Injector electrical codes 2012 D16

SPN 652 FMI 5
SPN 653 FMI 3
SPN 653 FMI 13

Truck started acting up and misfiring, then the electrical codes showed up an hour or so later. 2 injectors at the same time. We limped about 250 miles to dropoff, then ran it to the shop. The next morning the out of balance code showed up on the 3rd injector. The truck has been in the shop for 3 weeks, and they're stumped on how to diagnose and repair. They say Volvo recommends replacing injectors.

They've replaced the ECM and then the wiring harness, but they're saying it is still showing codes. I was under the impression that the harness cleared the first two codes, but left the out of balance code on the 3rd injector, although the last time I talked to them all 3 were still active. I'm still unclear about that. Is the next step to replace injectors, or at least the #3, or is there somewhere else we can look to potentially solve our issues?

I will try to get more clarification, but they're not very good at communicating with each other or us.

Thanks

 

Problem was 2 faulty injectors going out at the same time I guess. They said when they took the injectors out that they tested bad, but they tested ok while installed.