Selective catalytic reduction catalyst pre-heating and exhaust burner air control

1. An exhaust control system of a vehicle, comprising:

a fuel injector configured to inject fuel into a combustion chamber of a burner of an exhaust system upstream of a selective catalytic reduction (SCR) catalyst;

an air pump configured to pump air into the combustion chamber of the burner via an air supply line;

a spark plug configured to ignite an air/fuel mixture within the combustion chamber of the burner;

a fuel control module configured to, while an engine is off before an engine startup, selectively actuate the fuel injector and begin fuel injection;

a pump control module configured to, while the engine is off before the engine startup, selectively turn on the air pump;

a spark control module configured to, while the engine is off and before the engine startup, selectively apply power to the spark plug and begin providing spark; and

an air valve that receives air from the air pump via the air supply line, wherein a valve control module is configured to control the air valve, when open, to output air to a second location that is different than the combustion chamber of the burner while the engine is off before the engine startup, wherein the air supply line includes a branch positioned upstream of the air valve.

2. The exhaust control system of claim 1 further comprising a startup module configured to selectively generate an engine startup signal before the engine startup,

wherein:

the fuel control module is configured to, while the engine is off before the engine startup, actuate the fuel injector and begin fuel injection in response to the generation of the engine startup signal;

the pump control module is configured to, while the engine is off before the engine startup, turn on the air pump in response to the generation of the engine startup signal; and

the spark control module configured to, while the engine is off and before the engine startup, apply power to the spark plug and begin providing spark in response to the generation of the engine startup signal.

3. The exhaust control system of claim 2 wherein the startup module is configured to generate the engine startup signal in response to a determination that a distance between a mobile device and the vehicle transitioned from (a) greater than a predetermined distance to (b) less than the predetermined distance.

4. The exhaust control system of claim 3 further comprising a wireless transceiver module configured to:

wirelessly communicate with the mobile device; and

determine the distance between the mobile device and the vehicle based on signals received from the mobile device.

5. The exhaust control system of claim 2 wherein the startup module is configured to generate the engine startup signal in response to unlocking of one or more doors of the vehicle.

6. The exhaust control system of claim 3 wherein the mobile device is a key fob.

7. The exhaust control system of claim 2 wherein the startup module is configured to selectively generate the engine startup signal based on a present time.

8. The exhaust control system of claim 2 wherein the startup module is configured to generate the engine startup signal in response to a determination that a predetermined period passed after a user exited the vehicle.

9. The exhaust control system of claim 1 further comprising:

a diesel emissions fluid (DEF) injector configured to inject a DEF into the exhaust system upstream of the selective catalytic reduction (SCR) catalyst; and

a DEF control module configured to, while the engine is off before the engine startup, selectively actuate the DEF injector and begin DEF injection.

10. The exhaust control system of claim 9 wherein the DEF control module is configured to, while the engine is off before the engine startup, selectively actuate the DEF injector and begin DEF injection in response to a determination that a temperature of the SCR catalyst is greater than a predetermined temperature.

11. The exhaust control system of claim 10 wherein the DEF control module is configured to, while the engine is off before the engine startup, not actuate the DEF injector and not perform DEF injection when the temperature of the SCR catalyst is less than the predetermined temperature.

12. The exhaust control system of claim 1 further comprising a flame sheath including:

an inner surface that defines the combustion chamber; and

an outer surface,

wherein the second location is adjacent to the outer surface of the flame sheath.

13. The exhaust control system of claim 1 wherein the second location is downstream of the combustion chamber.

14. An exhaust control method for a vehicle, comprising:

by a fuel injector, selectively injecting fuel into a combustion chamber of a burner of an exhaust system upstream of a selective catalytic reduction (SCR) catalyst;

by an air pump, selectively pumping air into the combustion chamber of the burner;

by a spark plug, selectively igniting an air/fuel mixture within the combustion chamber of the burner;

by a valve, selectively receiving air from the air pump and, when open, outputting air to a second location different than the combustion chamber of the burner;

while an engine is off before an engine startup:

actuating the fuel injector and beginning fuel injection;

turning on the air pump;

applying power to the spark plug and beginning to provide spark; and

at least partially opening the valve to pump air to the second location.

15. The exhaust control method of claim 14 further comprising a selectively generating an engine startup signal before the engine startup,

wherein:

the actuating the fuel injector and beginning fuel injection includes actuating the fuel injector and beginning fuel injection in response to the generation of the engine startup signal;

the turning on the air pump includes turning on the air pump in response to the generation of the engine startup signal; and

the applying power to the spark plug and beginning to provide spark includes applying power to the spark plug and beginning to provide spark in response to the generation of the engine startup signal.

16. The exhaust control method of claim 15 wherein the selectively generating the engine startup signal before the engine startup includes generating the engine startup signal in response to a determination that a distance between a mobile device and the vehicle transitioned from (a) greater than a predetermined distance to (b) less than the predetermined distance.

17. The exhaust control method of claim 16 further comprising:

wirelessly communicating with the mobile device; and

determining the distance between the mobile device and the vehicle based on signals received from the mobile device.

18. The exhaust control method of claim 15 wherein the selectively generating the engine startup signal before the engine startup includes generating the engine startup signal in response to unlocking of one or more doors of the vehicle.

19. The exhaust control method of claim 15 wherein the selectively generating the engine startup signal before the engine startup includes generating the engine startup signal at least one of:

based on a present time; and

in response to a determination that a predetermined period passed after a user exited the vehicle.