Originally Posted by Gabor Kesseru

I just had this PO0410 problem that started as intermittent and finally turned full on. The dealer diagnosed it as Relay Control Module open, not covered by my full 100K warranty. I balked at the $347 plus labor cost and decided to look into the RCM. I found it in the plastic box next to the battery. Inside the big black box is the bundle/black box that is nearest to the engine. I popped off the cover and saw several open frame relays. Looking closely at the one nearest the firewall I noticed some contact point discoloration. Here's how I fixed it:
1. Disconnect Negative terminal on Battery
2. grind down a small diamond encrusted nail file so it is only about 1/8 inch wide
3. Remove the RCM so you can work on it in a clean and open environment
4. gently file the burnt points
5. reassemble
6. reset the code and check again. If you don't have a code reader, then go to AutoZone or Advance Auto and they will do it for free.
7. Smile if this was the problem, for you just saved $500.

For you Electrical Engineers out there, it failed because the designer skipped using a diode to dissipate the back EMF, as per good relay design. Also, the relay is probably underspecified for this application.
If any of you have the RCM replaced by the dealer, save the old one since all the relays inside this box have the same part number and can be used to fix the RCM the next time it fails (which will happen every 20-40K miles).