I had my hybrid water pump replaced (free, under recall) about a month ago. Now the check engine light comes on intermittently, and it's with error code 1121 (Coolant flow control valve sensor stuck). I've seen other people on this forum hypothesize that the work could cause this error (if not bled properly, leaving air in the system). But my dealer said the work had nothing to do with this error and I need to replace the control valve ($100 part and $400 labor). Any ideas on how to suggest to my dealer that it could, in fact, be due to their work and that I think they should fix it for free?