Derf, the schematic definitely helps. From what I gather the 2007 diagrams are virtually identical to the 2009 so thanks for that. I'm familiar with the BCM and it's "resistance" layout but all I really care about is what pin from the BCM controls a lock function. As for the trunk function, I should be able to make an educated guess by testing each BCM pin until the lock pops. I was able to install an aftermarket lock remote on my other boy's 2005 Malibu by tapping into it's BCM but needed a schematic to do it. With the diagram u sent I won't be flying blind so thank you. The boy now says he can't leave the car with me till Monday. If you are interested, I'll let you know how successful I am then but nothing's easy with the wiring in these new but now old cars. Thanks again

 

I will keep looking. Most definitely keep us informed and please post solution