Possible Causes

WARNING: This page is about a different car, the 2002 Nissan Sentra. However, it is still accessible from the selected car via links, so may be relevant.

Malfunction is detected when no EGR flow is detected by EGR temperature sensor under condition that calls for EGR. Possible causes are:

Harness or connectors (EGR-VCV circuit open or shorted).
EGR-VCV stuck closed.
Dead (weak) battery.
EGR passage clogged.
EGR temperature sensor or circuit.
Exhaust gas leaks.