Ok, I had a similar issue come up...read the owners manual and started trying to perform a manual regen. Eventually, I couldn't even get it started. After a lot of trouble shooting, the problem had nothing to do with regen. Turns out the fuel filler neck screen got pushed down just a very slight bit and the fuel gauge float was stuck. My fuel gauge was reading 3/4 full, but was actually empty. I know that makes me look stupid, but I would rather look stupid and possibly help you if it is the same issue, than to keep quiet.