I've got an '07 Avalanche C4 and on the dashboard I have a light that says WARNING, Do not run V drive if light is on above 1200 RPM. Does anyone know what this light is an indication of? Is it cooling related, impeller, shaft balance, something else? Mine started coming on intermittently on our last trip to the lake ... thought I'd start with a little trouble shooting on my own before I take it in.