Anti-theft key issues

[Ludachris]

So the door handle was replaced on my 2g before I bought the car at some point. I have the key for it, but the problem is this - if I lock the door before getting out of the car and try to unlock it with the key on the driver side and open the door the alarm goes off. I can close the door and turn the key to re-lock it and it turns off the alarm. And then when I turn the key yet again to unlock it, it will disarm when I open the door. ?

I also noticed that the passenger door lock has a broken piece of plastic inside the door that prevents the auto door locks from working. If you lock the door from the passenger side, it locks that door only and doesn't arm the system. Yet, it will disarm if you unlock it with the key on the passenger side. I located the white plastic lever inside the door that is missing, as I can see it on the driver side.

I just want to be able to unlock and disarm the system with the key on the driver side. Seriously, it shouldn't be this difficult. If it arms when I lock it from the inside shouldn't it disarm when unlocking from the outside using the key?

 

[stars]

Sounds complicated but, I will give this a try. Is this a factory alarm or aftermarket? What is needed to figure this out is what components they used to trigger the alarm.

Now, since both doors should lock from the drivers side and from the passengers side, I'd suspect a faulty door lock mechanism(s) or could be a broken/shorted wire from the unlock side not sending signal to the alarm itself. But, do not go out and replace those just yet as it may just be a mix up in the wiring or perhaps that broken piece you found is the key to solving the problem that easily. If it arms/disarms the alarm from the outside then we know that that part is functioning properly. Now, what sounds like is happening is that the alarm is not receiving the command to arm/disarm itself if when locked from the inside manually not using the key? Since both doors should lock and unlock both simultaneously your task is to figure out what wires are going to the alarm from the door lock mechanism(s). It is getting signal from the outside when you use the key but, with one or more door locks not being registered by the alarm, it will think that there is unauthorized entry. I'd suspect the wiring in the door lock first because both doors should automatically lock and unlock both from the inside and outside. Both door locks are wired in pairs but since they are operating separately, it is like you have 2 separate problems that the alarm cannot distinguish.

Sounds complicated but work through it, if it is in the wiring then a schematic will be needed. With one lock operating properly and the other one not so properly then I'd look at that problem first until fixed. Then I'd suspect the wiring or faulty locking mechanisms. Give that a try and post back, and we will go from there!

 

[Zack Huffman]

Chris, is yours keyless entry equipped? If so, I think your problem may be a break in the green with white stripe wire that connects between the driver's side door key cylinder switch and pin 38 of the ETACS ECU. Pin 38 should be grounded by the switch when the cylinder is turned to make contact in the unlock direction of the switch. Test to see whether the voltage at pin 38 of the ETACS ECU goes from 5V to 0V when you turn the door cylinder to unlock.

 

[Ludachris]

Thanks Zack and stars. The car has a factory alarm (the green Security light goes on when I lock it before I get out), but I found evidence that it had an aftermarket alarm at some point to when I was tearing out the old stereo a while back, so who knows what was hacked. The wiring in the doors looked fine. I'll do some more searching under the dash.

 

[Zack Huffman]

Well, either way, your problem lies in the aftermarket alarm brain (or ETACS ECU) not recognizing the door's lock cylinder switch being turned to the ground contact it should hit when your key turns the cylinder to the unlock position.

You obviously have the lock side of the switch functioning correctly, since you are able to deactivate the alarm by re-locking and then unlock the door again before the system re-arms itself (when the green dash light goes out, the system becomes armed).

Either the cylinder switch, the door lock, the alarm brain (or ETACS ECU for the factory system), or the wiring from the cylinder switch is at fault. The alarm is going off because it's controller (or the ETACS ECU) doesn't receive a ground from the switch when the lock turns in the unlock direction. Same reason that, when the system fully arms, opening a locked door from the inside handle by reaching through an open window sets off the alarm.

The ETACS ECU is located on the back side of the interior fuse box. The plug on the side by the driver's door is the one that you need to probe. That connector houses ETACS pins 21-40.

 

[Ludachris]

So check this out... pulled my driver seat to test fit the Cipher seats I'll be putting in and just happened to see the wiring loom at the door sill. Found a red wire with green strip that was cut and tapped into, sitting there with bare ends. Luckily it didn't start a fire! I connected the wire and taped it up and it seems to have fixed the door lock issue with the key on the driver side. Just one of the things you deal with when buying a car that's been hacked.

 

[Ludachris]

Strangely enough, I just tried unlocking the car at the store and the alarm went off. I don't understand how this is so intermittent.

 

[stars]

They must have another wire tied into the alarm system that sets the trigger. Could be interior lights, but chances are you may have found just one of the problems under the seat. It certainly sounds like you have another wire that is causing this problem. I would take out the interior carpet and check the harness all the way back to the dash where the alarm is installed. If that doesn't look rigged then start checking continuity on the alarm wiring. Since they had 2 different alarms installed, I'd say they defiantly jerry rigged the system when they installed it. I figured you had atleast 2 problems so, you got one solved. I know how electrical problems can be, a real pain in the sphincter if not done correctly. Keep searching you will find it!