The curtain air bags are mounted in the front and rear window pillars, and the roof edge along both sides.
When the air bag crash sensors detect a side impact of greater than moderate force, the curtain air bag inflates quickly and helps to reduce injury mainly to the rear outboard passenger's head caused by directly hitting interior parts such as a door or window. For more details about air bag deployment, refer to "SRS Air Bag Deployment Criteria".
In a side impact:
Greater than moderate impact to one side of the vehicle will cause the curtain air bag on that side only to inflate.

(With Front Passenger Occupant Classification System) In a roll-over:
In response to a vehicle roll-over, both curtain air bags inflate.

Warning Light/Beep
A system malfunction or operation conditions are indicated by a warning.Refer to Warning/Indicator Lights. Refer to Warning Sound is Activated.
Side Air Bags
SRS Air Bag Deployment CriteriaMazda 6 Owners Manual: Transaxle fluid temperature (tft) sensor removal/installation
Warning
When the transaxle and ATF are hot, they can badly burn. Turn off
the engine and wait until they are cool before replacing the ATF.
1. Remove the oil pan. (See CONTROL VALVE BODY REMOVAL.)
2. Disconnect the TFT sensor connector.
3. Remove the TFT sensor.
4. Install a TFT senso ...
Mazda 6 Owners Manual: Instrument cluster removal/installation
Caution
When replacing the instrument cluster, the configuration procedure must be
performed before removing the instrument cluster. If the configuration procedure
is not performed before removing the instrument cluster, it is possible that the
instrument cluster will not operate normally. ...