Exhaust Gas Recirculation (EGR) Cooler System Monitor

EXHAUST GAS RECIRCULATION (EGR) COOLER SYSTEM MONITOR

The EGR cooler is monitored to determine if the EGR cooler efficiency is low. The EGR cooler monitor uses an exhaust gas recirculation temperature (EGRT) sensor and an EGRT2 sensor to measure the EGR cooler input and output and determine whether or not the EGR gases are being cooled effectively by the EGR cooler. If the temperature indicated by the EGRT2 sensor is above the maximum limit for greater than a specific amount of time, diagnostic trouble code (DTC) P2457 is set. The EGRT and EGRT2 sensors are monitored for circuit high, circuit low, intermittent concerns and rationality.