'96 993 Remote Locking System Fail
 

I'm the original owner of a beautiful black/tan 993 C2 with 33K miles. It's been a fantastic car since I drove it off the lot and until recently (Pirelli tire eater aside) it's been remarkably maintenance free. I don't drive it much (1K/yr) and last year, typical battery fail from lack of use followed by a more serious problem involving the remote entry, drive block system sidelined the car for 6 months or more - turned into your basic Porsche owners nightmare.

Found a non-dealer mechanic in Atlanta who (after going through and replacing the usual suspects of keys, batteries, remote box (??) under seat finally decided that it must be the ECU so off it goes for a Drive-block killing flash. So yeah, I'm that guy who hung with the local expert...

So, I've now got a few bucks in my 993 (thousands), no drive block, a couple extra HP (which I like) but the remote entry system remains a no-show. The locking system works fine from inside the car and now at least the drive block system is disabled so I can enjoy the car - just can't lock it. Oddly, if I try to manually lock/unlock the alarm sounds and people look at me with a mixture of disgust and pity ;-)

At this point, my preference is to just install a new entry system. I like Bergville's T-lock system but not sure this is going to work for my '96 in its current state. I think it might given my drive block "block" but can't tell for sure and haven't heard back from Tor as yet. Hoping to be able to set the alarm, lock/unlock the doors and move on with my life. Any insights from fellow travelers would be appreciated. Matt

I installed the Advanced​​​ Key system, it works great. The car locks and unlocks automatically based on a proximity sensor. I went all in and also installed the keyless go system. The 993 now works like my wife's BMW. Get in, push the button, and go. No keys or fob buttons to fuss with.

This system integrates well with the factory alarm module, which remains in control of the door locks. It essentially replaces the immobilizer, which is what actually receives the signal from the fob and commands the alarm module to arm/disarm, lock/unlock

Wow - that's a new thought. I was just trying to get this sucker to operate - hadn't given much thought to going for something that was truly more advanced. Do you still have the drive block system in your 993 or did you reflash?

I have a Wong chip in the ECU which disables the immobilizer, along with the starter bypass relay.

The keyless go option provides the same functionality as the immobilizer. If the fob is not sensed, the ignition is disabled. You need to buy both modules to have full functionality. Otherwise, the keyless entry module will just provide the auto lock unlock function and alarm system, but you won't have the protection of the immobilizer.

Some time back I installed an aftermarket electronic key fob entry on my 86' Carrera. All one does is run a wire to body ground, a hot wire to the battery and a wire or two the central lock toggle switch on the central console.

If you want further functionality, say such as an alarm siren or an ignition kill I am sure more wires are involved but it sounds like your OE alarm is still operational.

If you can lock and unlock your car from the central toggle without setting the alarm off such a minimally invasive system should work.

Any aftermarket alarm has this most basic level of functionality so this is not an expensive or complex fix. I have seen these kits for less than $20 on Amazon, a controller box and two fobs.

Matt,

The advanced system idea sounds really cool.

Be aware that for your 993 it will be different than in an early Carrera because there are more modules involved. I would definitely ensure that you follow Ivan's installation protocol to ensure reliability and no headaches.

If you want to remain OEM the issue will likely be somewhere between the Immobilizer Control Unit under the driver's seat, or the Alarm Control Unit under the passenger's seat.

That should be easy to diagnose and fix on a bench.

Hi Matt,

From your description the issue is with the Immobilizer itself. This is the device that 'listens' to the remote control. Even when you have the ECU flashed you still need a fully functioning Immobilizer module for the remote control to work.

If the ECU is flashed you can indeed install Tore's remote control. It will take over the role of the Immobilizer.

I had a similar setup a few years ago.

Carcentric - this was the insight I was looking for and I had a feeling that there was a "missing module" that had eluded us in my mechanic's zeal to reflash the ECU. I think I'll go with Tore's set-up - sounds like a quality piece of kit and say goodbye to the immobilizer equipment. It might impact resale but that's not important to me - I've owned it since new (same month/year as the birth of my daughter) so I'm guessing she'll get dad's 993. Many thanks.