Just purchased my first Tahoe, 2005 Z71. Everything was working perfectly until I installed a flashing blue LED fake security light in the dashboard. I tapped the two wires for the LED into the fuse box on the side of the dashboard. The LED was working fine, but now either coincidentally or as a result of what I did the check engine light is on and the transmission is in limp in. PO codes 758 740 753 785 2761 are coming up. I did check all the fuses I could find and everything seems good. Could this be something I did in the fuse box or is it just something like a bad ignition switch?