I've a 2010 Q5 with the 3.2 and the CEL has been coming on - VAGCOM indicates P0491 and P0492 - insufficient air flow secondary banks. Have started to check the system and my first point is the pump. I've disconnected it and fed it directly with 12 V and it just buzzes with no air. I've tested it using a DC power supply rated at 6 amps max and am just wondering if its enough power as the air injection system fuse is 40amp. I can touch the top of the impellor inside the pump and can rotate it slowly - feels really stiff. My question is, is the pump toast or am I just testing it with an insufficient power source to get it to rotate and any recommendations as to where to source the pump? it's looking like an expensive part (in Canada), thanks!