1. Remove the door switch. (See DOOR SWITCH REMOVAL/INSTALLATION)
2. Inspect for continuity between the door switch terminal and a body ground using an ohmmeter.


Door switch removal/installation
Ashtray illumination bulb removal/installationMazda 6 Service Manual: Contact Authorized Mazda Dealer and Have Vehicle Inspected
If any of the following warning lights or the indicator light turns on/flashes,
the system may have a malfunction. Contact an Authorized Mazda Dealer to have your
vehicle inspected.
...
Mazda 6 Service Manual: Snow Tires
Use snow tires on all four wheels
Do not go faster than 120 km/h (75 mph) while driving with snow tires. Inflate
snow tires 30 kPa (0.3 kgf/cm2, 4.3 psi) more than recommended on the tire pressure
label (driver's door frame), but never more than the maximum cold-tire pressure
shown on the tir ...