how to interupt the RAP circuit?

[marin8703]

i need some help, and hopefully someone can help me out.

what i would like to do is to be able to somehow interupt the RAP circuit with a relay.

The reason for this is that i would like for the circuit to be off once the remote start on my truck goes off. The way it is rite now, is that if i remote start the truck all the accesories come on, and that all rite, but sometimes i need to abort the remote start (change my mind or something) and when I do that the RAP is still powered, and things such as my radio and some other add-ons are still going.

One thing i though of was to pulse the door switches (simulate an open) door, but that would sound off the alarm, unless i isolate it before that (dont really want to got this route).

So im hoping someone knows a trick of doing this.

Thanks for any help, it'll be greatly appreciated.

[navigator32v]

The best way I've found to interrupt some RAP is to turn on the ROCK! I'm sorry I had to say that...good luck though.

For those about to rock we salute you!

[H3 Alaska]

My son will know if this is even possible. I'll ask him, but he is in a car show this weekend so it may take a few days to get back at you.

[marin8703]

Appreciate the help H3Alaska. I can wait, if i dont get any ideas then i just wont be able to do anything so no rush.

navigator, Rock is a good RAP interupter but i donno how to worrk that into the circuit.

[f5fstop]

Technically, the RAP circuit on the H3 does NOT control the radio, it supplies power to components such as the sunroof, wipers, windows, and the power is supplied through separate fuses that obtain power from the RAP/ACCY relay. This relay is controlled via a ground wire by the BCM; which as you know, shuts down power about ten minutes after the ignition has been turned off, or a door has been opened or closed after the ignition has been turned off.
The Radio, as well as a few other components, is not part of the relay controlled RAP circuit. The radio is fed constant battery voltage that serves two purposes. One, keeps any memory settings that are not contained on a non-volatile memory chip, and is used to power the radio when the turn on signal is received from the BCM.
When you start the vehicle, the BCM sends a turn on signal to the radio via the class 2 serial data circuit, and the radio wakes up and goes to the last position you had set on the radio (on/off, CD/radio, etc.). After you turn off the ignition, the BCM will shut down this circuit at the same time it removes the ground to the RAP relay.

That's how the two circuits operate. Is there a way to override the RAP circuit? I would say yes, but it would depend on obtaining a signal from the module used to remote start the vehicle, and I am not familiar with that item. As for the radio circuit, that would require interfering with the serial data circuit, which, unless you know exactly what you are doing, I would not touch. Consider this to be the internal local area network where all the computers talk to each other. (This is the circuit where the BCM sends the security ok to the PCM, this is the circuit that verifies VIN numbers of components, etc.)

[marin8703]

Originally Posted by f5fstop

Technically, the RAP circuit on the H3 does NOT control the radio, it supplies power to components such as the sunroof, wipers, windows, and the power is supplied through separate fuses that obtain power from the RAP/ACCY relay. This relay is controlled via a ground wire by the BCM; which as you know, shuts down power about ten minutes after the ignition has been turned off, or a door has been opened or closed after the ignition has been turned off.
The Radio, as well as a few other components, is not part of the relay controlled RAP circuit. The radio is fed constant battery voltage that serves two purposes. One, keeps any memory settings that are not contained on a non-volatile memory chip, and is used to power the radio when the turn on signal is received from the BCM.
When you start the vehicle, the BCM sends a turn on signal to the radio via the class 2 serial data circuit, and the radio wakes up and goes to the last position you had set on the radio (on/off, CD/radio, etc.). After you turn off the ignition, the BCM will shut down this circuit at the same time it removes the ground to the RAP relay.

That's how the two circuits operate. Is there a way to override the RAP circuit? I would say yes, but it would depend on obtaining a signal from the module used to remote start the vehicle, and I am not familiar with that item. As for the radio circuit, that would require interfering with the serial data circuit, which, unless you know exactly what you are doing, I would not touch. Consider this to be the internal local area network where all the computers talk to each other. (This is the circuit where the BCM sends the security ok to the PCM, this is the circuit that verifies VIN numbers of components, etc.)

I probably should have said this in the beginig, but i have an aftermarket pioneer avic-z1 installed. As far as i could figure out its workings this is how its power operates. It has fulltime power via a constant yellow and it has accesory or ignition power via red, and the unit looks at that red to know when to turn on and off. The control of the red is on a relay that came with the wiring harness of the unit itself. It gets the power from the yellow, and relays it to red when ever ignition is on, and it seems to monitor, not use, but just monitor the RAP circuit, as far as I can tell. That relay is controled by some wire coming out of the Peripheral onstar adapter, but i didnt just wana start poking at things without knowing what they are, and it is very hard to get to, so if another route is possibble it would be better. The Z1 unit operates the same as windows and sunroof and all that. But I think it doesnt use their power it just looks to see if it should be on, because of that relay thats on its own wiring harness. Im not 100% sure about the last sentence.

As usual I do things without really planing them out, so last weekend, i thought i had the solution, put a relay (breaks red while on) on the ignition/accy controlled red that is at the z1's own relay, and control that relay with a status output from the alarm. Well, it worked, but not exactly rite. It keeps the radio off, but once the remote start is turned off (and thereby the relay connects the red again) the radio comes right on. And this is where I am now.

and the power is supplied through separate fuses that obtain power from the RAP/ACCY relay. This relay is controlled via a ground wire by the BCM;

Is there a way to override the RAP circuit? I would say yes, but it would depend on obtaining a signal from the module used to remote start the vehicle,

These two statements give me hope . The alarm I have has two remote start status outputs in the form of steady (-) 200mA. There is a flow while the remote start is on and stops are the remote turns off.

I was thinking maybe a pac-tr7 or someting similar and a relay can be probramed to flash this ground wire from the bcm that controlls the RAP/ACCY relay. Would that possibly work? Or give me whatever ideas you got. But that wont set off the alrm wite, it has nothing to do with the door swithces?

Thanks for the help, this will be a huge relife if it can get done.