VR Keyhead progamming, but not in a VR...

[ev351]

Hi all,

Could some share the theory of operation of the VR low series BCM please?

I want to use a VR BCM as a central locking remote controller in another car.

Why?

I like the paddle pop key.

I like the interior light coming on at unlock

I have to much time.

Currently I have the BCM on the bench functioning with its original key.

I went to a locksmith and got the key copied and came home.

Locksmith told me to unlock the car with the old key and then put new key in the ignition and turn to ACC for 30 secs. Firstly is this procedure correct for a VR?

Heres my problem. I don't currently have the key reader connected, but from what I can see all it does is connect the key reader input and ground to the key????

If so, does anyone know weather the pin on the key is supposed to connect to the key reader pin 27 on BCM and the actual key connects to ground or is it the other way around?

Also, Looking at the BCM wiring, I see only +Bat continuous and IGN fuse connections. So if they are correct saying turn to accessories how does the BCM know when I go to accessories?

Any help would be appreciated.

Thanks everyone.

Ev.

[pman92]

The pin thing on the key head goes to the BCM (via the key reader usually, all the key reader is is an electrical connection between the key and BCM)
The key blade itself goes to ground

I've had keys copied myself and every time I get a different set of instructions. 'Leave it on accessories for a minute', 'leave it on ign on for a minute' etc. the only thing that's been common is to unlock with the original key first. Not sure what the point of these instructions is or if they are even required.

[ev351]

Ok thanks for the reply. I will give it another go. Im connecting the key head direct to the reader wire and ground. Im wondering what the conditions are for the BCM to believe that accessories are turned on.

Thanks. Ill keep plugging.

Ev.

[ev351]

Ok, So Ive been playing around a bit more. Bear in mind that this BCM is on the bench not in the car.

So, I need to know from start to finish what happens from when you push the unlock key on the remote to the time you turn on ignition. So its a 788 low series BCM.
We all know that when you push the remote and unlock the door, the interior light comes on. So far I have this happening.

Then, when you put the key in the ignition and turn to on, the light goes out. This is not happening. So my first problem is what happens to tell the BCM that the ignition is on? I thought from the diagram that it would be when the ignition is connected to pin 19. But my light stays on. It only turns off after the timer runs out. I think this is why I cannot program the new key as the BCM is not seeing the ignition come on, so it does not try to read the key..

does this make any sense.......??

Ev.

[j_ds_au]

When it reads a key, I think the BCM wants to tell the PCM about it. Maybe without this, the BCM behaves differently, doesn't know what it should do?

Joe.

[ev351]

Hi Joe thanks for that. It's an interesting point. I might plug it in to a working car and try again. I don't suppose anyone has measured the volts from the key reader ring to the centre of the barrel? Because when I measure the reader input line and ground I get zero. But when I go from the ring to positive I get 12 volts.....

[pman92]

I measured the reader voltage on a VT, probably the same.
It definitely had 12 volts on it.
It wasn't always on though, looked to be switching on and off (was too fast for a multimeter which is all I used)

[ev351]

Oh ok,

Maybe that is my problem. Might have to get out the crow.... Hmmm... Im still not meeting the conditions to program this damn key for some reason.