MadIrish

Wondering if anyone can help. Have dug through old posts and nothing quite matches up with the issue I am having.

I went to look at a very nice '99 996 C2 with 60k miles today . I like the car quite a bit. Body is in great shape, tan interior is a bit scruffy (that color leather doesn't age too well on the seats), but fine. Engine purrs, drove well. Little greasy in a couple spots, but I couldn't see the source, not too worried about it at this point. Priced where I think a car of this age and shape should be.

Problem is that there are some electrical gremlins and I don't know enough to know if it is an immobilizer issue or something else.

Symptoms:
1) lights do not come on in interior when either door is opened
2) Lock switch on dash does not lock or unlock doors
3) Key fob does not actuate locks, nor does it pop the frunk (it has juice, light blinks when pressing buttons).
4) Key, when turned in drivers' door lock, only locks/unlocks drivers' side
5) Two quick locks of the car wit the key, no beeps
6) holding key in lock or unlock position does not affect the windows or roof (either to raise or lower windows, or to raise the roof)
7) Car starts and runs fine.

I did not check the fuses, but the owner did...I have not seen the '99 manual, but from what I see on other years, the fuses that affect the central locking and alarm would also affect the windows and the dash.

Any ideas or are there simply too many possibilities?

Thank you.

jaetee

I think you're barking up the right tree.

It's easy enough to check. The immobilizer is under the driver's seat, which needs to be removed to get to it... I would take it out and open it up to inspect. I bet you find a partially corroded circuit board or some other sign of moisture in there. But be careful messing with it, you could end up causing your car to no longer start. (I learned that from first hand experience).

You may end up needing to take the car to the dealer, or soliciting the help from a company like ECU Doctors. http://www.ecudoctors.com/

Good luck!

dan_189

Here is a good video on the removal of the unit:

MadIrish

It is a car I'm looking at, so the owner isn't going to let me pull out the seat any time soon, unfortunately. Not even sure the owner truly realized the extent of the issue. He told me "the dome light and door lights don't come on when you open the door", but mentioned nothing else.

Macster

Since you are just able to look feel along the door bottoms for any signs of dampness. Check under the seats for same.

If you find dampness at the door bottom the door membrane (one or both sides) is shot. It happens.

The door membrane can be replaced but if it has leaked long enough to let water into the dry side and affect the window/door electrics chances are you'll have to replace more than the door membrane.

If the cabin floor under the seats is damp there is a new security module in the car's future.

Even if the car feels dry check the body water drains. If these are full of trash or look like they have been full of trash in the past then the chances are water overflowed into the cabin and the security module has suffered even if it is not currently damp.

Unless you can get the car at a price that mitigates what you will have to spend to bring the car up to spec I'd say walk away. This is not the car you are looking for.

jaetee

New Immobilizer requires new keys. You're looking at anywhere between $1000-$1600 if sorted by a Porsche dealer. ECU doctors may be able to repair immobilizer for less than half. But they can't tell you that until you send them your keys/immobilizer/ECU as a group...

I would follow Macster's suggestions and if you don't like what you find from further look, start looking for another car.

Here's a silver '99 C4 that looks promising in my area, for what I think is a hellova price (with full black leather). I've not seen the car in person, but mentioning this just to illustrate some of the deals out there, depending on how opinionated you are regarding mileage. https://tampa.craigslist.org/psc/ctd/6061999635.html

MadIrish

Thanks, guys. Yeah, my understanding was that it'd bee around $1500 if the immobilizer was the issue.

Again, honestly, I think the owner didn't really understand the extent of the issue. I wrote him an email laying out all the symptoms and my suspicion that a new immobilizer was in the offing....explained what that meant in terms of parts, labor, reprogramming...IF that was the real problem and told him this was not a scare tactic to get him to drop his price.

Suggested that he should get it fixed (or at least properly diagnosed) before trying to push the car. He said "thanks for the info, it's nice to meet new Porsche enthusiasts" and that was it. So, he's gonna look for some sucker who doesn't know enough to check this stuff. So, maybe he DID know the extent of the issue. Shame, cuz it was a great car at a good price ($18k for a 66k mile '99 C2 Cab with a very clean exterior and a sweet sounding mill).

I have walked away. I saw a second car that day (a 2000 C2 cab in ocean blue metallic with a dark gray interior with 25k miles and the IMS/RMS done just last November with the LN retrofit), price is higher than where I wanted to be, but not much higher than what I think the current market up here is for a low mile car with IMS work. I put in an offer and its been accepted. Will do PPI on Thursday. Fingers crossed.

jaetee

Wow... 25k miles is like new! And with IMS sorted to boot... Best of luck on that one!

MadIrish

PPI worked out fine. Only thing they really found was old tires (I knew that), some codes in the top, lights and emissions system that are probably related to a dead battery, and the need to replace the AOS soon (little caked up with some old oil) - the last I expected anyway. Alignment and wheel are little off, will fix with the new shoes.

Otherwise, the motor is clean and dry, the body is fine (except for stone chips and some scratches.....and some collateral damage where someone rubbed at the chips thinking they were dirt and did even more scratching) Looks like my bank account is going to get lighter, after all! woo hoo.

MadIrish

woohoo....the 2000 C2 Cab is now in my garage.

piersonm

I know this is a dead thread however, I’m hoping there’s someone on here who has run into the same issue and fixed it… I am having the exact same symptoms that you described earlier and I’m assuming it’s a bad immobilizer, but I’m confused because I don’t see any moisture in the carpets or at the bottom of the doors

I just bought this car five days ago, and it was super clean with a clean exterior and interior and these issues with the immobilizer never came until about 500 miles into the ownership

steam_mill

I'm pretty good with cars. I have a proper scan tool also. I couldn't get my car to start. Changed ignition switch, still would not start. Fearing immobilizer issue, took it to an independent as I did not want to go down a rabbit hole needlessly. Ended up being 2 bad ignition switches.

Not saying thats your problem but sometimes an independent saves you money and time.

piersonm

The only reason why I think it probably is not an ignition is for the fact that my car runs and drives perfectly fine, the only symptoms I am seeing is the fact that the door locks do not work when using the button other than the driver door when manually turning it left or right with the key from the outside, the windows do not roll down, and none of my interior lights will work when the door opens like the dome light and the door, courtesy lights… Do you think you could still potentially be an ignition problem?

steam_mill

Nope. I don't think immobilizer either. My guess is the actual door locking mechanism and one of the many microswitches.

piersonm

oh really? That’s encouraging to hear… I have it scheduled for a local repair shop to take a look at it this Friday for a diagnostic so I can see what they tell me is causing these issues and I’ll update