Rhetro

Hello folks,
it's been a bit -can't believe i've owned her for 9 years now -where does time go...i digress

Ok, got a very strong battery. when i engage the starter, i just get a clicking/vibration sound. I've heard of the following possibilities:
1) the battery in / or the key fob itself needs to be replaced. I replaced the battery (even though the voltage read ok) i get solid lights on the key, but
it won't talk to the car. Called Porsche and they told me that those fobs (even with new batteries) need to be updated ? reconditioned ? something along those lines. So i just did everything manually -delaying as long as possible the payment of $200-300 or something like that for a new key).
2) Now, nothing happens. I'm told that this has to do with the key
OR
3) a 7.5 amp fuse that needs to be reset/ replaced ?
I was going to take it in to Porsche for its annual service, but now it won't even start. I'd hate to have to have it towed.

what do y'all think?

Thanks !

ZuffenZeus

Normally, the clicking sound is usually from a bad battery (not keyfob battery) or grounding issue on the car.

Re: the keyfob. Do you have a backup key that works? We need to confirm the RFID is still functional. There are three parts to these keys: 1. key blade 2. Electronic board (control access to the car) 3. RFID "Pill" that works with the ECU and Immobilizer to provide a security check when attempting to start the car.

The keyfobs DON'T need battery power (i.e. CR2032) to start the car! The RFID is a passive device.

DBJoe996

The 7.5 amp fuse is in the immobilizer. ^^What he said. But, when you go to engage the starter and it doesn't turn the engine over, all conditions (hand shaking with DME and immobilizer) have been met. So you have to start with diagnosing the 12V circuit from the battery to the starter. Make sure the ground from the engine to the body is clean and good. Check the jump point in the engine bay to see if you have "strong" 12V there.

HoustonCgrBkr

When mine did what you described, a new battery solved it.

allcool

Well, lets start with your first stated problem(seems to be a few things going on here)...

If you get the clicking/vibrating sound and the starter doesn't turn over the engine, its got nothing to do with the key fobs or rfid system.
Its one of a few things.
1) How was your battery tested,? just because it has 12v at the terminals doesn't mean it has the amperage needed to turn over the engine. A bad/partially shorted or weak cell can do this. You need to load test the battery.
2) Could also be a bad battery cable not letting enough juice thru to the starter. A bad y cable is a common 996 problem. Many different good ways to test this cable, do a search.
3) Could be as simple as a bad starter.

"Now, nothing happens. I'm told that this has to do with the key"
When you say "nothing happens" do the dash lights come on when the key is turned on..? Assume you mean the 'clicking vibration sound' is gone now..? If so, all the above could do that

If your key fobs don't unlock/lock the doors and they have good batteries in them, its more than likely the fobs are bad and you need new ones programed to your car. Another common 996 problem area. It is a 20+ year old car.... Most times, ECU Doctor in Florida is the most economical way to go here.

jmo

Rhetro

Ok. got it. that all makes sense.
so if it were "bad handshake" i wouldn't even hear the clicking (bad batt or short to the starter) sound?

is it even true that these fobs go bad ? it is 19 years old (original)

Porsche just quoted me 564 for everything...
It is the service center after all -i knew this going in...so i get it; not happy, but i get it -it's not a Hyundai

thanks

Rhetro

addendum:

The dash lights DO come on when I turn the key. Removing the FOB from the equation, past experience would tell me it's a bad battery.
OK:
Bad Y cable

Yes: the FOB stopped locking / unlocking the doors a fews weeks back. Been doing it the old fashioned way; which has worked -until now.

DBJoe996

The circuit board in the key fob goes bad over time. Mine did and I have used the good old fashioned way key in the door to lock/unlock. If you don't have the original key tags with the coded numbers for programming then you have to go the route of buying new keys from Porsche and have them programmed into the DME/immobilizer. There is no other way. But your problem is in the 12V circuit from the battery to the starter.

allcool

The key won't lock/unlock the doors when manually turning the key in the door key slot...?

Rhetro

i'm sorry, that was vague.

The key has worked manually for the doors and the ignition.
it will NO longer work with ignition

AZPete

Last week I had the same issue - rapid clicking and no start. The battery was 4 years old (3-year warranty of course), so I replaced it and problem solved for $195. If your battery is more than 3 years old (no matter the warranty), I'll bet it's your problem. Not difficult to replace it yourself and avoid paying for on-site service or towing.

Rhetro

Yeah, if i need to swap out the battery, i'm only too happy to do that so I don't have to have it towed.
I kept it on a trickle charger and it was showing 95%. But come to think of it, i do believe that it's about 3 years old now.
I'm going to start with a new battery. Hopefully that's it. it's time for a new one anyway -even if it's something else. May as well remove a bad batt from the equation.
I'd much rather drive it over to get serviced than to have it towed there.

thanks again!

996-CAB

Your symptoms are consistent with a bad Y cable. A three year old battery on a tender should not die. If the Y cable is corroded, it will prevent the battery from fully charging. When you replace the battery, keep your eye on the voltmeter in the dash. If it drops to 12V or lower when the engine is warm and the radiator fans are on, you have a Y corroded cable. I replaced the Y cable, battery and alternator and the voltage barely drops below 14v when fully loaded.

Rhetro

ok. I suppose that makes sense with the rest of the input here, thanks. Everything has been working great since i've owned it (9 years now). this is the first time i've had this issue with it NOT starting. The trickle charger tells me there should be enough voltage to at least start it; so i'm guessing the batt can still be bad. But what you guys have pointed out is something that i'm guessing is MORE than possible on a car that's 20 years old. I've babied her, but that doesn't mean that things don't age and break/go bad. so a bad
cell
or Y cable

At least you guys have ruled out the fob / immobilizer theory which is where i was going..

AZPete

Rhetro, whatever you do, you'll disconnect the battery so it needs to be "reset". Once the battery is re-connected, turn the ignition on but do not start the engine, then keep it on for 60 seconds, then turn the ignition off. Lower each window, then close it, then press the up button again. Questions? See Owner's manual.