Technical Intermittent central locking problem

[Sverige]

Hi all

my 2000 punto mk2 188 5 door has a problem which showed up for the first time today. After driving the car and jumping out, only the door into which the key was inserted and turned locked. The other doors remained unlocked. This was tried on both front driver’s and passenger’s side, and only the door I was locking actually responded.

Then after driving a short distance it was all back to working normally, and the key locked and unlocked all four doors, so it’s something intermittent.

Does anyone know what can cause this? Today is the first cold weather (0C) so maybe there’s some thermal element to this problem - a loose connection showing up just because a wiring loom connector shrank a tiny bit, perhaps? Logically, if it’s affecting all four doors it should be at some central control until under the hood / bonnet, rather than within the doors themselves - anyone know where this unit might be? Then I could try just unplugging and replugging the wiring loom connector, maybe with a squirt of contact cleaner for good measure?

 

[judderbar]

Presumably you are saying the button on the door where the key is being used does not jump up and down when the key is turned? You are saying the system is totally not working?

I think you are right to think it could be a plug. The control unit is part of the passenger fuse box. All the central locking plugs are found there.

 

[Sverige]

Presumably you are saying the button on the door where the key is being used does not jump up and down when the key is turned? You are saying the system is totally not working?

I think you are right to think it could be a plug. The control unit is part of the passenger fuse box. All the central locking plugs are found there.

Yes, the button on the door does not operate, neither does the door lock, on all doors other than the one the key is being operated in. Thanks, I’ll start my search in passenger side fuse box then.

 

[Sverige]

Presumably you are saying the button on the door where the key is being used does not jump up and down when the key is turned? You are saying the system is totally not working?

I think you are right to think it could be a plug. The control unit is part of the passenger fuse box. All the central locking plugs are found there.

Hi, by passenger fuse box I guess you mean the one in the passenger compartment, not passenger side of car? The one in attached screenshot?

I see fuse 38 for central locking, but no central locking control unit in the layout diagram. Is there anything which might help me locate which connector in that vicinity would relate to central locking?

 

[judderbar]

yes it is on the drivers side on a left hand drive car. Your fuse box is different to my one. All the cables are uniquely colour coded so if you find the hole where the cables come in from the door that would be one way to find the plug. But it is not so hard to disconnect the plugs.

 

[Mike1alike]

You should try putting some cleaning spray where the key goes into the door. Then keep locking and unlocking it. That must make it work again, then put some lubricant (spray) into the key hole. Do this for both doors. This is how I've fixed the exact same problem at my Punto.

 

[Sverige]

You should try putting some cleaning spray where the key goes into the door. Then keep locking and unlocking it. That must make it work again, then put some lubricant (spray) into the key hole. Do this for both doors. This is how I've fixed the exact same problem at my Punto.

Thanks for the tip, I’ll try this