Here is a list of the stock receiver connector pins for 2009 regular and double cab models.
I believe you want the one called Illumination (rheostat) signal. Which connector that is depends on if you have the system with a built-in amplifier or not. If you have the system with a separate/external amplifier then the wire you want is on connector K4 at position 12. If your system has the built-in amplifier the wire you want is on connector K2 at position 5.
DISCLAIMER: If this is not correct, don't blame me. I pulled this from the Toyota repair manual, lol.
EDIT: Holy #@&% I didn't notice the attachment was 1.5Mb. I just uploaded a much smaller one.
2009 Crew Max 4x4
6" Pro Comp lift
20x9 +18mm Fuel Hostage wheels
35x12.5 R20 Toyo Open Country M/T tires
Black Headlight Mod
35w 5000k HID Lows
Autobot Grill Emblem
ArmorLid Tonneau Cover
BEDRUG Carpet Kit
SteelCraft Side Rails
WDTV Live Plus Media Player
Boyo License Plate Back-up Camera
Pioneer AVH-P4300DVD Receiver, 4 Infinity Kappa63.9i 3-way 6.5" speakers, 2 JL Audio 6W3 subs, 2 JL Audio 10W1 subs, Infinity Kappa 4 & 5 amps
Last edited by Bigwheel; 03-25-2011 at 08:19 PM.