Hyundai Repair: malfunction indicator light 2003 Santa Fe Hyundai, malfunction indicator light, transmission control module tcm

Question
What does this check light mean?

Answer
The check engine lamp simply indicates that the engine control module (ECM) or transmission control module (TCM) has seen something abnormal.  

If the lamp is on steady and the vehicle still drives normally, you're typically okay to continue driving for a reasonable amount of time until the vehicle is diagnosed and repaired.  If the lamp is flashing, it indicates that catalyst damage is likely, and you should not drive the vehicle.  If the vehicle isn't running properly, it may put you in a hazardous situation.  In this case, you also should not drive the vehicle.

If you'd like to know the specific nature of the problem, you'll need to either take the car in for repair or have the diagnostic trouble codes read and follow up with them here.  I'll be interested in the codes themselves, not the mechanic's or code reader's interpretation of what they mean.  AutoZone and AAMCO have advertised they'll check the diagnostic trouble codes for free.