Immobilizer bypass

[Bill Verburg]

Originally Posted by Lorenfb

"yes, the DME can be changed to a '97 or '98 US unit which does have a replaceable chip"

As I said, there's no replaceable chip.
Here's a picture of a '98 993 DME.
This DME is externally reflashable.

"the single chip sets used in the 88 pin US DME's are removable"

Furthermore, as seen in the picture, these DMEs are not "single chip" but have
two key/major 'chips' (two microcontrollers/microprocessors).

"chip sets used in the US 88 pin DME's are not reflashable"

Right, which only applies to the US '96 DME.
As mentioned above, the '97/'98 are reflashable.

"yes, the DME can be changed to a '97 or '98 US unit which does have a replaceable chip, there are also specialty shops that have the skill and equipment to resolder a chip into the '96 unit."

- From an earlier post -

Again, the '97/'98 does not have a replaceable chip. With much effort and Mickey Mouse mods,
the '96 circuit board can be re-worked with added components to allow coding changes. This
is highly unreliable from what I've seen from some of my customers that had it done."

All this has been discussed and clarified many times on Rennlist.

and here is a '96 twin chip set



If the '97/98 DME is externally reflashable, then this is the first I've heard of it. I was taught that there was no way to flash the '97/98 in situ.

Yes, there is a lot of information here and at Rennlist, it's nice of you to actually share some of it for a change, if it's true of course

[Lorenfb]

That last picture is of a '96.
The flashability of the '97 & '98 DME has been discussed before.

[Bill Verburg]

Originally Posted by Lorenfb

That last picture is of a '96.
..

Very good, It was even labled as such in the post. Amazing

[nod okim]

So where and what kind of chips would I get?and it will work on my 1998 ecu would I be able to use a 1995 ecu in my 1998 993?

[Bill Verburg]

Originally Posted by nod okim

So where and what kind of chips would I get?and it will work on my 1998 ecu would I be able to use a 1995 ecu in my 1998 993?

Talk to Steve Weiner at Rennsport Systems about reprogramming you '98 DME, you still need the relay bypass shoen in the first post here.

Using the '95 DME in a US '98 would require a new harness from the engine to the DME as well. I know one fellow that did that, don't know if it's worth it or not as there are some other mods that will be required too.

[nod okim]

sorry i just saw your thread it wasnt on my last page

[vcotta]

Will this 3(30) 5(87) jump wire bypass trick work on a 1999 boxster?

[Bill Verburg]

Originally Posted by vcotta

Will this 3(30) 5(87) jump wire bypass trick work on a 1999 boxster?

You'd have to check the wiring diagrams for the car. Remember that the chip in the DME also needs to have the correct programing

[nod okim]

The specialized ecu doctor in Florida can bypass your immobilizer 600.00 it comes with the relay and no more fob needed . Li just had my 1998 993 done and it worked great put the parts in and the car started right away

[jpachard]

Is this the same procedure for a 964? I have the jumper block but it doesn't want to fit in the bridge relay socket.

THe car is a 1993 with a Steve Wong chip.

Cheers, James

[Bill Verburg]

Originally Posted by jpachard

Is this the same procedure for a 964? I have the jumper block but it doesn't want to fit in the bridge relay socket.

THe car is a 1993 with a Steve Wong chip.

Cheers, James

I don't have the 964 wiring diagrams but Porsche doesn't usually change wiring for these sorts of things.

Are the female plugs in the panel different in some way?

[jpachard]

Bill, the spot in your picture is just blank on my car with no option to install anything. Do you happen to know what relay # it is on your car?

Thanks in advance!

James

[Bill Verburg]

Originally Posted by jpachard

Bill, the spot in your picture is just blank on my car with no option to install anything. Do you happen to know what relay # it is on your car?

Thanks in advance!

James

It's the starter relay, #61, the relay consists of 2 parts, the outer part is controlled by the immobilizer the inner by the key, you want to jump the outer part so that it is always hot when the key is on. on a 993 it is pin 3(30) to pin 5(87).

If you have wiring diagrams it's easy to find as these are on the outer section of the relay circuit

[jpachard]

Bill, Thanks for the information. My starter relay is not in socket 61, even though the documentation inside the relay box cover states that it should be. I'm quickly learning these final 964's from the factory are anything but normal...


Cheers, James

[Noah930]

Bill (or any others):

Why does this immobilizer problem happen in the first place? Bad relay/chip/soldering?

I have a friend with a '97tt. (US model, 27K miles, stock everything AFAIK.) He's been having progressively worsening problems with the car not starting after unlocking the doors with the key fob.

[Nine9six]

Originally Posted by Noah930

Bill (or any others):

Why does this immobilizer problem happen in the first place? Bad relay/chip/soldering?

I have a friend with a '97tt. (US model, 27K miles, stock everything AFAIK.) He's been having progressively worsening problems with the car not starting after unlocking the doors with the key fob.

It could be a dying battery in the immobilizer fob. I carry a spare in my glove box, just in case.
Dead immobilizer battery = no start.

[Noah930]

Originally Posted by Nine9six

It could be a dying battery in the immobilizer fob.

Already changed (as has the car's battery).

[motion]

Bill, thank you for all your info on this subject. I was in Las Vegas a couple days ago fueling, in a bad part of town, and my key fob apparently died. Replaced the battery, but no love. Miraculously, I had another fob with me, which worked. Otherwise, I would have been stranded.

I don't know anything about Steve Wong chips, but going to start doing my research

[nl911]

Just installed chip and relay bypass in my 95 Carrera 4, immobilizer gone! Car starts every time with out playing with key fob. Runs better and idles better also, cant say if there is more power for sure ,but it seems that way. Got the parts from Steve at Rennsport Systems. Thanks Steve!

[autobonrun]

Originally Posted by Nine9six

It could be a dying battery in the immobilizer fob. I carry a spare in my glove box, just in case.
Dead immobilizer battery = no start.

I haven't had any immobilizer issues but this thread reminded me to check my key fob battery.

Primary key still works. Backup nearly dead. I haven't changed the backup FOB battery since I bought the car in 2005. Went directly and bought new batteries. Changed the backup's battery and it works fine as well now.

From now on, my primary key fob battery will be changed annually with the house smoke alarm.

Because of the complexity of the I-delete, I'll just live with it and keep fresh batteries.