Why doesn't my trunk lock?

[Link]

Recently my trunk quit working, and not only that but other strange functions.

When I pop open my trunk it locks all my doors. Then when I shut the trunk the trunk remains unlocked, and doors stay lock. I can lock all my doors from the trunk, the trunk still does not lock though. I can not unlock my doors from the trunk. Only lock them.

Any ideas?

[Link]

Bump. Still no luck.

[ELVA164]

Hmm, maybe the latch in the trunk is sticky and gets far enough to send the "lock" signal to the doors but doesn't lock itself? Spraying with lithium grease would be a good idea for all the latches.

Wait, reread your post. The fact that the trunk never locks sounds like that latch has broken somehow. A stuck latch wouldn't allow you to turn the key and a broken actuator wouldn't keep the trunk from locking. I would try replacing it with a known good latch if you have one and go from there.

[Link]

Bump, still no luck.

[StereoInstaller1]

Alright, let me see if I can help here.

First, the lock actuator is also the thing that tells the central lock system to change. The sensor is built into the motor, meaning that the thing that moves is also the thing that tells the rest of the system to move...so if it is out of adjustment or otherwise improperly working, the whole system is messed up.

Make sense so far?

So, first thing to do is in your head, separate the central lock system from the key cylinder. This is really important, the two systems are separate, but operate together.

If your key cylinder is fuxxord, I have no help for you, sorry. I will help in electrical, but for the rest of it you are on your own.

The system has 2 parts: the brains and the actuators.

The little motor that runs the lock itself is called an actuator. If you look, you will see that the front doors and the trunk actuators have 5 wires. Rear doors and gas tanks only have 2. There is nothing in there but a tiny electric motor and a "rack and pinion" on the 2 wire actuators, very simple. For the "Master" actuators with 5 wires, the "other" 3 wires are to tell the central lock brain what to do. The brown wire is a simple ground and the central lock brain listens to whichever one is the odd man out, locking or unlocking as needed.

So, what this means is this: whenever diagnosing a locking system issue as weird as this, the first thing to do is get the electrical separated from the mechanical...meaning, unplug the thing and see how the lock itself is working.

Making some sense to you?

Luke

[Link]

Thank you, I was able to find a known good trunk actuator for cheap that I will replace to see if that helps the issue. But from what you are saying I am going to unplug the actuator and then see if the lock works on its own with no electrical, if it doesnt then the actuator isnt the only faulty part.

Reason to replace the actuator first: when I open my trunk my doors all lock.
Reason something else may be broken: no way to lock trunk currently.

Bump.

[StereoInstaller1]

Why immediately think "replace"?

[Link]

Impulse purchase? Who knows. I am in need of a locking trunk. Where do you suggest I start of not to "replace" parts?

Thanks!

[StereoInstaller1]

Diagnose first, then find parts.

Did you unplug that actuator yet?

[StereoInstaller1]

Update?

[Link]

I am waiting for the known working actuator to arrive before I mess with it more. I do not have a garage anymore to work in so it is more difficult. Will update in a weeks time.