Can't I just replace the Immobiliser? Why do I have to go to the dealership?

[99 Boxcutter]

My 2001 Boxster S got caught in a New Orleans flash flood and corroded my immobilizer and now the car won't start and does a faint ticking.

Because it was under the drivers seat and super easy to remove, I took it out and put it in a Crest Ultrasonic cleaner. Alas, it didn't save it.

So I went on eBay and found this complete with keys: But someone told me that "only the dealership can replace ECU/immobilizer"

[JFP in PA]

Originally Posted by 99 Boxcutter

My 2001 Boxster S got caught in a New Orleans flash flood and corroded my immobilizer and now the car won't start and does a faint ticking.

Because it was under the drivers seat and super easy to remove, I took it out and put it in a Crest Ultrasonic cleaner. Alas, it didn't save it.

So I went on eBay and found this complete with keys: But someone told me that "only the dealership can replace ECU/immobilizer"

It has to be coded to the car, requires a PIWIS system to code it.................

[piper6909]

The immobilizer is programmed to the car. You can change the Immo with a couple other parts (can't remember their names) along with the keys to make it all work, but doing that would basically change the identity of the car. It will take on the VIN of the donor car.

There are places where you can get it fixed besides the dealer. ECU Doctors is one, but their prices are close to those of the dealer. There's also a member on here who could fix it for a lot less.

[Qckslvr]

Qmulus is the forum member you want to talk to. Great guy and a lot cheaper than the dealer.

[78F350]

Originally Posted by 99 Boxcutter

... So I went on eBay and found this complete with keys: But someone told me that "only the dealership can replace ECU/immobilizer"

JFP is (of course) correct, but there is a difference between having a car that is correct and a car that you can enjoy without having to spend lots of money at a dealership. Two of my current (5) 986s have had the "immobilizer box" swapped and not been reprogrammed. Both cars are highly depreciated in value with a rebuilt title due to flood damage. It will present a problem if I need to have them serviced at a dealership, but there really isn't anything on these cars that I won't do myself if time is available. I don't expect to sell either car in the foreseeable future, but I would fully inform a buyer. My '04 Flood car: The Houston 04 SE

* Check to see if your insurance policy will cover the correct repair. Many full coverage policies will, but it may actually 'total' your car.

* The set that you linked is NOT what you need. it does not include the box under the seat and will be a waste of your money.

*To make the car function you will need a matching set compatible with your car's model and year consisting of: key fob with transponder "pill", Engine computer (called DME or ECU and mounted in the trunk on the firewall), and immobilizer box (called central locking unit) under the driver seat). The ignition switch, key blade, and signal transducer module on the ignition stalk are irrelevant, but are often included.

*Try to find a set for sale with multiple keys. I got one with 3 keys for $500.


*Forum member Qmulus has made affordable repairs for many forum members, swapping the correct coding to a good immobilizer box. ECU Doctors can repair and recode these for less than the dealership cost as well and makes a good waterproof box.

*You may find the best deal here in the forum classified section if you ask someone who is parting out a similar car.

[99 Boxcutter]

Originally Posted by 78F350

JFP is (of course) correct, but there is a difference between having a car that is correct and a car that you can enjoy without having to spend lots of money at a dealership. Two of my current (5) 986s have had the "immobilizer box" swapped and not been reprogrammed. Both cars are highly depreciated in value with a rebuilt title due to flood damage. It will present a problem if I need to have them serviced at a dealership, but there really isn't anything on these cars that I won't do myself if time is available. I don't expect to sell either car in the foreseeable future, but I would fully inform a buyer. My '04 Flood car: The Houston 04 SE

* Check to see if your insurance policy will cover the correct repair. Many full coverage policies will, but it may actually 'total' your car.

* The set that you linked is NOT what you need. it does not include the box under the seat and will be a waste of your money.

*To make the car function you will need a matching set compatible with your car's model and year consisting of: key fob with transponder "pill", Engine computer (called DME or ECU and mounted in the trunk on the firewall), and immobilizer box (called central locking unit) under the driver seat). The ignition switch, key blade, and signal transducer module on the ignition stalk are irrelevant, but are often included.

*Try to find a set for sale with multiple keys. I got one with 3 keys for $500.


*Forum member Qmulus has made affordable repairs for many forum members, swapping the correct coding to a good immobilizer box. ECU Doctors can repair and recode these for less than the dealership cost as well and makes a good waterproof box.

*You may find the best deal here in the forum classified section if you ask someone who is parting out a similar car.

Nice, that will work on a 2001?

[99 Boxcutter]

Originally Posted by 78F350

The ignition switch, key blade, and signal transducer module on the ignition stalk are irrelevant, but are often included.

So if I replace the computer system, I can simply swap the key circuit boards?

But first, I should try to be my immobilizer repaired first, right?

[Starter986]

1. Why from the factory wasn't the immobilizer installed in the trunk/firewall?

2. Could a DIYer install the immobilizer in the trunk?firewall?

Thank you.

[78F350]

Nice, that will work on a 2001?

No, the one I pictured is the one I bought for my '04. You can find deals like that though for the '01 if you keep looking.

So if I replace the computer system, I can simply swap the key circuit boards?

Yes, you can just swap the electronic guts of one key to another - circuit board AND transponder.



Here's the minimum set of what you need to swap. A couple years ago I watched for them and picked up several sets for about $300 each. Forum classified and eBay, but prices have been going up on parts.



Having Qmulus or ECU Doctors repair or replace your current box is probably the best course of action to keep the car correctly configured.

[78F350]

Originally Posted by Starter986

1. Why from the factory wasn't the immobilizer installed in the trunk/firewall?

2. Could a DIYer install the immobilizer in the trunk?firewall?

Thank you.

I have no idea why they chose to put it there. I think the best place to move it would be up under the dash. You'd have to pull out the interior on the left side, unwrap and split out the harness, then probably splice/extend some of the wires.

I have not tried it, but here's a pic I took of a harness I removed. you may not even have to extend any of the wiring after it's separated out:
main-mid by Jon Russell, on Flickr

[Qmulus]

There are lots of threads on this, but I will summarize.

If you get water under your driver side seat, don't wait until the alarm/immo module starts malfunctioning, but rather disconnect the battery ASAP (MOST IMPORTANT to stop corrosion) and remove and open the alarm/immo module and dry it out, preferably with compressed air to get the water out from under the relays. That is where the worst damage is done. The longer it is wet with power applied, the worse the corrosion. If things are not working, just drying it out will not save it. The corrosion damage must be repaired and damaged components replaced.

Replacing the DME, Immo and key transponder "pill" with the parts from another car will get it working, but is a BAD idea in my opinion, as your car will now have the electronic ID of the car those parts came from. Therefore, you will not be able to program new keys or replace any of those components as the programming codes Porsche has for your car will no longer work. So, basically you just changed your car's electronic VIN to that of the car those replacement parts came from.

What is the "correct" way to fix this? Well, you can get a new immo/alarm from your local dealer for $500-$900 depending upon the part number, and have the dealer program for $150 or so, or you can get it repaired, or get a replacement used alarm/immo module and get it "cloned" to match your original. Note that you really must have the exact same part number and sometimes also software revision for this to work.

[JFP in PA]

Originally Posted by Starter986

1. Why from the factory wasn't the immobilizer installed in the trunk/firewall?

2. Could a DIYer install the immobilizer in the trunk?firewall?

Thank you.

Lack of room.