So far i have check the following: 1.-check the relay it self by manually appling voltage and they work. 2.- confirm that the grownd side of the relay coil is not open 3.- At the connector comming from the ECM there is no voltage when set the ignition switch on Am I looking into a defective ecm?

Another missing step... 4. What is the reported IAT temperature from the ECM? If the IAT sensor is bad and reporting unnormally high temperature then the grid heater are cancelled completely. I've seen one other report where a owner was seeing with a live data tool the IAT temp was 120*F on a -20*F morning... Of course the ECM takes this value and processes accordingly and not use the grid heaters. Like on my truck with the MPG fooler on my IAT is set permanently at 140*F and my grid heater are disabled...

Michael.. You were right, I confirm the proper operation this morning and the relay work ok, one thing i found was one of the coil relay conectors (comming from ecm) was loose so i crimp it with a pair of pliers and make the it fit in tight and problems was solve (i guess the p code was cause by a miss contact on this conector.