Hope everyone is having an awesome day

We had a customer come in with a 2004 Mazda RX8 with a dtc 0610. Customer has been previously to Mazda dealership a few times, had computer reflashed, engine has been changed @ Mazda. This code continues to come up. Could this be a possible PCM issue? (this is the customers first visit to us)
any thought or suggestion are greatly appreciated. Thank you