996 Central Locking System Issues - PIWIS II Capable

I have a new to me 02 996.2 Cabrio and the Key Fob and CLS have ceased to function. Current symptoms: Key Fob blinks but the car does not respond. This functioned up until the battery was replaced. The CLS button on the dash does not function in either lock or unlock. It did have the red LED illuminated yesterday. The passenger door handle will not command the window to move if using the interior handle. Outside and driver�s side do actuate the windows. If I lock with the key, I get the single beep and the alarm will go off upon opening the door with the key. It will silence when using the key to start the car. I have the PIWIS II (clone) and confirm it connects properly, I am just not sure what direction to start as it is new to me. I am new to the 996, but not troubleshooting, as I am a Flight Engineer in the USAF. Any assistance would be greatly appreciated and hopefully it will help someone else down the road. Thanks.

Query the Alarm system module for fault codes . Record/write them down for future reference (but take them with a grain of salt for now) ..... Clear all fault codes.... Operate the car as usual for a period time... Re-test the Alarm system control module for fault codes.....report back with fault codes and description... Other steps :: Lock then unlock the car with the key and within a few seconds insert the key and turn ignition on and press a fob button,, this should synchronize the fob to alarm control unit... Remove alarm control unit from under drivers seat and open it up and check for moisture/water damage...

I cleared the codes from the Alarm Module and the following returned even without starting/driving the car: Fault Code - 12 - Wrong door lock module Fault Code - 21 - W line (DME - immobilizer), open circuit Fault Code - 49 - K-line, short circuit to ground Fault Code - 61 - Central locking limit position safe lock not reached, switch position implausible During the actual values input signals, I can see that the CLS button works and different signals update based on condition, except "Oddiments Tray" and the Remote Buttons 1 and 2 when pressed. The car did beep once when turning the key to the right (aft). I tried all the drive link checks and every thing came back okay and seemed to actuate. Still no response from the key fob. If it remove the alarm control unit, can I re-install it with no special procedures? Unrelated note: When looking through the various other options to get acclimated to PIWIS, I noticed under manual programming for the DME that the exhaust emission standard had OBDII (LEV,Tiptronic) selected vs OBDII (LEV,Manual). Not sure if that is a default starting point, or if it is reading the actual programming information.

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Yes you can remove and reinstall the alarm control module without doing anything but unplug and replug the connector... When programming the DME you have to select transmission type, and also the country/market ect....It doesn't read the current version untill you get to a point that you have to tell it to "read" the current file or "write" the current file...or you can use the a file in the tester to program...It does not do this automatically and in fact will even ask you "are you sure want to do this?" before reading or writing any program... The "read" command is so you can read the files from a damaged DME and "write" them to a new DME.. or if the damaged DME can not be read, you can use the file in the tester to program the DME, but reading the old DME will transfer more information over like VIn and codeing, whereas when writing from the file in the tester you will have to manually enter the VIN and do all the codeing manually...

I�ll try to get to the alarm control module shortly. I have a feeling that most of the errors are incorrect due to the system functioning when I bought the car. Hopefully I can clean contacts and it squared the issue away. I�ll keep the post updated. Thanks!

mine acted stupid in this way out of the blue. Last thig I did in PIWIS was change the alarm version code to version 2 which got rid of all codes except Fault Code 60 (Central Locking limit position Locked not reached, switch position implausible) ... Then, even though I swore it would never work, I put the key fob battery in backwards for a few seconds and pressed the fob buttons. Flipped the battery back in the right way and it has worked perfectly ever since. I know, flipping the battery sounds ridiculous......

I have not removed the module as of yet, but did more tests with the PIWIS II. All the drive link checks will pass when testing. I can get the locks to lock with PIWIS and the CLS button works with no issues for unlocking. PIWIS will report if the CLS button is being pressed in either lock or unlock. I can't get the CLS button to re-lock doors during any tests. When running the System Check, I can get the alarm to activate with all inputs (both doors, front and rear hatches, glovebox) except for the "oddments tray". I have to remove the front seat to get to the alarm module, so I am waiting on enough free time to do so. I cleared the fault logs and got 12 and 61 to come back. I believe that 61 is sympathetic to 12. Based off the current symptoms and not pulling/inspecting the alarm module, can we rule it out? Workshop manual says to replace the passenger door lock based of fault 12. EDIT: I followed the instructions for reversing the battery, but no joy. As always, thanks!

I still haven't pulled the alarm module, but further testing reveals that when locking the driver's door with the key, the passenger door does not lock at all. If I set the alarm with the key, just the function of lifting the door handle causes the alarm to go off.

Pulled alarm module and no signs of water entry of the box or around the area. I did clean the circuit board with electrical cleaner just to be sure. Installed the module in the Specialized ECU waterproof box and the vehicle started. I can still lock the doors with PIWIS II and the CLS button LED acts appropriately, it will even unlock the car, but will not lock it. Still no change on they key fob front. Replaced the battery in the fob with even newer batteries and no joy. Very large pictures attached. I still need to explore the replacement of the passenger door lock actuator, as the same two faults (12, 61) continue to show.

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Your symptoms match mine. I am wondering if pass door lock replacement is the right fix. Thanks.

I have been really slacking on this. The lock has yet to be installed. When I get to it I promise to report back if it fixes it.

This looks a lot like my issue that I�ve rather given up on. You may have inspired me to pick it back up�

Update: Installed replacement door lock for passenger (right hand) side and the CLS button works as advertised, coded locks as version 2 and I get the proper lock after approx 5 mph (or km/h, not sure). Right window drops appropriately from inside and outside. No joy on remotes working. Lights still work in remotes and the little tester things at autozone show a signal. Saw a failure of the reciever in PIWIS III prior to resetting, but that has not reappeared. When using PIWIS III, there is no indication that the alarm system is recieving buttons 1 or 2 from either transmitter (they stay off). If I had the codes, I could try to reprogram the fobs, but alas, I don;t have them. Any suggestions from here?

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I'm hoping somebody might be able to offer me some advice of possible causes and fixes for a problem I have with my central locking. When I activate the locking on my 996 turbo both via remote or key, the locks will turn and then unlock again and beep. I understand this is normal when there is a reason why the car won't lock but normally in the past the car will lock when the process is repeated - now it won't lock irrespective of the number of times that press the remote or turn the key. Has anybody experienced this problem themselves and/or have any suggestions of what the cause of the problem might be? Thanks

microswitch on one of the locks?? (wild guess)

Just a quick update and bump. Central Locking works with no issues, and the vehicle with lock and set the alarm with the key in the door. Both key fobs light up when buttons pressed, I have replaced the batteries in both the fobs and have a new battery in the car. PIWIS does not show a change of status on button 1 or button 2 when depressing either fobs buttons. I tried to heat up the boards in the remotes themselves to hopefully fix any solder issues, but they still don't work with the car, but do indicate and work with the little tester at the auto parts store. Any other troubleshooting other than throwing new key fob remotes at it? Both immobilizer pills work, it just seems to be the electronics on the radio portion.

Bumping this thread with almost the same issues as OP. Just got a 996.2 c4s with two fobs. Neither of the buttons on either of the fobs does anything (just the LED on the fob blinks). I have to unlock the car with the physical key and immediately insert it into ignition and turn to accessory mode or the alarm goes off. The driver door window goes down when the handle is pulled but goes back up immediately after (I'm guessing a microswitch in the door lock assembly). The passenger window is more sporadic -- sometimes it just doesn't go down, and sometimes it works perfectly fine. The center console lock button seems to lock and unlock both doors but also works sporadically. The PPI showed codes 60, 61 (central locking limit position lock/unlock not reached), 46, 47 (control locking synchronization), and 54 (radio receiver faulty). The car still has the stock CDR220. Any advice?

ncster, is your car a convertible?

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It is not. It's a 2002 C4s coupe 6MT.

I think we are now mostly solved. I keep getting a Fault Code 49 - K-Line Short to Ground, but it clears. I ordered a keyfob with code from eBay and used PIWIS3 to add it to slot 3 and now the keyfob actuates the locks and frunk release. It was cheaper than the dealer for sure.