Porsche 996 central locking problems
Discussion
I have a 1999 Porsche 996 C4 and central remote locking never been that good for two years since owned it, seemed like you had to almost stand next to car for remote activation to work. Now remote does not work at all (yes changed batteries on both fobs!) and manual key opening sets off alarm after 10 seconds (as normal) until ignition turned. However, manual key opening does not operate the passenger door at all so have to open from inside and the locking button on dash does not open the door either. Not too much of a problem as passenger door not very far away from drivers seat! But this is annoying. Any ideas on a fix or is it off to the dealership?
Ah ok, sorry I didn't pick up on the both fobs thing when I first read it.
I wonder if you're looking at two separate problems here - the central locking receiver not picking up the fob signals, and then a mechanical error with regard to the passenger door and the dashboard switch?
There may be a fault in the system somewhere. Don't suppose you get a quick 'beep' from the alarm horn when you lock it do you? If someone has disconnected it, the other ways of checking for faults are that after locking you get double flashes on the red dashtop lamp, and also after locking the interior light comes on brightly and stays on for a few seconds. Both these things indicate alarm / central locking faults.
Go have a look and report back when you've locked it.
I wonder if you're looking at two separate problems here - the central locking receiver not picking up the fob signals, and then a mechanical error with regard to the passenger door and the dashboard switch?
There may be a fault in the system somewhere. Don't suppose you get a quick 'beep' from the alarm horn when you lock it do you? If someone has disconnected it, the other ways of checking for faults are that after locking you get double flashes on the red dashtop lamp, and also after locking the interior light comes on brightly and stays on for a few seconds. Both these things indicate alarm / central locking faults.
Go have a look and report back when you've locked it.
Had a play with the car. I found if you lock it and unlock it twice the passenger door now opens so may be a little glitch in the system there.
When I lock it there is no sound from the horn. The interior light does not come on but the red dashboard lamp flashes very quickly 20 times and then goes back to its slow flashing cycle.
When I lock it there is no sound from the horn. The interior light does not come on but the red dashboard lamp flashes very quickly 20 times and then goes back to its slow flashing cycle.
Well with no interior lamp showing and the red lamp slowly flashing like it should, the system isn't indicating a fault.
The usual suspects with alarm and locking errors are the driver's side door lock mechanism unit or one of the internal microswitches. Sometimes it can be the internal sensor pod by the interior lamp but that's unusual.
I think the next course of action is to find a good indy and plug it into Durametric, or PIWIS if they have it, to see if there are any older fault codes stored.
These sorts of things are bloody annoying, aren't they?!
The usual suspects with alarm and locking errors are the driver's side door lock mechanism unit or one of the internal microswitches. Sometimes it can be the internal sensor pod by the interior lamp but that's unusual.
I think the next course of action is to find a good indy and plug it into Durametric, or PIWIS if they have it, to see if there are any older fault codes stored.
These sorts of things are bloody annoying, aren't they?!
nigelsloper said:
If you lock it and unlock it twice the passenger door now opens so may be a little glitch in the system there.
Normal operation via lock barrel, no problemnigelsloper said:
When I lock it there is no sound from the horn. The interior light does not come on but the red dashboard lamp flashes very quickly 20 times and then goes back to its slow flashing cycle.
Normal operation when manually locking. Locking with the remote is the only 'single' lock way of setting the alarm. IIRC double manual locking sets the alarm in the event of a fob failure.Some things to try:
Reset keys - Remove fob battery, reverse and refit, remove again and refit correctly (sounds wrong but is actually a TI bulletin)
Resync keys - Insert key, switch on igntion, press lock button on fob twice (This will resync the key if it has dropped off the list)
There is a TI regarding reception range on certain model year cars, will check on Monday
After that:
Its commonly seen for a pair of keys to fail, I have managed to restore functions using the read / write key function in PIWIS but it's not 100% successful. Two new keyheads are usually the fix.
Thanks Pope, tried the fob fixes but still no joy. Looks like a trip to Porsche in Bournemouth for me. Oh well, nice drive though.
Also, thanks for confirming double locking was normal. Seems that one manual turn just opens the drivers door but twice unlocks eveything including fuel filler cap flap and bonnet/boot lid locks.
Also, thanks for confirming double locking was normal. Seems that one manual turn just opens the drivers door but twice unlocks eveything including fuel filler cap flap and bonnet/boot lid locks.
Don't mean to hijack the thread but I have similar problems on my newly acquired 996. If I have not used the car for a week or two I can only get into the car manually using the key, (which requires turning over the ignition before the alarm goes off). Once I have driven the car it then locks / unlocks using the remote keyfob no problem. Dumb question but can someone tell me does the 996 turn off its reception to the remote if the car has not been driven for a certain time?? That's what seems to be happening with mine. Btw, the car has a new battery and indicates that it has plenty of charge when I'm driving it.
Pope said:
Yep, Alarm will go into 'sleep mode' after 3-5 days depending on Model Year. The system will wake up once you turn the ignition on after you unlock the car with the key - the siren will go off after 15 seconds if you don't switch the ignition on after you've unlocked it.
It's easier than that - unlock with key blade, do not open the door, just press the key button to lock then unlock it again, all woken up again and back to normal, no rush to get the key in the ignition etc. 
thegoose said:
Pope said:
Yep, Alarm will go into 'sleep mode' after 3-5 days depending on Model Year. The system will wake up once you turn the ignition on after you unlock the car with the key - the siren will go off after 15 seconds if you don't switch the ignition on after you've unlocked it.
It's easier than that - unlock with key blade, do not open the door, just press the key button to lock then unlock it again, all woken up again and back to normal, no rush to get the key in the ignition etc. To unlock it without the alarm going off, I have to put the key in, turn the lock to lock, even though it's already locked, take out the key and then use the plipper as normal.
AW996targa said:
Just so I understand, you lock the door with the key (turn it to the left if it is the driver door lock)which wakes the car up, then you unlock it with the remote?
That's what I have to do with mine to unlock it without alarm dramas, yes. It's a pre-facelift 2001 C4 though, later cars might be different. I say, just try it with yours and see!Ray Luxury-Yacht said:
See, it's funny, cos if I unlock mine with the key when it's in sleep mode, the alarm goes off.
To unlock it without the alarm going off, I have to put the key in, turn the lock to lock, even though it's already locked, take out the key and then use the plipper as normal.
Some cars managed to have their left and right door wiring mixed up (wired as LHD from build) - this shows itself with the alarm sounding as soon as the car is unlocked from sleep mode (The ECU sees the wrong door is being unlocked and assumes it is being forced).To unlock it without the alarm going off, I have to put the key in, turn the lock to lock, even though it's already locked, take out the key and then use the plipper as normal.
The wiring from the right and left door locks to the alarm system would need swapping from pin to pin on the alarm ECU. There was a TI on it a LONG time ago - I'll see if I can find it......
Edited by Pope on Tuesday 9th March 17:20
Pope said:
Ray Luxury-Yacht said:
See, it's funny, cos if I unlock mine with the key when it's in sleep mode, the alarm goes off.
To unlock it without the alarm going off, I have to put the key in, turn the lock to lock, even though it's already locked, take out the key and then use the plipper as normal.
Some cars managed to have their left and right door wiring mixed up (wired as LHD from build) - this shows itself with the alarm sounding as soon as the car is unlocked from sleep mode (The ECU sees the wrong door is being unlocked and assumes it is being forced).To unlock it without the alarm going off, I have to put the key in, turn the lock to lock, even though it's already locked, take out the key and then use the plipper as normal.
The wiring from the right and left door locks to the alarm system would need swapping from pin to pin on the alarm ECU. There was a TI on it a LONG time ago - I'll see if I can find it......
Edited by Pope on Tuesday 9th March 17:20
Ive just bought a 996 and my central locking is paying up! If i press the keyfob the door seems to unlock as normal but when you pull the handle the window doesnt drop when you close the door, this then shows as doors locked on the dash! (when press the button the horn beeps and light stays on) Any idea what the problem is and how to rectify this please?
(i have just had a new stereo fitted, could they have messed up the wiring?)
(i have just had a new stereo fitted, could they have messed up the wiring?)
Edited by LiamHenderson27 on Monday 17th May 16:24
LiamHenderson27 said:
Ive just bought a 996 and my central locking is paying up! If i press the keyfob the door seems to unlock as normal but when you pull the handle the window doesnt drop when you close the door, this then shows as doors locked on the dash! (when press the button the horn beeps and light stays on) Any idea what the problem is and how to rectify this please?
(i have just had a new stereo fitted, could they have messed up the wiring?)
Yep, very likely.(i have just had a new stereo fitted, could they have messed up the wiring?)
Edited by LiamHenderson27 on Monday 17th May 16:24
There's a microswitch behind the stereo that's there to activate the alarm in case someone prises the unit out. If another stereo has been fitted, then you need to check this switch. Had this on a mate's 996 recently, sorted by removing the switch and connecting the wires together.
Pope said:
Yep, Alarm will go into 'sleep mode' after 3-5 days depending on Model Year. The system will wake up once you turn the ignition on after you unlock the car with the key - the siren will go off after 15 seconds if you don't switch the ignition on after you've unlocked it.
So what is 'sleep mode' then? i.e. Is it a reduced level of security to save battery or something?Gassing Station | Porsche General | Top of Page | What's New | My Stuff