I know one such incident and I had shared that before. Pakistan had purchased few special trucks to operate in desert area during 2001-2002 Pak/India standoff and as always, they were delivered with certain conditions and restrictions not to open its sealed sections. One of the trucks got problems during its operations and it got stuck in desert. Considering war threats and expected delays in its fixing by American Engineers, our militry Engineers opened one of those sections and found it was carrying homing device. Pakistan returned those trucks back to our "friend" the expressed their anger for spying and deceiving us.
When I came to know about that accident, I had asked the forum members to share how reliable Americans equipment could be and senior members stayed silent while newbies like me responded but I wans't able to get anything conclusive out of discussion. America is a mean country and a friend worst then Enemies. Look at matters of drones and secret Black Water + hostile behavior of American Consulate staff here in Islamabad and rest of the country. I have every reason to suspect that the equipment that America gives to any country contains few elements such devices that America could use to its advantage, either by spying or by incapacitating its own supplied equipment.