Central Locking problems

Hi I'm having some inconsistent operation of my 1997 9000 CSE's central locking system. I have not owned the car long yet when purchased every lock was working. Not long ago the front passenger lock stop working. I removed the door trim and lubed the actuator and inspected the plug. I bench tested the actuator which worked fine. Replacing this seemed to fix things for a short time. Now however the central locking has stopped working on all doors. When the locking button on the central console, key button or driver door key is activated I can hear clicking noises from the doors but no door buttons move. Does this sound like a problem with the relay? If it is the problem how do I identify the central locking relay? I assume this is located behind the fuses on the front passenger side?
I did find that the fuse which is labelled both for the interior lights and central locking blew the other day. I have replace the fuse and the interior lights are now working but the central locking isn't.
Thanks in advance for any advise.

[FONT=verdana]Central locking control module is a problem I've seen in multiple 9ks. Mine is inconsistent as well, it decides in the morning whether its coming to work that day or not. One day, it will work perfectly all day - lock via the key fob, lock/unlock via the center console - but then next day, hey I won't lock all your doors when you hit the lock button on the fob, I won't lock any doors when you hit the button in the center console.

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Originally Posted by Some Guy, Can't remember where I copied it from

Look under the dash LH side (outboard of the steering column in US). It is a black box about 2" X 5" held in place by a gold clip. Pull the clip the box will come free with a twist. Pull the harness clip and you are looking at it.

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If you need another one, $50 bucks isn't too bad.

ePartsLand - Saab 9000 Central Locking Control Unit for Locks 93-98 4102851
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If you're getting intermittent failure of the central locking ECU to do its thing, you probably have bad solder joints on the circuit board. It's easy to fix. Just remove a few panels in the left footwell (non-UK/JP) above the clutch pedal and find the plastic box with a wiring harness plugged into it. It should be held up there by a metal clip that engages a peg holding it in place on a piece of sheet metal in there. It's a black plastic box with the name KIEKERT printed on the side. Good. First one I ever did was crouched on a curb in the rain in the dark the seedy part of Burlington. Cars just like to break there.

Now open the box and you'll see a single circuit board. Remove it and look for the several large black relay-looking things on one side. These have pins with solder joints that tend to crack from old age. Get some nice electrical solder and a soldering iron and resolder them. While you're at it, look for any other suspicious joints, and re-solder them too if you see any.

Re-install the unit and tell me that doesn't fix it! It's pretty easy, fun, and a soldering iron (if you don't have one already) will cost you less money than a new lock ECU, plus you'll have a soldering iron after.

Hi Euromobile900. I haven managed to disconnect the ECU and open it up to check it. Inside the circuit board looks good. I couldn't see any bad soldering or joints. I cleaned the connection points in the plug area and put it back. Unfortunately the problems is still occurring. I had another fuse on the Central locking circuit blow, so something is having some problems. I have a replacement ECU coming soon but is there any other culprits I need to look at to isolate the problem?

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Originally Posted by Antony B

Hi Euromobile900. I haven managed to disconnect the ECU and open it up to check it. Inside the circuit board looks good. I couldn't see any bad soldering or joints. I cleaned the connection points in the plug area and put it back. Unfortunately the problems is still occurring. I had another fuse on the Central locking circuit blow, so something is having some problems. I have a replacement ECU coming soon but is there any other culprits I need to look at to isolate the problem?

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I did the same thing with my ECU. Couldnt find any bad solders, but i cleaned the pins in the contact, but it didnt help much.
Did you have any luck with a new ECU?

Usually I find that "A" door lock actuator has shorted out internally and takes down the central locking system. The process isn't fun - but rather simple. Unplug 1 at a time until the system remains working. The weak link then is replaced.