Diagnostic Overview
CAT fault code SPN41216 is best normalized as SPN 412 FMI 16. SPN 412 is commonly associated with EGR temperature or EGR-related temperature feedback. FMI 16 means the value is above normal at a moderate severity level. In practical terms, the ECM is seeing EGR temperature higher than expected or receiving a signal that makes it appear high. This can affect EGR control, engine protection, and soot production.
Likely Causes
Restricted EGR cooler; reduced coolant flow; failed EGR temperature sensor; wiring issue; high exhaust temperature; stuck EGR valve; cooling system issue.
What To Check First
Compare EGR temperature data to actual conditions, inspect EGR cooler and coolant flow, check the temperature sensor circuit, and look for related overheating or exhaust temperature codes.