EGT

📖 YOUCANIC Automotive Glossary

The EGT (Exhaust Gas Temperature) sensor measures the temperature of exhaust gases at various points in the exhaust system, providing critical data for turbocharger protection, aftertreatment system management (DPF regeneration and SCR operation), and emissions compliance monitoring. Modern diesel vehicles typically have 3-4 EGT sensors: before the turbo (monitoring turbo inlet temperature for protection), after the turbo/before the DPF (monitoring DPF inlet temperature for regeneration), after the DPF/before the SCR (monitoring SCR catalyst temperature for DEF dosing strategy), and after the SCR (monitoring overall aftertreatment temperature). Gasoline turbocharged vehicles may have 1-2 EGT sensors for turbo protection and fuel enrichment strategy.

EGT sensor failures affect multiple system functions. A faulty sensor before the DPF can prevent regeneration (ECU does not believe temperature is high enough to initiate) or allow regen at incorrect temperatures. A faulty sensor at the SCR can cause incorrect DEF dosing. DTCs include P0544-P0549 (EGT sensor circuit codes for various positions). The YOUCANIC UCAN-II displays all EGT sensor readings simultaneously, which is essential for monitoring DPF regeneration in real time and verifying aftertreatment system temperature management.