I have a 2002 honda civic coupe ex 5spd. The other day while accelerating off a turnaround on the highway I lost power. The malfunction indicator light came on, the revs dropped to 0, and the car began running very rough and idling erratically. I got it towed to a shop where this morning they told me none of the computers could read the codes, and that the PCM was not working correctly. Any advice?

Try to read codes yourself. If you feel the PCM has failed, it's easy to install a remanufactured one for 1/3 the cost of a new one from Honda. Shop warranty and price. This link may help:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-selected-other-vehicles-46563-3.html#post235038

If you have an immobilizer system, which is likely, you may need to get your current PCM remanufactured.