Hi,
Car dealer is telling myself, when my seatbelt went bad, it must have fried the CPU and now the CPU needs to be replaced on my 1990 Honda Accord. This seems odd to myself. Is the CPU another acronym for the PCU/ECU/ECM? I am unable to find this part listed on either HONDA's own web site, in my Haynes repair manual, on the web in various glossaries, and/or in my owner's manual. Please help. Thank You!

I'm not sure what the relationship is between the seat belt and the ECM (CPU, computer, PCU). Read sections A and B below and run your own diagnostics:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-46563.html

Be sure to perform the simple K-Test on your ECM. If you need a new ECM, consider replacing it with a Cardone remanufactured ECM from O'Reilly Auto Parts. It will cost 30% of what Honda wants for one with a 1-year warranty and you'll get a lifetime warranty, instead. Here's what your ECM looks like and costs:

Zip Code Entry at PartsAmerica.com (http://www.partsamerica.com/ProductList.aspx?PartType=248&PTSet=A&SearchFor=Engine+Computer)