jay@EZimmoblock.com

Last year, I embarked on a project to design a 993-compatible FOB, driven by curiosity and the possibility of improving performance and reliability.

While the circuitry posed minimal challenges, reverse engineering the Porsche encryption scheme proved difficult. So I got sidetracked on a mini encryption research project. After much trial and error and experimentation, I deciphered the encryption and built a single prototype that I tested on my '97. To my delight, the prototype worked out to 60 ft — 2 to 4 times greater than the 3 other FOBs I tested side-by-side. Actual range is going to vary with each 993, but these results suggest users could reasonably expect to get at least twice the range they are currently getting.

The new design operates on a lithium coin cell, a change that eliminates the often-troublesome OE battery terminals. With a shelf life of 10 years and a demonstrated lifespan of over 20,000 uses, most users may never need to replace the battery. The new design also closes a security loophole in the older OE design.

First-article prototypes are ready for testing. I’m seeking a few owners willing to use one for a while and provide feedback. If the results prove promising and the interest is there, production could commence shortly. Thanks to the simplicity of the design and high level of integration, I anticipate being able to offer these at a significantly lower price than OE. Hopefully, this may encourage owners without a backup FOB to get one.

Currently, I have a limited number of prototypes available and seek beta testers who:

• Have a US/Canadian-market Drive Block-equipped 993 with a functional, unmodified immobilizer.
• Regularly drive, preferably on a daily basis.
• Know their 4-digit immobilizer PIN code.
• Are capable of programming FOBs, preferably with prior successful experience.

Please note that the initial prototypes operate at 315MHz, making them unsuitable for RoW cars (for now). If you're interested in participating, please PM to discuss further.

Thanks

Grapeape

How does one obtain the 4 digit immobilizer pin code?

gavonder

Interested, but not sure about the 4 digit pin.

Balibay

I would be interested. I programmed one on my two FOBs, so I have some experience. Does the increased range in anyway increase the probability of someone “hacking” your FOB?

Jay777

Listening in and recording a FOB transmission is EASY - at any range. Decrypting it, generating the rolling code and encrypting the message the car is expecting next is the hard part, take my word for it. The increased range introduces negligible additional risk.




OOPS, used my old account...

JB 911

Great project Jay. I'.m RoW so can't take part but am looking forward to seeing the results. Nothing worse than walking too far from your car to be able lock it then having to walk back to it. I'm not very cool to start with add in that maneuver and it's totally uncool looking

jay@EZimmoblock.com

The 430Mhz RoW version is just a simple re-tune of the 315MHz design, so no issue there. To get price down, you have to make these in large quantity, so the plan is to focus first on North American 993's and move forward with RoW if the demand is there.

Not sure how close you need to get, but if you're down to a few ft (with a healthy FOB), the problem may be in the immobilizer. This issue is pretty common. The fix is discussed here. With a little skill it can be a DIY. I've done a number of these for my IMMO BLOCK customers with impressive results.

paranoidandroid

I can attest to the immobilizer fix. My range went from 2 ft to about 15ft by replacing the caps.

JB 911

Thx. My range is probably 20-25'. I guess just spoiled with modern remotes..

11Quarts

Interested but would have to find my 4-digit PIN.

~Dave

jay@EZimmoblock.com

Thanks everyone. All the beta test FOBs have been spoken for. Wish I had more to give away! If the testing goes well I should be able to have them available towards end of May. If you’re in the market for a spare, I may kick things off with a group buy.

hoyas490

Just commenting to say this is an exciting potential new part and I'm eagerly awaiting their availability for sale.

Also, thank you for surfacing this fob range repair / mod with the fresh capacitor caps. Just added that to my warm weather to-do list of cheap little projects!

systemsc

An original FOB range repair typically results in an overall range of about 20+ feet, which for most, is more than adequate. It should be noted that the overall range is not only a function the of FOB!
An improved range may also require a capacitor be replaced in the immobilizer.

pp000830

Saw several replies asking how to mate the fobs to the car.
Here is a page that covers this:
https://993servicerepair.blogspot.co...ming-made.html
Andy

systemsc

Here's the procedure I use when helping Porsche independents and 993 owners;

1. Open door, insert key, and turn key to run mode. Immobilizer light should come on.
2. After about 15 seconds, the light should go off. Turn key off then on (cycle key).
3. After about 15 seconds, the light will start to flash on/off. Cycle the key to enter each
of the four digits. Wait about a second between each digit.
4. If the code is correct, the light will again begin to flash on/off. Depress the button on each remote one at a time.
5. Turn the key off, exit the vehicle, close the door, and test each remote.
6. If step #3 doesn't occur, the ignition switch is most likely bad. The immobilizer then needs to be
programmed externally.