Retained Accessory Power (RAP)

DAVe3283

Heavy & Slow
Sep 3, 2009
3,727
296
83
Boise, ID, USA
I wanted to get a high-amp Retained Accessory Power (RAP) source in the least ghetto method possible. I searched around online, and couldn't find a good guide, but I eventually figured out this method.

This replicates how GM supplies RAP to the sunroof. If you have a sunroof already, you will be able to splice in to the factory relay output and be done! See the attached schematic.

First, ensure your vehicle has the Sunroof fuse in the underhood fuse block!
Sunroof Fuse.jpg
Both my 2003's have it, despite not having a sunroof.

Tools & Parts Needed

  • Connector: 12193929 (OEM part, green color) or 12193930 (black equivalent)
    • If you have roof marker lights, you should already have this connector and can just add pins to it!
    • These are hard to find, but I have a bag of the black ones. If you need one, PM me. Or raid a junkyard, all the colors should interchange.
  • Terminals: 12129424 (3 needed)
    • Mouser electronics and Amazon carry these
  • Terminal crimper (or go nuts with some pliers)
  • Universal relay & relay socket
    • You can also use a GM relay & socket out of a junkyard
Locating the Connector
The connector we need is C6 in the Right IP Fuse Block.
Fuse Block Right IP Location.jpg

Pinouts
Fuse Block Right IP Top View.gifC6.gif
View attachment Fuse Block Right IP C6 Pinout.pdf

We only care about pins A, C, & D.

  • Pin A to relay pin 30
    • This is battery power from the sunroof fuse
  • Pin C* to relay pin 86
    • This is a ground for the relay
  • Pin D to relay pin 85
    • This is the RAP trigger from the body computer to the relay coil
*Pin C will have a wire in it already if you have roof marker lights. If so, remove that pin from the connector, and cut off the existing connector, & crimp that wire into the relay ground too. You can see where I did this in the photos below.
*If you need a ground for your accessories, you can add another ground wire here too, though it gets harder to crimp with more wires. I just grounded my toys elsewhere.

Fuse Block Right IP C6.jpgRelay & socket.jpg

Install the new relay
Right A-Pillar-Middle(c).gif
I installed the relay in the factory location (#2 in the diagram above). It gets taped to the roof marker harness (if you have one) and simply tucked up along the A-pillar beside the glove box.

You can now attach your accessories to pin 87 on the relay, and they will turn on/off with the RAP circuit! You might consider changing the Sunroof fuse from 25A to something smaller that matches your needs better.
 

Attachments

  • Power Sunroof Schematic.jpg
    Power Sunroof Schematic.jpg
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  • Fuse Block Right IP C6.jpg
    Fuse Block Right IP C6.jpg
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  • Fuse Block Right IP Location.jpg
    Fuse Block Right IP Location.jpg
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  • Fuse Block Right IP Top View.gif
    Fuse Block Right IP Top View.gif
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  • C6.gif
    C6.gif
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  • Fuse Block Right IP C6 Pinout.pdf
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  • Right A-Pillar-Middle(c).gif
    Right A-Pillar-Middle(c).gif
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  • Relay & socket.jpg
    Relay & socket.jpg
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  • Sunroof Fuse.jpg
    Sunroof Fuse.jpg
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Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
21,667
5,813
113
Phoenix Az
Dave, you have any idea how to fix the corrupt coding for RAP on the 01-02 trucks when you flash a DSP OS in? I’ve been on single tunes since 2012 and it would be nice to have that back consistently, not when it feels like working.
 

gmduramax

Shits broke
Jun 12, 2008
4,072
248
63
Nor cal
Dave, you have any idea how to fix the corrupt coding for RAP on the 01-02 trucks when you flash a DSP OS in? I’ve been on single tunes since 2012 and it would be nice to have that back consistently, not when it feels like working.

DSP’s are for girls ;)
 

DAVe3283

Heavy & Slow
Sep 3, 2009
3,727
296
83
Boise, ID, USA
Dave, you have any idea how to fix the corrupt coding for RAP on the 01-02 trucks when you flash a DSP OS in? I’ve been on single tunes since 2012 and it would be nice to have that back consistently, not when it feels like working.
I'll have to troll through Techline tomorrow and see what I can find. On the 2003+ you'd just reflash the BCM with the stock program again to fix any corruption, but I'll see if anything different jumps out at me for the 2001-2002.
DSP’s are for girls ;)
Yeah, I still have a DSP switch wired in to my truck, but switched back to a single OS when I built the motor. Why not tow on a 660 HP tune? :D I think James agrees with me there too, only more so.

Sent from my Cat S60 using Tapatalk
 

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
21,667
5,813
113
Phoenix Az
DSP’s are for girls ;)

:roflmao:

I'll have to troll through Techline tomorrow and see what I can find. On the 2003+ you'd just reflash the BCM with the stock program again to fix any corruption, but I'll see if anything different jumps out at me for the 2001-2002.Yeah, I still have a DSP switch wired in to my truck, but switched back to a single OS when I built the motor. Why not tow on a 660 HP tune? :D I think James agrees with me there too, only more so.

Sent from my Cat S60 using Tapatalk

couldnt agree more Dave :D:D
 

DAVe3283

Heavy & Slow
Sep 3, 2009
3,727
296
83
Boise, ID, USA
The 2001-2002 uses external relays instead of data bus messages for most of the RAP features, but it is all still controlled by the BCM. I attached the diagnostics I found.

Really, it looks like the best bet is verify the door switches are all working, the ignition switch isn't flaky, and then reflash the BCM with the stock calibration and see what happens. That's what I'd do. You can also command the RAP relay on if you happen to catch it when it isn't working, and that will tell you if it is a programming glitch or hardware problem.
 

Attachments

  • 1 Retained Accessory Power (RAP) Description and Operation.pdf
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  • 4 02 GMT800 Rap 2 Relay, G200, Sunroof Module, Window-Door Lock Switch.jpg
    4 02 GMT800 Rap 2 Relay, G200, Sunroof Module, Window-Door Lock Switch.jpg
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  • 3 02 GMT800 Rap Relay, Radio, Window-Door Lock Switch.jpg
    3 02 GMT800 Rap Relay, Radio, Window-Door Lock Switch.jpg
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  • 2 RAP Schematics - Pickup.jpg
    2 RAP Schematics - Pickup.jpg
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  • 5 Diagnostic System Check - Retained Accessory Power.pdf
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  • DTC B1477.pdf
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  • DTC B1478.pdf
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  • 6 Symptoms - Retained Accessory Power.pdf
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  • 7 RAP On After Timeout.pdf
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Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
21,667
5,813
113
Phoenix Az
You the man dave. I’ll play with it. The RAP either works or doesn’t. When it doesn’t, the radio and everything shuts off soon as you kill the ignition and never have touched the doors. Started right after I did the dsp flash. Ferm was saying when you flash the dsp os in, it corrupts some part of the bcm and makes it sporadic.