car3guy

My 993 came with only one key and FOB, can you program a key FOB from another used 993 key FOB?

JDB1

No you cannot. You must go through a precise and lengthly procedure with a step by step relationship between the old and new FOB and the immobilizer. It took me several frustrating attempts before I accomplished the feat. I had a shop manual and thought I was precisely following the instructions and that is how I learned that the Germans are very precise in their instruction sets, there are no short cuts and no deviations no matter how minor. It takes 43.5 minutes.

nine9six

Not exactly...It does not take 43.5 minutes using this procedure, but you must follow the procedure verbatim.
See attached!
HTH

pp000830

Here is the latest form update

ilko

I bought a second remote for my 993 and have tried unsuccessfully several times to program it. The Alarm icon will just not blink in Step 2 using the above method. My car's an 11/95 build MY96. I've followed the write up to the T but the warning light will just not flash. Any ideas as to what I may be doing wrong or tips or suggestions would be greatly appreciated.

MielsOnWheels

ilko ive got the exact same problem with a fob i just picked up...cannot get the immobilizer light in the clock to illuminate so i cant move forward with programming.

Hopefully someone will chime in.

ReinerFink

Had a friend in the same boat as ilko - right before we dropped the engine out of my car I moved his immobilizer module to my car (seat was already out) and we programmed both keys there. Then moved the immobilizer module back to his car and wa-la.

nine9six

Sounds like you have a ground short in either glovebox light, frunk light, engine bay light, or inside cabin lights.

I had the same condition on my immobilizer light, and it turned out to be a ground short in the cabin lights and engine bay light.

Thanks Andy!

ilko

Interesting! I didn't reinstall the harness for the engine bay light after putting the RS wing on. I'll try to put it in and see if it makes a difference, although my understanding of electrical current is that it shouldn't matter...

pp000830

Make sure you are using the correct imobalizer code. Some confuse the radio or other code with the correct one. A dealer should be able to give you the code. You may have to provide title & registration to get it.

nine9six

Ilko,
I am SURE your electrical knowledge far surpasses mine (seriously)!

However, when researching the problem of trying to program another fob, I discovered that my immobilizer light in my clock was not functioning at all.

Come to find out, it seems to share the same circuit as those lights mentioned earlier, along with the micro switches in the doors and trunk.

After establishing that the micro switches were all working, I pulled all the bulbs from the various locations and reinstalled them one at a time, (while checking for an immobilizer light) in a backyard mechanic methodology of trying to establish where the short existed. Sure enough, it worked and I resolved my immobilizer light functionality and the ready state feedback it provides when programming a remote.

I hope this helps you find and fix your issue...

hoggel

There are two systems that interact to allow key fob programming, the alarm system and the immobilizer system. The alarm system must pass its self check before you can program the key fob into the immobilizer system.

If you lock the car with your working fob the alarm system will initiate a self test. If at the end of the test something has failed the LED lights in the door will double flash. If the test passed the LEDs will single flash. If your car is doing the double flash you will not be able to program the immobilizer. All of the faults that will cause the alarm test to fail, and some troubleshooting tips, have been detailed in pervious threads.

My car had problems in the alarm system when I bought it and I had to work through those before I could program another fob. I eventually got it completely functioning and the fob programmed.

I am now having no luck programming another fob (to replace the one I laundered) for my car and it is not the alarm system causing the problem. I have not taken the time to work through it yet but I suspect it is an intermittent switch in the ignition key mechanism. There is a switch in the locking mechanism that senses the key is inserted, turns on the bong when you open the door and have the key in the ignition. The output of that switch goes to the immobilizer control unit also. If it is not working or is intermittent it will not allow the immobilizer to be programmed.

CarcentricB

There are two different procedures to program a FOB. For a '94 car it takes indeed 43.5 minutes, but later 993's use the process described in the pdf, which takes a lot less time.

So to the OP: please be careful which procedure you apply. If you use the wrong one it won't work.

Regarding the warning light: I'd like to know which ECU controls this warning light. Is it the Immobilizer or the DME? I'm asking because I'd like to understand what happens when the Immobilizer is removed with a tuning chip in the DME. Does this light always stay on, or is it always off? If always off doesn't it even go on briefly when starting the engine (when all lights go on) or is this controlled by a different circuit?

pp000830

If you replaced the bulbs used in the alarm circuits such as the dome frunk or engine bay light with LED lights this may be part of your problem as they technically are not the same sort of resistive loads as a filament bulb. - Just a guess. Andy

nine9six

hoggle's previous posts helped me work through my issues ...I had forgotton about the role the key switch plays in the whole fiasco.

Thanks again, hoggle!

Andy, I had heard/read that before. Was it your post? I was unable to verify if the difference in resistence between the LED and filiment bulbs was valid. Have you confirmed this to be true?

Thanks loads,
Paul