Door locks and the double beep?

My 996 has developed the double beep on unlock thing. The doors both lock and unlock OK with the key and the remote but clearly the car's brain is unaware of the correct status. I know there is a problem with a microswitch in the latch but is there any way (easy way) to find out which side is the problem? Thanks C

It's a bit of a guessing game as there are many sensors which could be at fault. First check, bonnet, engine bay lid and centre console glove box are closed properly. After that, I replaced both door latch mechanisms which fixed it. The drivers side was quite worn and made the issue much better, but I still got it occasionally, until I also did the passenger side. There's a plastic round wheel/cam which pushed a microswitch in the latch mechanism. The wheels were worn on both and the plunger on the microswitch was also worn on mine. My early 98 Cabrio could use some Audi TT ones which only cost me £30 or so each. These seem to be harder to find lately. It needed to be the one with the correct number on pins. Can;t remember if it was 7 or 9, but the listing specified these worked with an early 996.1. It was too long ago for me to find though.

Yeah I checked the boot etc but that's not the problem. They will give a beep on locking if they are faulty, so I'm sure it's the doors but I was wondering if there was left/right specific ODB codes or similar to identify the culprit and improve the 50/50 odds of fixing it first time? C

I've had this issue before, mine was when I fitted a short shift kit. The sensor under the handbrake/gearshift cover had worked its shelf loose. Might be worth a try if you have had it off?!

I doubt standard OBDII will be able to. I've never looked in PIWIS, as I didn't have it when I had this issue, but that should be able to tell you the locked/open/closed status of the various microswitches in the door. or which one the alarm is beeping the horn for.

TYPICAL FAULTS may not be related in your case but useful to know. All these microswitches can be problematic, and it is common for one or more to fail at some time. These are some of the common failures and symptoms: 1) The door window won't drop when lifting a handle. This is usually the handle microswitch which has failed. 2) The window drops, but goes back up when the door opens, or when the handle is released. This can be the handle microswitch, or more likely the 'door open/closed microswitch has stuck. Because the system thinks the door is still closed, it sends the window back up. 3) Door window won't go up the last 10mm. This is likely to be the 'door open/closed microswitch stuck in the opposite sense to (2). The system thinks the door is still open, so won't allow the window to go back up. Note that in this case the door will still lock, but you may get a single-beep from the alarm horn. 4) Door will not lock with key. The 'key lock' microswitch is broken. This is very rare, as this microswitch is hardly ever used – most times the car is locked by remote. 5) Door will not unlock with key. The 'key lock' microswitch is broken. This is also very rare, for the same reason. 6) Door locks, and then immediately unlocks, usually accompanied by a double-beep from the alarm horn. This is the 'door locked' microswitch.The locking motor physically operates the door lock, but the microswitch to sense this has failed/stuck. The ACM promptly unlocks the car. In this case, the only way to lock the door is to use the emergency locking procedure. Turn the key in the door to the lock position and back three times in quick succession. 7) The door unlocks, but there is a beep from the alarm horn. This is the 'door unlocked' microswitch . Although the door is unlocked, the ACM has not recognised that. The alarm will not sound, as turning the key in the lock has deactivated

If the car was presented to me .. A tester on it .. look at actual values for All the switches , locks etc .. the fault is usually pretty obvious from just this but i would also look at the event and actuation list .. One is a list of things the car has seen when locked .. the other is a list of things that triggered an alarm .. the last 10 events basically . In short i like i expect many many other Indys could diagnose your fault in about 20 mins .. you would be charged 0.5 so about £50 . Your issue will be one of the door locks or rather the micro switch saying the door is secure locked when its actually open . Either get a suitable tester on it or book it in please as its far cheaper than just replacing parts .

Thanks for the responses. The problem is not quite any of the options listed above. Both doors actually lock OK with either the remote or the key. Both doors unlock OK with either the remote or the key but in every case the unlock is accompanied by a double beep. So this is not the biggest problem to deal with at present but it's probably going to get worse in time. It is clearly a micro-switch fault and if I can get a sufficiently good tester I can at least identify which side is faulty. C

Single beep is the car telling you something is open on locking .. you don't get a single beep on unlocking . Double beep is the car telling you there is a fault on unlocking or locking .. It can't be cubby hole switch , glove box , boot or bonnet etc .. you are pretty much left with door locks , drivers door key switches ( which give other issues ) inner / outer door handle switches ( again other issues ) so we can pretty much nail it down to one of the door locks is saying its still in secure locked when it isn't . 50/50 as a guess hence a tester on actual values will show which one . Just my thoughts anyways .

Mine had the exact same symptoms a few months ago. I thought was a micro switch. Despite the battery appearing to be charged up, I charged the battery up on my cTek for a couple of days and the issue went away. Hoping the same could be the case for yours.

mine did the same when i first got it, it turned out to be something behind the stereo something to do with the earth cable from memory