05 scion Tc, Utrastart 2256M Ready Mode

 Ok now I reread your # 3 a little closer, and think you are on the right track there, just make sure that you read and followed the instructions for the 556u exactly. It should of said if you needed the extra input for keysense. The 556u should bypass the immobilizer if programmed correctly. As far as I know, the immobilizer works by either cutting out the ignition or the fuel injection allowing the starter to turn over but not fire.or in your case stall out trying to go into res. mode. If  the 556u is programmed and installed right, when you pull your parking break, and tap your brake pedal with the car in neutral, you can turn your key to off pull it out, and the car will run for about 30 secs. for you to exit, then shut door. The car shuts off and is good to go.the car still thinks the the key is in the ignition. all of that is through the 556u with the key inserted right. to sum up all this redundant rambling, I think the second input is defeating the 556u, and the car doesnt see the key. Hope I'm helping, and not irratating you! keep us posted.jmacf14