After sitting unused for about 2 to 3 months my car's factory keyless entry won't work. Since my car has the dreaded drive block I'm unable to start the car.

Tried disconnecting car battery for about 10 mins to reset the car's electronics but it did not help.

Car battery is fully charged since the car has a battery tender. Replaced the battery in the fob but still no response, tried my spare fob and it's the same.

Manually locking the door with the key activates the red indicator light on the door so I guess the alarm is working but strangely no sound from the alarm when I unlock the door. Maybe the horn has been previously disconnected?

Went thru the sequence to bypass drive block and was able to start my car twice but when I tried to reprogram my two fobs the red indicator light on the door does not light up even after pressing the fobs' buttons for almost 30 seconds.

I guess my remote sensor isn't picking up a signal? Which unit should I be checking? Under the driver's or passenger's seat?

Maybe both my fobs are defective?Seems unlikely but I think that's what happened to one guy here on Reenlist. One fob was definitely working a few months ago, the spare was in the drawer for years and I don't remember if it works or not.

 

The alarm module control is under the passenger seat of my 96.
It failed due to the spring wearing out in steering lock mechanism where the key is inserted. Part # 96434791700
Basically the spring in the mechanism wears out and in the process of intermittent contact, fries the alarm module. That was the case in my situation. Porsche offers a replacement steering lock assembly using your VIN # that is keyed to your car. So you can use your existing keys. Takes about 3 weeks to get it from Germany. I ordered thru Pelican. The alarm module needed to be re flashed by the dealer as that was beyond my abilities. Just a thought on a possibility. I know it's frustrating to diagnose.

 

I forgot to mention that the spring mechanism closes the circuit for the alarm to work and allow the key locks to function. When the spring fails, the circuit is open and that is why the locks won't activate with the key fob. Your ecu still thinks your key is in the ignition.

 

Interesting post...subscribed.

tracke3-m3, would you please post the failure mode and fix when you have things sorted out?

Best of luck to you!

 

Yup, same thing happened to my '95 about 4 years ago.
Dealer ordered and installed new ignition and steering wheel lock.
New alarm module too.
Gordo

 

Before going deep and expensive I would clean the battery contacts in your fobs and put new Batteries in them.
If you have a concern about a switch in the steering lock, which I do not fully understand why, I would hose out the lock while it is in the dash with CRC electric motor cleaner as sitting grease may be the issue. One never needs to replace the lock mechanism as it is readily repaired by a lock smith that works on automotive locks.
Andy :-)

 

If you ever get a chance to look at the ignition lock assembly when removed, you will find that the spring mechanism is sealed and no amount of CRC or wd40 fluid can reach it when sprayed into the key hole. Save the fluid. I tried that too. The spring is simply wearing out.

 

I have similar issue before. Ended up removing the alarm module (by pulling the built-in fuse on the connector) and getting a chip to bypass the driveblock.
Probably cheaper than replacing the key cylinder and alarm module.

My question is why the built-in fuse would not prevent the alarm module from frying? when i pull the fuse it is still intact.

 

try disconnecting the battery for 24 hours. Work for me. No idea why!

 

Thanks Spokes, will try to do that.

Thanks Rush, how hard was it to replace the ignition lock? I take the ignition and steering wheel lock is one part? 96434791700?

Would you happen to have part number for alarm module too? Any way to check if it's indeed what's wrong with my car? I'd hate to spend $900 for a part and wait for 3 weeks only to find out it's not the problem.

Could it still be a worn out spring if my car has less than 30,000 miles on it.

hchc, you may be right, might be cheaper (and better) to just get a chip to bypass drive block.

 

The alarm control unit is part # 928-618-260-03. It is under the passenger seat.
It may not be bad yet. It takes time for it to fry. You are looking for the open part of the circuit which prevents your remotes from activating. It can be several things. Check all your fuses first.

I put up with this situation of the car not locking for over a year until I could get to it. It started at about 45k miles and was an intermittent problem at first. You might be able to simply determine if the steering lock spring is the issue by starting your car, turning it off, and then engaging the steering lock mechanism. Try to lock the car. If it doesn't work, try again. It might take 5-6 times and you might get the fob to work on occasion. If it does work once in a while when doing this, then you know it is the spring in the steering lock ignition switch. (pictures attached). When the key is inserted and turned to start the car, the button on the end of the steering lock pushes in. Turn the car off and remove the key and the button pops back out. There is a spring within this arm that pushes the button back out and it locks your steering wheel and completes the electrical circuit that is required to activate the door locking mechanism and the alarm. This spring simply gets tired and wears out over time. I was not able to source just the spring.

I also started to get some faint sound bleed thru from the door alarm buzzer when the key was removed. So the system thought the key was still in the ignition when it wasn't. This occurred about a year after the locking issue started, so it took some time for the extra sound to occur. When that happened it finally dawned on me that it was the steering lock which includes the door buzzer. The alarm had fried out in the middle of that year and I had the Porsche dealer replace and reprogram it. The dealer did not diagnose the ignition lock issue and the fobs did work for about two weeks after returning from dealer service which occurred at the hottest temps of Summer (so the spring was most elastic at that point).

The steering lock part # is 96434791700 and is keyed to your car based on your VIN #. I ordered thru Pelican. The buzzer switch is included, so you don't need that part. However you will need 2 shear bolts # 999-219-017-02-M100 and screw # 99921902402. Look at the schematic. I removed the lower part of the dash first to access everything. The top shear bolt is the only hard to reach part of the process. The alarm settings are unaffected by this lock swap out.

It can be several other things that prevent the circuit from closing and the fob's from activating the locking mechanism, so read thru all the previous posts that are listed here. It can be one of the more frustrating problems to diagnose on your own....... Please post your solution when solved.
Best of luck!

 

Thanks for your help NoRush.

So far I've tried disconnecting the car battery and left it disconnected for 3 days but that didn't help.

Also checked the remote module under the passenger's seat and the fuse isn't blown. Noticed a very faint click when I plug the harness into the remote module, like when a relay is activated. So I guess the remote module is not completely dead.

I'll follow your suggestions when I get time to work on the car. Thanks again.

 

Any update on this? thanks

 

Start at the beginning and test the output of the battery with a multimeter. A battery tender does not revive an old battery.

Pls post the results of the battery test.

 

I don't really use my car so I haven't really bothered fixing this issue but I think it's about time I finally do.

NoRush, it may not be my steering wheel lock mechanism because my steering wheel does lock when the key is out. Am i correct to assume that if my mechanism is defective then the wheel won't lock even if I have my key out?

Does anyone know if replacing the alarm module (928-618-260-03) is a plug and play affair? If not, what's involved? Do I have to take it to the Porsche dealership for programming?

One option I'm considering is just living without a keyless entry and to disable drive block. What would be the easiest way to disable drive block?
I think it involves a custom ECU chip plus replacing a relay, anyone have more info on that?

Thanks.