Guys, I bought a used 2006 ZX for my wife as an upgrade from her Blackbird, it had a PCIII on it and Yoshi slip ons, well I had Nels at 2wheeldynoworks flash my ecu and tune my 2012 at his shop and have always been beyond delighted.

So I pulled the ECU and sent it to Nels and removed the ground wire and unplugged the PCIII, put it all together and when ECU returned I installed it and fired her up but now it has the red light on the dash and the code, Nels said it may have a TRE on it, but I see on here that IF it has a TRE the gps won't work at all and prior to this the gps and dash indicator worked fine.
I DID install a secondary fan and switch and when the ECU was out I tested the remote fan switch a couple times, would turning on the key with no ecu cause an issue?
I started it and carefully ran it up and down to 3rd gear on the center stand and it stays on and shows 6th gear in between flashes of FI code being displayed.
Any thoughts?
Thanks