Diagnostic Overview
MaxxForce fault code 345 is listed as a turbo-related entry in the supplied list, but it is incomplete without SPN/FMI or diagnostic description. It should be used as a pointer toward air-handling or turbocharger control. Symptoms may include low boost, high boost, smoke, poor throttle response, or derate depending on the underlying failure.
Likely Causes
Boost pressure sensor issue, turbo actuator fault, charge-air leak, exhaust leak, intake restriction, wiring issue, or turbo mechanical wear.
What To Check First
Confirm the full diagnostic definition, inspect intake and exhaust plumbing, compare boost sensor data to expected values, test turbo actuator response, and check for companion EGR or derate codes.