Conditions for Running the DTC

WARNING: This page is about a different car, the 2004 Buick Regal. However, it is still accessible from the selected car via links, so may be relevant.

The Ignition 1 Signal parameter is more than 11 volts.
The EGR command will be disabled if the start-up ECT is less than 5°C (41°F), and will not enable until the ECT is more than 75°C (167°F).
The EGR valve is commanded to open.
The EGR flow test is not running.