I am having the same experience, and posted in the wrong place. Pretty wiped out from the troubleshoot. I find that if I ground the small center wire under the battery, on the big relay for the air pump, near the air pump, the pump will operate. I went so far as to check continuity from the pump relay center wire all the way back to the Engine Control Module (ECM), pin number B38. No troubles there. I am wondering if it is a computer problem, or if the ECM computer is looking at more than just the coolant temperature.