He has an OBD-2 vehicle. I don't think the jumper trick will work.Gairloch said:Can even do one better. Our cars are OBD I so you can pull the code by using a paperclip to jumper the TE1 and E1 terminals on the diagnostic box then count the flashes of the CEL. You can find a more in depth explanation of the procedure and a list of code definitions here: http://www.off-road.com/toyota/tech/codes/. You can find the diagnostic box in the engine bay driver's side on the trunk firewall.
I am 99% sure that the fuel tank lid doesn't have any sensors on it.