Diagnostic Aids

WARNING: This page is about a different car, the 2019 Chevrolet Malibu. However, it is still accessible from the selected car via links, so may be relevant.

If the engine has cooled overnight, all exhaust gas temperature sensors and the engine coolant temperature sensor values should display within 3°C (5°F).
After starting a cold engine, the exhaust gas temperature sensors temperature should rise steadily, then stabilize after the engine reaches operating temperature.
High resistance in either circuit of an exhaust gas temperature sensor could set a DTC.
After a code clear, with an existing fault, the EGR temperature sensors briefly display the Typical Scan Tool Data chart fault values to indicate a fault type, then default to 200°C (392°F) after a few seconds.
With a fault present, the sensor reads a software defaulted value of 200°C (392°F) and does not change with an expected temperature increase or decrease.