fbfisher

Thought I would post this in case others would find it useful. I got locked out of my car with the alarm blasting away, here's the story:

I could tell that the remote was sending a signal to the door locks because the red lights on the doors would flash as if receiving a signal, only the locks would not function. I locked the doors with the key which set the alarm (red lights flashing). The remote would not unlock the doors. The key would not unlock the doors or deactivate the alarm. I was able to turn the key and open the door simultaneously, which set off the alarm. The remote would not turn off the alarm. The alarm shut off by itself after a few minutes. By some miracle the remote started working again so that I could cycle the alarm and door locks normally and deactivate the drive block. I drove straight to the dealer and then the next miracle happened, it malfunctioned again there at the dealer (I was worried that this would become an intermittent problem that would only happen at the most inconvienient times - but not in front of a repair tech). Imobilizer works great, car completely imobilized until new part arrives.

Diagnosis: Malfunctioning Imobilizer Control Unit.
Location: Under the passenger seat.
Cost: ~$800
Warranty: Covered under extended warranty
Availability: Part not in dealer stock. due in next week

max911

shortly after buying my car, I had a problem similar to yours. i could not set the alarm or lock the doors with the remote.
a Porsche dealer did the diagnosis and said it was a control unit under the seat. I think it was about $400.
i remember that it did have a 928 part number. i will try to find the number.
later i looked at the LA porsche dismantler website and saw that they sell them for $75.

max

max911

Fred, looking at the PET some more.....I see two control units under the seat

928 618 260 03 control unit/anti-theftdevice/central locking system. (about $300) ...this is the one that failed for me

993 618 159 02 immobilizer control unit (about $400) it looks like it may have been superceded with another part number when i looked at the price list. 993 618 059 02

do you know which one it is that you need??

EDIT: judging by the $800 price, I would guess that it is the immobilizer control unit with a new remote too??

fbfisher

I just called to check. They have ordered the Immobilizer Control Unit, I did not ask to confirm the part #.

max911

i would lend you mine for the weekend Fred, but it would probably involve the dealer having to reprogram it , then me reprogramming it when i got it back..... $$$$

can't you keep the Boxster??

fbfisher

No, they needed the Boxster back for a better customer (higher cost repair). I don't fit all that well in a Boxster anyway. It was fun having a 5 speed manual for a while but I have no idea how you guys steer, shift, talk on the phone and drink coffee all at the same time without the handy buttons on the wheel.

Lorenfb

Because of the location of the immobilizer, the units are easily water damaged,
especially in cab top cars. Water damaged units will manifest problems
intermittently, besides a total failure.

The second unit found under the passenger side is the actual door lock, lights,
and horn controller. This unit and the immobilizer work together as a pair. Either
can be the source of a failure with the remote system. Without proper diagnosis,
the repair can be costly in the end.

Have to love them Cabs, kinda like sponges!

Good Luck
Loren
'88 3.2

Terry Adams

When I owned the '87 Cab, I came out from a hotel after a rainstorm to find about 1" of water on the driver's side floor. The ECU under the seat miraculously lasted another week, then was toast.

24FPS

damn! fred... ever since you mentioned it, i've been very leary.
& friggin' b i n g o !!! today the car locked itself three times!!!! right when i pull the key out of the ignition. & mine's a '97 too.

could i be subconsciously doing this because.... i'm feeling left out??? i hope that's all it is. i think i'll change the battery in the key, yeah...

time will tell... i'll leave the top down as to avoid any lockouts though

fbfisher

One other data point on this, the first indication that a problem was developing was that the door chime was ringing when I would open the door - strange thing was that key was out of the ignition, lights and turn signals were off, no apparent reason for the chiming.

Thanks for the data Max and Loren, I have called the dealer and asked them to be sure that it is the imobilizer and not the lock controller, and that for safe measure and that it is covered under the warrenty, they may want to consider replacing both.

fbfisher

Still waiting for parts. Confirmed part #'s:

993 618 159 02 = imobilizer $422.11
993 618 259 02 = remote $109.26

I don't know why the remote is necessary. I had bought one several months ago to replace the switchblade version. maybe it means I will have an extra.

Lorenfb

You don't need a new remote. The old remote should be "accepted" by the
immobilizer if it's O.K.

Good Luck
Loren
'88 3.2

fbfisher

Interesting development related to this. I went to pick up my car and found the interior in pieces. Both seats removed as the imobilizer is under the driver seat and the alarm control is under the passenger seat.

Two techs were scratching their heads - they could not get the system to function. I described to them the symptoms and they focused in on the issue related to when I would remove the key, the door chime would still ring.

They determined that with the key removed, the imobilizer still "thought" that the key was in the ignition due to a faulty switch in the ignition key switch. The latest threory is that the door chime circuit needs to "see" a ground, which is triggered when the key is removed from the ignition. It the ignition switch is faulty then the imobilizer "thinks" the key is still in the ignition and therefore will not work. The reason the red LED on the door flash is because the imobilizer is "seeing" the remote. The lack of a ground from the key switch prevents the imobilizer from arming.

I don't claim to understand electronics and such, this is what I gleened from listening to them. They were also pouring over the schematic of the electrical.

This points to the importance of talking to the tech. I had described the issue and symptoms to the service writter but this had not been communicated to the tech.

So far I have a new imobilizer, new alarm control, new remote, and I anticipate a new key switch.

Shant Ohannessian

And i was just about to buy an imbolizer for mine. So do you think its from the ignition? I have the exact same symptoms as you described. Thanks for keeping us updated.

24FPS

sorry to hear this fred. man... good idea to see if one can get a tech to listen as you describe it to the service writer.... esp. when it's electrical!

good point about the ignition/key switch... bet that's been the prob all along.

please keep us posted. & bol