I've searched all over the place for this, and I see tons of evidence that people are getting the CEL codes on their Hondas, but can't find any info on how to do it. On the wife's 2005 Grand Caravan it's simple: just on-off-on-off-on with the ignition key and it displays the code(s) on the odometer. Tried that on the 2007 Odyssey, and it didn't do anything.