You know, the 348 hvac module is known for many headaches. Try disconnecting/resettting battery/power to your car for 20 minutes. You'd be surprised at how many 'faults' can be cleaned up with a power reset. Hopefully you have a master kill switch in your car. Just kill the power for 20 mins, then start and let the engine warm up (5>8 mins) without touching anything, gas pedal, etc. In other words, let the computers relearn... like a computer reboot, only longer. When the cooling fans come on, you can shut it down, or take it for some exercise.... If it doesn't work, then your fault is legit!
Its the passenger sensor behind the screen at your knee. Just rap it a few times and it will clear. Seriously.