00 malibu ls 3.1 p0403 Exhaust Gas Recirculation Circuit Malfunction,help

i have this 2000 chevy malibu ls 3.1
and i got the obd code - p0403 Exhaust Gas Recirculation Circuit Malfunction,,

i have tryed few tricks,,but did not worked,

,i have cleaned the egr,,checked the wires harness,,everything looks ok,,

i took negative wire out for 3,4 hours ,,and still the light is back on again,,

maybe i the egr is not clicking,,opening?

i have a diagnostic tool,,but did not see that future in to turn on/off egr,,

any ideas,,thanks