Try swapping the gateway board on the bad one to a different car to see what happens,and the shaft setup the car needs to be just a fuzz above the bottom 161 with 61u and 77n 30 on.i had a couple that were tricky,had to pull xm16 put it back in then flip to auto try bypassing doors,I highly suspect gateway and fcb.i put in many of these units and everyone was a learning experience