Centeral Locking System..

Memorex944 · Memorex944's Garage

To anyone, I need some help figuring this problem out! I have a Porsche 944 turbo that has automatic locks. They do not work but when Ii hit the button you can hear the central locking mechanism click. I cannot for the life of me figure out if this is a wiring issue, the actuators, or if it is just the central locking mechanism itself. If you believe that you have an idea of what it may be, or just an idea that you believe may work please comment and let me know, I would greatly appreciate it!

Techno Duck · Techno Duck's Garage

The most likely culprit is a broken plastic rod inside the door if you hear the actuators working. The rod connects the actual lock mechanism to the actuator.

Part # is 944.537.511.00

Both of them in my car broke within a year or so of each other. Replacing them is easy, just requires removal of the door card.

aj951 · 05-23-2011, 01:27 PM

Not trying to hijack this thread but I also have a similar problem with my central locking system and thought I might get some help here.

If I push the button on the console to lock the doors, both doors will lock as they should, however, when I push the button again to unlock I hear the mechanism working and the rods near the both windows (driver and passenger) move up slightly but neither door unlocks. I have to physically pull the rod on either door to get it to unlock. I checked the plastic rods that Techno Duck referenced above and they are both intact and connected on each door. Is there some other adjustment to the door/lock mechanism to get the door rods to fully come all the way up and unlock the door?

Thanks,

AJ

Techno Duck · Techno Duck's Garage

AJ, its been a while since i took the door card off so i cant remember, but are the mounting holes in the door for the actuators slotted? Might just be a case of needing to tweak the mounting bracket a little to give them a bit more 'umph' in the unlock direction.

aj951 · 05-23-2011, 04:16 PM

Good suggetsion Techno, I didn't think to check the actuator mounting for adjustment. I only checked the door handle/lock mechanism. I will update once I go back in.

nize · nize's Garage

just a note: if the ignition is off, it will only lock and not unlock (anti-theft feature). i'm sure you all know that already.

wild man · 05-24-2011, 10:06 AM

Quote:

Originally Posted by nize

just a note: if the ignition is off, it will only lock and not unlock (anti-theft feature). i'm sure you all know that already.

I was going to mention that... But are you sure it's only with the ignition off? I was thinking that mine doesn't unlock via the inside rocker switch, even if the ignition is on. Is that the way it's supposed to be, or not?

aj951 · 05-24-2011, 04:37 PM

Update:

I removed the door panel and there is some adjustment available via the actuator mount. I adjusted it and it bought me very little travel. I observed the actuator motion while I had the panel off and it appears that when I push the central locking button on the console, the actuator only extends a little and stops. I can push the central locking button on the console 3 times with the actuator extending a little more each time until the door is unlocked on the 3rd push. Could this mean the driver for the actuators in the central locking unit is going bad? Both doors behave exactly the same which points to the central locking unit, I think. Has anyone else experienced this problem? Thanks for the help.

aj951 · 05-25-2011, 05:13 PM

Update 2:

I did some searching on the web and came across a thread on Rennlist where someone had the same problem I described above. It turned out that his Central Locking Module was the culprit and he replace with a used module and fixed the problem. I am attaching the link for refference. Anyone had this central locking problem? - Page 2 - Rennlist Discussion Forums

Today I removed my central locking module and removed the pc board to see if I could tell if there was any visable damage. I did notice a little spot that looked like it had been discolored near two resistors. I did some poking around with my digital volt meter and discovered that a trace between a 47uf capacitor and one of the resistors was open. I soldered a small mod wire to replace the broken trace and reinstalled the module in car without the cover. I operated to locks and everything is working perfectly now!

I have had the car for 4 years now and it has always had this problem so I don't know what caused the danage to the module. I don't know how long this mod wire fix will work but I will go with it for now. I will take some pictures of the board and the mod wire I added and post later so that it will be here for future reference.

A.J.

aj951 · 05-26-2011, 06:11 AM

Update 3:

As promised here are the photos of the central locking module board. The first photo is the front side view and I drew the broken trace with a green highlight.

The second photo is of the mod wire that was added on the back of the board to replace the broken trace identified on the first photo.

Anyway, I hope this information may help someone else in th future who experiences this problem.

nize · nize's Garage

that's a great find, where is the pc board located in relation to the car?

thanks for a great update!

nize · nize's Garage

Quote:

Originally Posted by wild man

I was going to mention that... But are you sure it's only with the ignition off? I was thinking that mine doesn't unlock via the inside rocker switch, even if the ignition is on. Is that the way it's supposed to be, or not?

when the ignition is on (or on acc mode), the power door lock button should both lock and unlock the doors.

if yours always only locks and never unlocks it sounds like yours is broken.

aj951 · 05-26-2011, 09:01 AM

Thanks Nize!

The PC board is inside a black plastic box (module) that is attached to the steering column with two metal bands underneath the drivers side dash. The whole module will remove from the steering column with a little bit of a tug. Once removed, you can disconnect the wiring harness connector and then the PC board assembly can be removed from the box. The PC board assembly slides out of the box once the little plastic ears on the box near the connector are flexed out of the way with a small screwdriver.

A.J.

Techno Duck · Techno Duck's Garage

Actually diagnosing and repairing an electrical fault?? Geez, usually i just keep replacing parts until the problem goes away..

.

aj951 · 05-26-2011, 11:22 AM

LOL! Techno

I do too normally. This is what happens when new parts are way too expensive, used parts are hard to find, and you have too much time on your hands

Plus I have gotten so much help from this forum, feels nice to give back.

A.J.

nize · nize's Garage

Quote:

Originally Posted by nize

when the ignition is on (or on acc mode), the power door lock button should both lock and unlock the doors.

if yours always only locks and never unlocks it sounds like yours is broken.

i just checked again.
correction:
the power door button both locks and unlocks only when the ignition is on. in acc mode and with key removed it will only lock and not unlock.

Memorex944 · Memorex944's Garage

Thank you guys for the suggestions. I do appreciate it a lot! Is there anyway to test the actuators, the locking mechanism without taking it to a dealer?

-Nick

aj951 · 05-29-2011, 08:13 AM

Memorex 944,

There is a way to test the actuators and locking mechanism. There is a description explaining the process in Volume 3 of the service/repair manual (page 57-15) if you have access to the manual. You have to provide a power source (either from the battery or seperate power supply) and individually actuate the actuators with the power source and jumper wires.

A.J.

Memorex944 · Memorex944's Garage

Thanks again, I really do appreciate it guys!

Nick

derekc23 · derekc23's Garage

My CLS has a red light lit up on it and nothing works except the key but the locks are out of synch on my '86.

But, with what I've learned here in this thread and over at RL I might have some ideas on what to check out first.