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

Taking Action
Message Indicated on DisplayMazda 6 Owners Manual: Dtc clearing procedure
1. Start the on-board diagnostic test mode.
2. First press the POWER button, then simultaneously press AUDIO CONT button
for 2 seconds or more.
Caution
Before clearing the DTCs, be sure to enter all of them displayed
in the on-board diagnostic test mode in the Audio Repair Order Form. ...
Mazda 6 Owners Manual: Dynamometer
When inspecting and servicing the power train on the dynamometer or
speed meter tester, pay attention to the following:
- Place a fan, preferably a vehicle-speed proportional type, in front
of the vehicle.
- Make sure the vehicle is in a facility with an exhaust gas
ventilation ...