vin: 1GCCS145028196593

This morning My Mother in Law asked me to check out her truck... i hooked my computer tester to it and i got all these codes.
C0221 C0222 C0225 CO226 C0227 P0303 P0440 and this one really makes me wonder: P1621

I know what each one is for, but surely all these could not of went bad? so I am wondering if the Control Module which I guess is THE PCM or ECM if that main computer went bad if it would make it look like all these other things were bad? Its not my truck so I hate guessing and changing parts when it might not be the parts that are bad. but the main computer because of the P1621 code....sure would like some thoughts on this..... Thanks