Here's the pdf for the A246E auto trans, but it doesn't show the internal workings, like it does for the manual trans. Reason is, there's a whole separate service manual for auto trans - but it's not being hosted online anywhere.
http://madstyle1972.com/Repair...n.pdfh ... ..0.pdfFor your info, here's the index for most of the 2003 Matrix service manual. It's being hosted by Madstyle - so it might not be available forever. Just click an entry from the index and it will link you to the pdf or service procedure:
http://madstyle1972.com/Repair/Dan, were you planning to do the repair yourself? Tranny work can be real complicated, especially FWD, plus you need specialized tools. If you are, I would suggest buying a copy of the Toyota or Pontiac A246E auto trans manual for about $15-$20. Or else, subscribe to alldatadiy.com for $27/year. With Alldatadiy, you get the complete service manuals for your year and model, including electrical diagrams and all TSB's.