Simonm1

Hi my name is Simon I'm new on this forum and hoping some one can help me out here. I've got a 91 964 and I'm having problems with the doors not locking from the key or the lock button inside. I've replaced the main Ecu under the drivers seat and checked the micro switches on the locks. Is there any thing else I should look for. Sorry about all the questions in my first post but this thing is starting to get the better of me and any info would be great fully appreciated thanks in advance

FeralComprehension

What happens when you hit the lock switch or turn the key in the lock?

Simonm1

All I get is a tiny click from the Ecu but nothing else happens the locks will push down and lock freely and will open with the key but not by using the actuators

ToreB

The Motronic engine control unit is placed under the driver's seat, this is not involved in the door lock operation.
Do you have the 993-type of lcok/alarm control unit? This is a metal unit placed under the passenger seat, equipped with a yellow and a black connector. This has a fuse inserted between the connectors, you could check if this is OK.

Early 964 models have a more simple lock control unit placed in under the dashboard in the passenger foot well. Maybe the connentor has been kicked out of the socket?
Cheers,
Tore

Andy Roe

Simon - is your car right or left hand drive? (Just so we know specifically which seat you're talking about).

Simonm1

Sorry my car is a rhd I've replaced that Ecu and the fuse also and still no joy iirc a 15a fuse between the two plugs. Thanks for the replys guys

Masher

The actuators are not operating at all? Sounds fundamental.

A more common issue is the actuator works but the lock does not. This is often down to a broken pushrod in the locking mechanism (plastic ball and socket joint where the socket is broken) - easily checked by taking the door card off.

Since there are several ways to lock and unlock doors it might be worth updating us on whether any of the following cause an actuator (either door) to work:
1. Remote keyfob type alarm / central locking
2. Key in the drivers door - I THINK this should operate both doors (someone will correct me if I'm wrong)
3. The central locking button on the centre console

If none of these operate an actuator in the door then you have a fundamental issue UNLESS the car is new to you and has done this since you got it in which case you could have 2 x actuator failure but with no history you would not recognise this double fault.

Best of luck.

boxsey911

As Tore mentions above there is a relay between the ECU and the locks actuating. On a RHD car you will find it in the passenger footwell attached the firewall. You'll have to move the seat fully back and get your head right in there to find it. It's a grey box about the size of *** packet.

Mine partially failed so that only one door would lock. Replaced it with a used one (off a 944) to fix it. They're about £350 for a new one.

Simonm1

Thanks I can see that grey box under the dash is it likely to be that one gone. The actuators are moving freely in and out and all linkages are fine no stiffness or broken/bent rods. It's been like this since I got it. When I turn the key in both doors the Ecu clicks but nothing else can any one tell me which connections I should get signal to on the actuators when triggered by the key maybe then I could test the actuators manually with a 12v supply

Simonm1

Any body got any pin info on the door actuators thanks

ToreB

Both sides are identical.
Cheers,
Tore

Simonm1

Brilliant thanks for that it should be some help in figuring out what I need from each pin

LM964

Any luck Simon? Been watching with interest as I have the same issue but not got round to that to-do list yet. However, hasn't bothered me too much if I can still set the alarm and imobiliser. Would be to find out if you sorted it...

boxsey911

Simon and Marcus, the information in my own old thread about central locking problems might be useful to you:

https://rennlist.com/forums/964-foru...g-problem.html

LM964

Good man Steve. Bookmarked for my winter workshop romp...