B1400 No cold AC on 2004 Prius

Thought I share symptoms (and solution) so the next person who encounters this problem can save some time. Customer bought a used 04 Prius, no cold air. No AC error codes other than B1421 (which all Prius have when scanned indoors) and B1400 which I'd never seen before.

I then noticed the MFD doing funky stuff. At random times the ambient temp display would show 23C instead of 73F.

No matter what temp I selected, after car restart the temp setpoint would be 75F
(normally the car remembers your last temp preference)

I evacuated refrigerant and installed correct amount. No cold air.

I decided to change the AC Amplifier (ACU ECU) which is located "above the hump" (actually just above of airbag computer that has yellow connectors).

Anyway, a replacement AC Amplifier solved the MFD problems and restored COLD AIR!