Key and locks not communicating

[bmsamson]

So I'm having an issue, wonder if anyone out here has had and solved it and can point me in the right direction. 1/my car is an 03 base manual, around 140k miles. 2/the key is less than 2 years old, real P part not ebay special. worked fine since delivered. 3/Recently, the key wasn't working, no red light, so i replaced the battery 4/now I have a light, but it doesn't seem to 'talk' to the car's locking/alarm system. nothing works when i hit any of the buttons (but the light does go on). 5/yes, the car still starts and runs fine 6/when i use the key in the door it locks and the alarm light on the dash does start flashing, and unlocks/deactivates the alarm from the door as well.

It's a real pain to have to open the trunk/frunk from inside, use the key to lock unlock, etc. I'd really like to get this sorted out. Any suggestions greatly appreciated.

[ike84]

Ive had the same problem after disconnecting my battery a bunch of times in a row while working on things. The keys and the clu get out of sync. There's a reset procedure which involves turning the key in the door tumbler a bunch of times but it didn't work for me. I got a Porsche dealer to send me the transponder codes on my keys and will try to reprogram the clu using my piwis at some point. Not sure if it will work or not.

FWIW, it's a quick and painless process to install a $15 aftermarket remote lock controller. You'll have another fob on your keychain but will regain your functionality without too much fuss.

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[bmsamson]

Originally Posted by ike84

FWIW, it's a quick and painless process to install a $15 aftermarket remote lock controller. You'll have another fob on your keychain but will regain your functionality without too much fuss.

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I saw some thing about a sync procedure, but I’m starting to think it only works on 987 and later Boxster’s. I couldn’t get it to work. Tell me more about this remote lock controller option, if you have a moment. Sounds like that might be easier than finding free time when my Indie is open to take it to them to fix the programming.

[ike84]

There have been some writeups about it. Here's the basics...

The immobilizer control unit is under the driver's seat. Remove the seat to gain access. Locate the wires coming from the door lock cylinders - lock(brown/white), unlock(brown/red), and trunk release (blue/black). The immobilizer activates these functions when the lock cylinder turning causes them to ground out. So, follow the wiring diagram on your new lock system to splice in the wires for a ground activated setup (vampire clips or posiclips work fine.). Voila. New remote.

A few additional things here. I have not done this yet so I can't personally verify that it works (yet). Second, this method of locking and unlocking emulates you turning a key in the door. Do not use the wires from the central locking switch - I'm pretty sure that these will NOT activate/deactivate the alarm system itself. Lastly, the colors I wrote above SHOULD be correct for MY2000+ but it has recently come to my attention that the 986.2 (03-04) cars have differences in their wiring schema and to the best of everyone's ability, no one has found wiring diagrams for those years.

Happy hunting!

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[ike84]

Btw, I just came across this. See point 2.

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[pilot4fn]

Originally Posted by ike84

Btw, I just came across this. See point 2.

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Hi Ike,

Couls you post a bit better quality image of the post. Currently it is almost impossible to read the text (at least for me) regadless if I zoom in to the image

[ike84]

Sorry, image quality is limited by Tapatalk. What it says is that if the remote gets operated out of sync from the car more than 256 times but less than 1024 times it can be recovered with the following procedure:

Start the car with the key
Shut down the car and remove the key
Use the remote buttons within 5 seconds.

This should reset it. I seem to remember reading somewhere that if you exceed the 1024 mark then all hope is lost and the link is permanently broken. It's odd that the numbers correspond to numbers of significance in binary coding, which probably has something to do with the rolling codes that the remotes use.

I've not done this to know if it works or not. If anyone has success with it please let us know.

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[pilot4fn]

Originally Posted by ike84

Sorry, image quality is limited by Tapatalk. What it says is that if the remote gets operated out of sync from the car more than 256 times but less than 1024 times it can be recovered with the following procedure:

Start the car with the key
Shut down the car and remove the key
Use the remote buttons within 5 seconds.

This should reset it. I seem to remember reading somewhere that if you exceed the 1024 mark then all hope is lost and the link is permanently broken. It's odd that the numbers correspond to numbers of significance in binary coding, which probably has something to do with the rolling codes that the remotes use.

I've not done this to know if it works or not. If anyone has success with it please let us know.

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Thanks

[pilot4fn]

Originally Posted by ike84

Sorry, image quality is limited by Tapatalk. What it says is that if the remote gets operated out of sync from the car more than 256 times but less than 1024 times it can be recovered with the following procedure:

Start the car with the key
Shut down the car and remove the key
Use the remote buttons within 5 seconds.

This should reset it. I seem to remember reading somewhere that if you exceed the 1024 mark then all hope is lost and the link is permanently broken. It's odd that the numbers correspond to numbers of significance in binary coding, which probably has something to do with the rolling codes that the remotes use.

I've not done this to know if it works or not. If anyone has success with it please let us know.

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Tried this with both of my keys with no success.

Also, I had the car at the local Porche dealer and they could not get either keys to communicate with the car. Car is US spec and has M535 alarm.

What could be the issue here

[ike84]

I really don't know. These remotes are wonky. I gave up in mine a long time ago, hence why I know how to install that aftermarket controller

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[stateofidleness]

just recently had same issue, but all I had to do was turn the key to the "On" position (don't need to start the car), then turn it off. And that synced my fob after a battery change.

[magno_grail]

You should list the model number or year when posting about re-syncing the remote. From what I have been able to determine, the 986 does not use the rolling code and the On-Off-Remote button does not work. I think the 987 (2004-2012) does.
The remote and starting/unlocking/alarm are different systems. The remote just tells the CLU to lock/unlock the door or trunk (and sets the alarm by locking/unlocking the door). The RFID pill in the key lets you start and the mechanical key in the door locks/unlocks/sets the alarm.
Be grateful you have a mechanical key. A recently acquired Volvo (a real grannie scow) had remote problems. With their "emergency" key (which the dealer wants $200 for) you have to pry off the lock cover to use. You think having to open the trunk by the inside latch is an annoyance.

[ike84]

Originally Posted by magno_grail

You should list the model number or year when posting about re-syncing the remote. From what I have been able to determine, the 986 does not use the rolling code and the On-Off-Remote button does not work. I think the 987 (2004-2012) does.

The remote and starting/unlocking/alarm are different systems. The remote just tells the CLU to lock/unlock the door or trunk (and sets the alarm by locking/unlocking the door). The RFID pill in the key lets you start and the mechanical key in the door locks/unlocks/sets the alarm.

Be grateful you have a mechanical key. A recently acquired Volvo (a real grannie scow) had remote problems. With their "emergency" key (which the dealer wants $200 for) you have to pry off the lock cover to use. You think having to open the trunk by the inside latch is an annoyance.

Magno, what you said is not accurate. The 986 immobilizer system does use a very advanced (even by today's standards) rolling code system to communicate between the fobs and the immob. This is why the keys can become out of sync with the unit and programming a new key requires the iPas codes to sync the new transponder to the system. The immobilizer is responsible for control over ALL security aspects of the vehicle. There are not separate pieces of the system, it is a single piece of hardware utilizing encoded programming to interpret signals from multiple inputs and correspondingly run several different routines through multiple outputs under specific circumstances. The closest thing anyone has come to hacking or bypassing the system on the user level is installation if aftermarket remotes. ECU doctors claims to have reverse engineered the hardware and broken the software encryption but I can't speak to that further because I don't have any first hand knowledge beyond what they've published online.

All of this is detailed in the owners manual, the FSM (which is where the "on-off-remote" technique screenshot I posted came from), and wiring diagram. If you (or anyone else for that matter) needs copies of these materials, I'm happy to provide them at the low low cost of free-99

This will come off as dick-ish but please don't speculate based on what you know of the 987s. I'm really not trying to he harsh, it's just that the system is confusing enough to understand and it makes it difficult if misinformation gets posted.

On the other hand, I feel you about the Volvo situation. My uncle used to have a Volvo S80 (bad ass sedan during it's time... That was the first car I ever got over 110mph lol). We were golfing one time and he locked the keys in the car and his clubs in the trunk. Talk about a cluster****************!

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[magno_grail]

The on-off-remote button does not sync a '98 or '99 by experience. The reference to the 987 difference comes from searching the internet which, as you can tell, has a lot of bovine excrescence on it.
Not a very advanced system if a key becomes out of sync because it is not used for a while.
I have the Bentley manual for wiring and simple repairs. I went through all the immobilizer wiring when it went belly up from water ingestion.
From experience, if you change out the EEPROM from the old immobilizer to the new one you do not need to have a "dealer" program it.
Maybe sometime when I have nothing to do I will put a logic analyzer on the EEPROM and see what is being read from it. I presume when a key is inserted, the FPGA reads the list of stored RFID keys and compares them to the signal from the ignition switch. Then all I have to do is read the code from the non-working key and program it into the EEPROM list.
Same with the immobilizer/DME. They claim the immobilizer can only be programmed once but the name EEPROM says it can be programmed many times. The FPGA programming is what keeps it from being reprogrammed. The immobilizer checks the code programmed into the DME with what is in the EEPROM.
The immobilizer controls all the security but the radio remote and RFID pill are separate inputs. You do not need a remote to start the engine but you do need the RFID pill. The pill will not unlock the car but the mechanical key will.
If someone is going to steal a car they will just put it on a trailer. More typically it is smash and grab.
I find the annoyances of a remote outweigh the advantages.

[ike84]

I agree that it's crazy they can become out of sync. It's because each time the fob is used, the immob sends a new code back to the fob to be used the next time. I don't know what the algorithm used is but it seems sequential to me based on the fsm saying that they can be resynced within a certain number of"cycles" , although I dont know of anyone who has successfully done this.

I'd be surprised if the eeprom dump isn't encoded. If it isn't and you find a way to reprogram old fobs back in you would be a hero to a lot of people!

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