Conditions for Running the DTC

WARNING: This page is about a different car, the 2004 Pontiac Grand Prix. 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 start-up engine coolant temperature (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.