Take the appropriate action and verify that the warning light turns off.

Taking Action
Message Indicated on DisplayMazda 6 Owners Manual: No. 2 all on-board diagnostic functions inoperative
When performing an asterisked (*) troubleshooting inspection, shake the
wiring harness and connectors while doing the inspection to discover whether
poor contact points are the cause of any intermittent malfunctions. If there
is a problem, check to make sure connectors, terminals and wir ...
Mazda 6 Owners Manual: Cup Holder
WARNING
Never use a cup holder to hold hot liquids while the vehicle is moving:
Using a cup holder to hold hot liquids while the vehicle is moving is dangerous.
If the contents spill, you could be scalded.
Do not put anything other than cups or drink cans in cup holders:
Putting objects othe ...