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Car won't lock

Joined
8 Jan 2018
Messages
6
Morning!

Wondering if anyone has come accross...and fixed...this problem before?

After the battery went low on my 2001 3.4 996 (it drains quickly) I now can't lock the car with the fob or manual key. It locks, beeps, then unlocks again.

It all started when I unlocked it with a low battery. The drivers door opened, but the passneger door didn't unlock. Since then it won't lock at all...almost as if its brain is muddled up.

Tried all sorts, including disconnecting battery and locking/unlocking in various sequences and with the switch while inside (that still works fine).

Many thanks
 
Centre armrest cubby lid microswitch?
 
I had the same symptoms recently. Check everything including armrest cubby is properly closed first.
Mine needed a new passenger side door lock actuator (135 quid plus vat). Apparently they have a two stage locking system and if the deadlock doesn't work it'll have this symptom.
 
:yeah:

I'd say it will be this too. Especially if you've double checked all the other locking points are closed properly.

My passenger door lock failed and it did what you describe, car would try to lock but locks would spring open again and you'd get the double beep of horn.

I bought a used tested one for £35 and fitted it myself. Easy job. Careful with the door membrane though. Rip it and it's £50 for a new one.

If your Indy is local he can plug his laptop in and pin point it. :thumb:
 
Good to know I'm not alone. Thanks for the pointers...I'll try the cubby again first, but had a feeling I might be taking a door apart again.

Infact I'll be taking both doors apart, as the winder mechanism on the drivers side went twang this morning when the window tried to drop. It was frozen up with the ice/snow. Doh! It's MOT day today too...but turns out working windows aren't needed for a pass.
 
Question has been answered really so not a lot i can add .. if the car beeps then its to tell you something is open .. boot / bonnet glove box or center consol lid not shut .

It will still lock though .

For it to unlock then its being told to unlock .

LHD cars and the key barrel is on the passenger side .. thats the bit i think has broken .. its just a micro switch in the lock assembly .

That could be stuck in the open position so even though the lock function is set via fob or key it sees an unlock from the passenger door lock assembly and follows that command .

996 is a pretty basic system which relies more on micro switches and relays than codeing so it doesnt get confused as such like a 997 could .. there is a small amount of codeing / software but not really for this sort of thing .

A tester connected to the car will be able to identify the fault in 5 mins or so .. looking at the lock switch values when its locked will soon say which item is at fault .

----------------------------------------------------------------------------------

Just a point to make but for a drivers lock replacement ..

If you undo and pull down the lock with the wireing plug connected then the key barrel part will twist .. that will operate comfort open / close and the window will usually drop .. as your hand will be in there it can get messy .

I only did this once when i was new .. never again .. you have been warned peoples :)


BTW .. i started work as an apprentise in 1981 :D
 
OP did you solve your issue?

I have taken both my door locks out for testing as I have some strange goings on with my passenger door (locks on the key but won't unlock unless using the interior pull handle) and can report the following findings.

The mechanical parts of the door locks on my car (vw stamped parts) are full of crud and as I split them away from the electrical sections I simply washed them in petrol and used a blow gun to dry off. Catches, springs etc have been re greased and operate much better.

I've opened up and tested all components in the electrical sections and found the drivers side one to be ok (tested all micro switches) but inside the passenger one the cam which operates off the second motor and bears on one of the micro switches to indicate if the door is locked or not was seized. As its plastic I carefully removed it and used some fine wet and dry rolled into a tube shape to open up ID and re assembled with a blob of grease and I think this was the cause of my problems though I've yet to get them back into the car for testing.

One thing I did note the micro switches that indicate if the doors are open or not are becoming quite worn, they bear on the keep plate of the lock and tent to groove the plastic coating on this as well as wear down. I think they could be repairable but shall leave alone for now.

I will try and add some pics of this for ref

:thumb:
 
Finally managed to find time (and nice enough weather) too look into the locking problem, so thought i'd update...main headline is I seem to have fixed it.

Stripped down the passenger door and pulled out the lock mechanism, then separated the electric part from the mechanical. Next opened up the electrics to have a look for anything untoward.

Had previously done this on the drivers side, and found a dry joint on the circuit board. Soldering this up fixed the problems I was having with that door.

On the passenger side all the joints and micro switches were fine, so pulled the connections from the motors to test them. That's when i noticed one of the motor connections looked a bit suspect.

There are two pins that slide into the ends of each motor to connect them to the main circuit board. Inside the connections on the motors are little copper tabs, which should push against the sides of the pins (just like in a wall plug). On one of these, rather than the pin sliding into the connector, it had crushed the copper tab down.

Took plastic cover off the back of the motor so i could straighten out this copper tab, then put it all back together. There were also signs of oxidation on the copper where the bad connection had been.

I can't say for certain that the poor motor connection was the problem, but it all works again now :)

Can only assume that either someone had taken it apart before, or it had been like that from the factory. Either way it would have been that way since before I bought the car (over 9 years), so it's taken a while for connection to degrade.

For info the mechanical part of the lock was all fine; nothing sticking or corroded.

Now I've posted this, i bet it'll start playing up again :)
 
So there's one more problem to sort now.

The passenger window won't go up to the closed position until I lock the car.

Was ok at first, but then the other day it suddenly dropped while I was driving along.

Maybe there is a micro switch problem somewhere after all :/
 
The car needs to know the passenger door is closed to roll up the window .. the micro switch for that is in the passengers door lock ass. the bit you stripped to check im afraid .

I suspect that might be the fault .

With faults on the alarm / locking system then a tester and looking at the values for every switch is the best way forward .

Its a 10 min diagnosis with a tester to see which switch has failed .
 
So I managed to have another look, and couldn't find any faults with microswitches (electrical or how the mechanisms moves to contact them).

However, that motor connection I mentioned before still seemed a bit weak. Bending the terminals slightly, and adding another layer of foam padding to the small patch in the housing (this pushes against the connections into the motor) appears to have fixed the problem properly this time.

I'll be honest, in bending the terminals I did break one off...but managed to use a cut down crimp terminal to save the situation.

It's been ok for a few weeks now, but I've left the door panel off just in case :)

Next job...front to rear brake lines :/ Should be fun!!!!
 
If you do need to replace it, it's the same as the upmarket Audi TT and you can get the part much cheaper from ECP or other suppliers than from Porsche.
 
Does anyone have a part number or link for the audi part. I've got an intermittent double beep problem.
Cheers Guy
 

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