So I had an F2 and F3 sensor fail. I swapped cpu's in my vehicles and updated all firmware. Then I was only getting automatic senor check fail senor F2. The other vehicle runs fine. I had been debating on updating to a TX head for the front. (quint systems on both vehicles) so I used this as the opportunity to make the swap. I first tried plugging the TX head into the existing extension line to the cpu. getting same error code. so I run the new extension wire from the TX head to the CPU and getting the same error still. Any ideas on what to check next?