993 alarm / immobilizer issue

[neewum]

I have a 1997 993, and my only working key fob stopped working; I've tried to program a new keyfob using the manual method, but the immobilizer light on the clock doesn't light up to indicate it's in readiness mode to allow for the ignition key flipping to begin.

Now the key won't even let me open the driver's door manually - when I turn the key it beeps once (I hear the clunk from the solenoid indicating the mechanism is working) and a few seconds later the alarm goes off. I'm at a loss as to why this is happening. The car was running up to the point the keyfob died.

The battery is charged, and the usual instrument lights show up correctly (barring the immobilizer fob light)... currently checking all of the grounds I can find to see if something's disconnected/corroded.

I guess on a basic level, can someone explain how the alarm/locking mechanism interacts with the immobilizer? I know the immobilizer needs to send a signal to allow the engine to run, but the problem occurs before it gets to that point.

[yel911]

Just a stupid question, but I have to ask, did you change the battery in your FOB? I only have 1 key/FOB also!!(Someone must have a ___load of 993 FOBS!!!)

[TMc993]

Are you sure your old fob is bad? Sometimes, the small spring that holds the battery in place gets warped, battery contact is lost and the fob behaves as if it is dead. Carefully bending the spring out so the battery fits tight and putting a new battery in the fob may cure the problem.

Also, check all of your door, frunk and engine cover switches. Those switches must be activated and functioning properly for the system to be able to function.

Hope this helps...

[Jcy]

I have a 1997 993 tip and experiencing the same problems with the lock not opening manually. I hear the clunk from the solenoid. The car battery is charged and the fob battery is new. I am trying to program a new fob but can't proceed. Any insight regarding how your issue was corrected. Thanks
JC

[knorrena]

Yeah i think its permanently broken. You should sell cheap just to save yourself the hardship. Call me and i can coach you through the process.

[Nine9six]

A

Originally Posted by TMc993

Are you sure your old fob is bad? Sometimes, the small spring that holds the battery in place gets warped, battery contact is lost and the fob behaves as if it is dead. Carefully bending the spring out so the battery fits tight and putting a new battery in the fob may cure the problem.

Also, check all of your door, frunk and engine cover switches. Those switches must be activated and functioning properly for the system to be able to function.

Hope this helps...

If you are not getting a ready state light on your clock, this is indicative of a couple of possible issues...

As stated above, micro-switches in the trunk, engine bay, glove box, doors, clutch pedal, and ignition switch, are all wired on the same circuit.

Generally, one or several switches are out of adjustment, which results in no ready state light. It could also be a ground short to any one or combination of these circuits.

Had the same issue on my car, and it wound up being chaffed wires to the frunk and engine bay lights. Isolated and addressed the chaffed wires causing the ground fault in the circuit, and got my ready state light, and programmed new remotes.

Without addressing whatever is creating your fault, you will be unable to use your fob. This issue should not prevent you from manually unlocking your car.

P.S. A bad remote battery, spring , or contact in the fob has no bearing on the ready state handshake between the ECU and immobilizer!

[Konsto]

I have a 97 993 Targa (98 build) and not realising I had used the fob with a dead battery, when I couldn't disable the alarm, I opened the door manually , thus setting off the alarm. I did manage after a few minutes to get the alarm to stop. Now when I alarm the car with the fob, I get double blinking lights on the door for about 10 seconds and then the slower blinks. I believe this is the normal state the alarm should be in.

When I disarm the alarm with the fob and put the key in the ignition to the on position, the immoboliser light is solid for about 5 seconds and then goes to a blinking light on the clock dial. Pressing the button on the fob does nothing except the lights on the door blink. The immoboliser light still flashes.

I have read in other posts that I might need to rest the immoboliser/fobs using the immoboliser 4 digit pin code, however I don't have this.

I called my porsche service centre who last serviced the car however they would not provide the code. They suggest i flat bed the car to them, which is a last resort for me as they are 150 k's away.
I have replaced the car battery which needed it anyway, and the battery in the fob.
Does the blinking immoboliser light on the clock dial mean I need to go through and reset the fobs using the reset procedure,or can it mean something else?
Is it true that the last 4 digits of the serial number of the immoboliser control unit is the pin, As I don't want the grind off the plugs to get to the controller if this is not the case.

Any assistance would be greatly appreciated.

Regards, Konsto


POST SCRIPT : What a fool I am, I realised after many hours of frustration that some weeks earlier I had removed the DME relay and forgot to put it back.Once it was put back, amazingly the flicking immoboliser light disappeared.