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

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.