non-ignition-controlled door lock

Hello.

I am having an Audiovox APS996A installed in my 2005 Honda CR-V SE, automatic tansmission. I found out that the alarm has ignition controlled lock/unlock but I desire something else. I would like the doors to lock under one of the following (in order of preference)

• when the car reaches a certain, minimum speed
• when the car is put into a driving gear (non-park/neutral)
• when the seat belt is fastened

For unlock, triggering from ignition off will suffice.

Although, I am not an installer, I have a technical background which includes in electronics (555 timers, Op amps, diodes, Ohm's law, etc.) so I'm thinking I can come up with something with/for the installer. Forgive my lack of proper installer jargon.

I have been Googling around for a week and I found a 2004 Honda CR-V wiring diagram at http://www.bulldogsecurity.com . I understand the 2004 wiring is the same as 2005. I read up on ignition controlled door locking. I still need some info to fill in some knowledge gaps.

My theory is this -

1) To make the doors lock when the vehicle reaches a certain speed, I have to trigger from the vehicle speed sensor (VSS). I understand that the VSS has a voltage range, corresponding to vehicle speed, and I can trigger from a point in that range. The problem is the wiring diagram I found doesn't have it listed. Also, I don't know how to test the voltage while driving the car. I don't have a access to a dyno. I might persuade my mechanic (who is not the installer) to use his.

2) To make the doors lock from the gear shift I need a gear trigger. I assume there must be one because the car has functionality that requires knowledge of whether its in a driving gear or not. The problem is the wiring diagram I found doesn't have it listed. Does it exist?

3) Triggering from the seat belt is the same problem as #2.

I figure once I find the trigger, then the door lock relay, input diode isolation and latch to pulse conversion is standard. I can figure out how to convert the VSS voltage into a trigger, if I can find the VSS wire.

I went to the service department in my dealership and they are less than informative. Any help is appreciated. Thanks in advance.

-TekNut

ok my idea would be to use option 2 (the gear shift one). Find your reverse lights wire (usually listed on any tech sheet). This will provide your trigger. In order to make sure the doorlocks do not stay energized when you are backing up what you will need is a capacitor and a relay. Hook up the reverse wire to the positive trigger wire and ground the negative trigger wire (pins 85 and 86). Hook pin 87a to your unlock wire, pin 87 to ground, and pin 30 to the negative size of your capacitor. The other side of the cap should be hooked to ignition. What this will do is when you shift into reverse it will "click" the relay and charge the cap. As soon and you go out of reverse the relay will "unclick" and the charge that was just stored on the cap will be discharged into your unlock wire. The only two small problems I can see with this is that the locks will not lock until you stop backing up (not many of us drive around backwards so it shouldnt be too much of an issue) and when you put the car back in park the locks will lock again but seeing as how you have ignition controlled unlock the doors will unlock anyways when you shut the car off.

Anyways just saw the thread and thought of something really quick, I'll keep thinking but if anyone has something better post it so we can all see it.

Hope this helps buddy,

Thanks guys. I spoke to my installer about the VSS technique and he said I could have problems with the Honda warranty and/or screwing up the ECM. So I'm going with the gear change idea as it seems safer.

Fbird, you rock! Great idea! That never occurred to me. But how about triggering off the PRND lights on the dash? I charge a cap  in P and discharge in D. I hold the discharge voltage with an RC timing circuit and drive the door lock  with it. This way it only works going from P to D and not the other way. No redundant lock triggers. I know I'll need some relays and maybe a diode or two but my installer should be able to figure out the details.

My installer says the Viper 791xv has programmable door lock/unlock (and he hates Audiovox customer service, anyway, and frankly, they haven't been too helpful with me either) so I'm going with that alarm and I'll disable the alarm's door lock and use the aforementioned circuit. Seems pretty simple after all.

Thats my plan. Thanks again.

-TekNut