WARNING
Do not leave the key in your vehicle with children and keep them in a place where your children will not find or play with them:
Leaving children in a vehicle with the key is dangerous. This could result in someone being badly injured or even killed. Children may find these keys to be an interesting toy to play with and could cause the power windows or other controls to operate, or even make the vehicle move.
CAUTION
A code number is stamped on the plate attached to the key set; detach this plate and store it in a safe place (not in the vehicle) for use if you need to make a replacement key (auxiliary key).
Also write down the code number and keep it in a separate safe and convenient place, but not in the vehicle.
If your key (auxiliary key) is lost, consult your Authorized Mazda Dealer and have your code number ready.
NOTE
The driver must carry the key to ensure the system functions properly.

To use the auxiliary key, pull out the auxiliary key from the transmitter while pressing the knob.

Keys
Keyless Entry SystemMazda 6 Owners Manual: System wiring diagram
ABS (ABS/TCS)
DSC
FOREWORD
Before performing the steps in Symptom Troubleshooting, perform the
On-board Diagnostic Inspection. To check the DTC, follow the DTC Inspection
steps.
...
Mazda 6 Owners Manual: Starting a Flooded Engine
If the engine fails to start, it may be flooded (excessive fuel in the engine).
Follow this procedure:
1. If the engine does not start within five seconds on the first try, wait ten
seconds and try again.
2. Make sure the parking brake is on.
3. Depress the accelerator all the way and hold it ...