Pin 2 is used to check for any diagnostic codes stored by the ECU (fuel injection module). You also need to check pin 6 for any diagnostic codes stored by the ICU (ignition module). I'm not sure if your year also uses pin 3 to check the ABS system (look for a wire hooked to the back of that pin on the socket).

You are right in that 1-1-1 is the "no fault" code. Each unit can store multiple codes. If the first code is 1-1-1 then all is well. If you get anything else then keep reading the additional codes until you get 1-1-1 or the first code repeats. Each unit has to be reset separately unless you use the battery disconnect method. After reading any codes, if your car is running okay then reset the codes and let them re-appear before jumping to any conclusions -codes sometimes get set for transient conditions. Also, not all codes cause the Check Engine light to come on.

See the 700/900 FAQ feature section on this site for help on reading, interpreting and resetting the codes. It is important to note that a code description may say a particular condition occurred (such as an O2 sensor reading out of range), but that does not necessarily mean that particular component has failed and something else may have caused the condition (such as an intake air leak or a bad control pressure regulator). The Check Engine light should not come on then go away on its own (however the Service reminder light does do that).
--
Dave -not to be confused with a real expert, just goofing around at this