Or maybe he confused the MIL with the maintenance required lamp.

MIL ("Malfunction Indicator Lamp") is the proper official name for the CEL (according to the Helm book).

Still, the original confusion was a coincidence. The maintenance lamp flashing 10 times simply means you're getting close to a maintenance interval. Just so happens that his actual error code was for the IAT.

jjcorreia...
In order to watch the check-engine lamp flash its code, you have to jumper the SCS connector. And the button in the cluster can't be used to clear a check-engine lamp.