lexstratus

How do you get fault code on a CL700 Mack with Cummings ISX engine?"

Hey, I am working on a dump truck that belongs to my dad. I wondered if there was a diagnostic tool that would give me the codes. I don't want to reprogram anything just something to give me codes. We did an engine swap and it did good for last 3 months. It runs and hauls great for an hour then lightning bolt light comes on and you cant get over 1200 rpm. He thought it might be fuel issue but we have changed everything. I just need to get the fault code to isolate where the problem is located..