Central Locking

I have a problem with the central locking but before I go stripping things down I thought it best to tap the extensive knowledge out there! When I lock my car the horn double beeps. The fault is showing as the passenger door catch according to computer analysis. The paasnger door hasn't locked, hence the double beep. If I then open the passenger door and close it and again lock the car again it locks okay and no beeps! If it wasn't locking at all then I would be looking for a fault with the mechanism or motor but the fact that it does if I go through the above actions is very confusing. Any ideas???

Most likely a sticky microswitch in the door handle assembly - there are 7 switches in each door! You can get the PST2 to display the state of the switches, so it would be worth plugging it in again, and see which one is behaving oddly. If I am closer to you than Tony, I'd be happy to give it a go for you.

Richard, thanks for that. I'll have a play but may well end up taking your up on your offer! I don't recall the PST2 displaying which switch, although I could be wrong.

The fault code will tell you what the gerneral fault is, but if you look at the input signals to the control unit for each switch then you should be able to track down which one it is. There are 2 switches in the handle, and 5 in the door lock assembly. I expect it is one of these 5 - the one which is telling the control unit if the door is locked or not. Unfortunately, if this is the case, you have to replace the complete lock unit, the cost of which is between £85 and £100. (Ask me how I know....)

That's cheered me up Richard! What baffles me is that it locks after I have opened the door and closed it again. I must admit to being somewhat more comfortable with mechanical matters than electrical.

The car goes into sleep mode to save battery. It's an energy saving feature and is normal. You have to use the key to unlock the car, whereupon it'll wake up and you can then use the fob to disarm the alarm

Hi Neil A single beep from the alarm horn usually points to something not shut correctly, either the glove box on a Mk2, oddments tray in the centre console, door open, fuel cap, luggage compartment or engine compartment being left open or one of there switches has a fault. A Porsche tester will be able to find the culprit but The following links may help you find the issue. Good luck Andy https://www.porscheclubgb.com/forum/tm.aspx?m=570901 https://www.porscheclubgb.com/forum/tm.aspx?m=685707&high=central+locking

When you lock the driver's side with the key, does the passenger side actually lock? If it doesn't, then it is probably the fuse for the central locking, which is located between the two connectors on the alarm unit, located under the passenger seat.

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If you move the seat all the way forward, and adjust it as high as possible, you should be able to reach the fuse from the rear footwell. The two-wire connector is probably the one for the seat belt deactivation kit (for the child's seat). It is usually taped to the underside of the seat, but they often fall down.

Hi Richard, Finally managed to get to the fuse, had to remove the seat but got there. The 15 amp fuse is fine it had not blown, anything further I can check? Regards Neil

Any sign of dampness around the alarm module? When you lock the car with the key in the door, do you do it with a single turn of the key? Does it lock the passenger side when you lock the driver's side?

Hi Richard, No dampness around the unit, when I put the key in the drivers door I turn it to the left once and it make a single beep. The passenger side does not lock. Regards Neil

That's exactly the symptoms of a blown fuse on the alarm module, so I'm surprised you found it to be intact. That fuse powers the central locking part of the alarm module. The rest of the system must be working, otherwise you wouldn't be able to start the car. (The immobiliser wouldn't be working). You could double-check the fuse, but apart from a bad connection on one of the plugs, I can only think it must be an internal fault with the alarm module.

Hi, I have replaced the fuse and checked that the connectors are pushed in but still no luck. Will have to get the alarm module checked out. Thanks for your much needed help. Regards

Which model/year are you asking about? This can then be put in the appropriate forum.[ ]

Thanks for reply it's 911/996 C4 soft top

HI Nigel. If you have one good working key then it should be possible for it to be replicated. It could also be dodgy switches in the remote. Depending where you are in the country there should be an equivalent to the guys on the following link. I have used then (not on a Porsche, but to get a replacement immobiliser / key). Had excellent service, give them a call, if there too far away they may be able to advise on someone in your location. KeyLad in Milton Keynes Auto Locksmiths Milton Keynes | Keys-Diagnostics-coding (thekeylab.co.uk) Good luck Andy

Moved to 996 forum

Thanks Andy there is Harolds in Sheffield who put a new micro switch into the key that is working (when it wasn't ) that's the one working now (£10 ). Took this one in and they advised Dealer , I'll go back to them with that information and see what they can do. I'll let you know.