I connected the fail safe signal (reading at 1.3v as the tank is empty and triggers the fail safe)to the TPS sensor signal wire at idle and the car started to rev to 2500 rpms by itself. If I stepped on the brakes nothing happened. When I step on the accelerator it stays at the highest rpms that I went too. It resets after I restart the car no engine codes. So that did not work.

Please help me to understand grounding the ignition coil ground wires. So if they all receive a ground signal at the same time this tells the Ecu that something is wrong and goes into limp mode? Just to clarify, at normal operation they pulse their ground signals independently? Is this how it works?
Thanks