That is top secret. Only the people at GM who wrote the service manual know that, and they do not want anyone else to know, as evidenced by searching for half an hour with no answer. I can tell you it feeds the engine computer, mass air flow sensor, ... Well, it is faster to look at the diagram.
My guess would be "engine control system" or "emissions control system".
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Tuesday, January 30th, 2018 AT 6:03 PM