Central Locking Pump failure (solved) and prevention

[937carrera]

Last night I came home and found that the central locking was no longer working on my Polo.

After reading around I checked fuse 41 and found that to be in good condition, so then knew I needed to look at the central locking pump located just in front of the right hand rear lights.

I disconnected the electrical connector and found evidence of corrosion, not surprising as there was water on the outside of the pump unit.

I then squezzed the pneumatic connector to disconnect it from the pump, unclipped the white plastic cover and pushed through the 4 rubber grommets that hold the pneumatic componenets in place and carefully levered the circuit board out.

It was not a pretty sight, with a build up of blue crusty corrosion around one of the IC's and some of the resistors. With nothing to lose I sprayed the circuit board with WD40 (not contact spray) and brushed the corrosion off with an old toothbrush. I then used a hair dryer to dry off the remaining WD40 and reassembled after cleaning the terminals and connector block.

It worked

After getting it working again, and realising that water leaks from the back light seem to be a common fault, I then wrapped the central locking pump in cling film to help prevent future water ingress. I'll look at stopping the water coming into the car later.

It's a fairly easy job, taking about 30 minutes in total and wrapping in cling film could be good preventative maintenance

[alexperkins]

Common fault this. Rather annoying too. Easiest way to stop it happening is to bring the CL pump forward into the front section of the rear pocket so its away from the rear lights themselves

The rear light seals are made of a neoprene rubbery foam - normally a quick clean up and a smear of silicone will stop them leaking

[937carrera]

Mine was already in the forward section

I'll remove / refit the rear light at the weekend. Having changed a tail light last week I'm not happy that the bottom part of the bulb holder assembly is correctly seated in the lens section and it'll be a lot easier out of the car

Cheers

[patton]

brilliant!! thanks very much for sharing this! I've got about 4 pumps lying about that don't work so i can get them all fixed now and sell them on

[937carrera]

Happy to help, please let us know if you manage to get on with resurrecting all four pumps

I removed the rear light last week. The "difficult" outer nut did not seem to be fully home so I suspect someone had removed it previously and not quite put it back in correctly. I also discovered that the prongs simply sit on top of the posts, which is where i was getting it slightly wrong when trying to refit the bulb holder

[Bhanayk]

The beauty of forums... My central locking isn't working but I'm glad I've come across this post. Thanks for the solution, going to give this a go this week. Fingers crossed it works.

[Patchjay96]

Been out all day and every time I come to my car it's windows are down an my kees unlocking itself, then when I get home only driver door is locking, I came across this and gave it a go, my pump had quite a lot of crap on it and cleaned the circuit board as instructed and it's working wonderful now , took less than half an hr. Thank you

[937carrera]

It's a pleasure, and always nice to get the appreciation. Mines still working fine over 3 years later too

Thanks