting past the immobilizer system. I don't have direct experience with that on these cars, but they are usually designed to foil people who steal cars for a living. Professionals who would steal a car like this when it was worth 40x what it is worth now - and the immobilizer security has not lessened with the deflating market value.

Don't underestimate the work required to bypass or fix that. And if you never solve that problem, everything else will have been a waste of time. So move that up to #1 on your list, and put the rest of the list on standby.

Welcome and Good luck.

That seat is really bad. I have heated seats and they're nothing like that. Luckily, Cayenne seats are cheap on eBay.

As far as the immobilizer: Boxsters commonly have immobilizer issues due to water damage. Look on the 986 Boxster forum here or on 986forum.com and you might find some hints. The immobilizer is keyed to the specific car, so I don't think you'll be able to bypass it. I expect your two options are to have it rebuilt or to get one from a wreck.

does it lock / unlock ?
what dash message if any are you getting
does the key work the locks in the front doors ?
what happens when you turn the key

Reply
 

Sound like the key is the right one, but it may need to be re "paired" with the ignition. A dealer visit or some shop with a PIWIS may be needed, def not something you can check any other way that I know of

Mike reply
 

Run in the car with the doors closed for 2 hours four or five times over a week or so and the smoke smell should clear up. Don't breathe what it puts out. The Ozone clears up on its own within an hour or so after it automatically shuts off.

Use epoxy for the seats backs and while it sets/cures.

As has been said these security systems are designed for cars that cost about $120K 2005 $ top end, they are all tied into the computers, I don't know how you could hot wire a bypass, maybe someone else does but starting without the key is out of the question in my experience , sorry

Immobilizer active
 

Lots of the modules/units in even the earliest Cayenne are programmed to the VIN# of the vehicle. That was Porsche's way of making the modules worthless on the used-parts marketplace - lessening the temptation for thieves to steal and part out the Cayenne. Most of them have to be programmed by a dealer with a PIWIS to tell them what VIN# they are going to accept and work. And to add to the worthlessness of the modules used - most of them can only be programmed once. That makes old Cayennes with these sort of problems really questionable to buy, and probably why this one was sitting all that time before you bought it.

I think at the least - you'll have to visit a dealer and talk with someone knowledgeable in the service department. That probably isn't the Service Adviser - it's probably someone like the actual Service Manager. He should have an idea if new keys can be mated to your existing immobilizer. And as I noted earlier - a lot of the "new" keys found on eBay do NOT come with the immobilizer chip in them. That's something that is proprietary to Porsche - and while I suspect Russian hackers have probably figured out how to clone them - it wouldn't surprise me if the new keys you get are chipless - sold with the expectation that the chips out of the old keys would be used to make them useable.

And lets hope that someone who owned it before you didn't do something like swap in a used ECU or something in the hopes it would work magic and unlock the ignition and let the car start.

I've often said "A cheap used German luxury car can be the most expensive car you've ever owned.." and it's things like this that validate that statement.

I'd suggest starting to read: https://rennlist.com/forums/cayenne-diy-224/ - and it's possible the immobilizer problem might be caused by some corroded wiring under the carpeting. If it filled up with water this time, you can be assured that it has in the past and the wiring harness splices are almost certainly toasted by now. Having $200 into the vehicle is a good thing - means you'll make a profit if you decide to part it out ($200 = battery and keys?)

As far as solutions and opinions - you'll get what you get. The opinions are usually based on experience - which can be translated into paths to follow or not follow to achieve your goal.

This issue has come up before. I can even duplicate it with my own car.

There is a transponder in the key fob. It's coded to the car. Without the correct code, the car will not start. At all.

There's not a separate "Immobilizer" module. This isn't a 928, where you can wire a jumper across a couple of pins on a plug and bypass it. It's part of one (or more?) of the computer modules. In theory, it should be possible to hack into the computer and defeat it, but in reality, if this had been done, we'd likely know about it. It's a bit more complicated than 'jailbreaking' an I-Phone.

What happens is that the circuit board fails and the transponder stops working. So there's no code being given to the car. A couple people claimed success by opening the key fob, finding and repairing a bad solder joint or broken board trace. But only a couple. Most have had to get a new key from Porsche and have the dealer recode the key (the new one and all the old ones) to the car. It takes the dealer to do it. Again, a couple people have claimed that they know someone who had it done by an outside source, but I tend to be skeptical of it. There are some indy shops that have gotten the factory computer system, but I have a strong feeling that even those systems have had the 'code the key to the car' part removed before being sold. The ability to basically steal any Porsche by recoding keys is something I don't think either Porsche or the insurance companies want in the hands of anyone except the dealer.

In my case, the previous owner had a key fob fail (he had a couple). He bought a new one from the dealer and took the car, the old working keys and the new one to have everything coded together. I have the old, broken fob (he gave me everything, it's pretty cool) and I can get the 'immobilizer' message if I try to use it.
I've been through the 'water under the carpets corroding the stupid crimped and taped wire connection' issue. Lots of fault codes came up on the dash. Immobilizer was not one of them.

You mentioned you had new keys on the way. From where? Actual Porsche?

The problem is that only a dealer can code the keys to the car. Many of them will only code keys if you buy from them. They may give some excuse about 'ensuring the authenticity', but most of it is profit.

You might try taking the key fob to a dealer and see if they can tell if the transponder is working. If, as I suspect, it isn't, then they can sell you a new one and code it to the car. You will have to flatbed or trailer the car in. They need it to code everything together. Plan on spending several hundred dollars. For one key (yes, seriously).

Sorry, but that's part of the reality of owning one of these.