Since I'm not sitting in front of a manual. I tried to help you figure out how to look it up.
NU3 = crappy California emissions secondary air pump bs on your car.
Meaning, if there's a question that comes up from AllData, you want to select NU3 based cars. In the GM FSM it specifically asked. If you don't select it... no relay info, no pump info..no anything else info relating to it.
Beyond that attemp at help, I'd be stating the obvious "in the relay center". And we all know that's not what you are looking to hear. Surely you checked there already.![]()