Controlling of a vehicle responsive to reductant conditions

A method for controlling a vehicle having an engine with an exhaust, the exhaust having a reductant injection system including a reductant storage vessel, the engine further having a fuel system including a fuel storage vessel, the method comprising:

• when degraded reductant conditions are present, limiting vehicle speed to a first vehicle speed limit;
• after a restart following the limitation at the first vehicle speed limit in which degraded reductant conditions are still present, limiting vehicle speed to a second vehicle speed limit;
• and
• after a restart following the limitation at the second vehicle speed limit in which degraded reductant conditions are still present and in which the fuel storage vessel has been refilled beyond a threshold fuel level, restricting motion of the vehicle to non-moving condition while enabling engine idling operation and enabling HVAC operation.

A method for controlling a vehicle having an engine with an exhaust, the exhaust having a reductant injection system including a reductant storage vessel, the engine further having a fuel system including a fuel storage vessel, the method comprising:

• when an amount of a proper urea reductant stored in the reductant storage vessel is less than a threshold amount, issuing a first warning message indicating a first vehicle speed limit to be applied;
• if the amount of the proper urea reductant stored in the reductant storage vessel is still less than the threshold amount, limiting vehicle speed to the first vehicle speed limit;
• after a restart following the limitation at the first vehicle speed limit in which the amount of the proper urea reductant stored in the reductant storage vessel is still less than the threshold amount and after a selected duration, issuing a second warning message indicating a second vehicle speed limit to be applied, and if the amount of the proper urea reductant stored in the reductant storage vessel is still less than the threshold amount, limiting vehicle speed to the second vehicle speed limit;
• after a restart following the limitation at the second vehicle speed limit in which the amount of the proper urea reductant stored in the reductant storage vessel is still less than the threshold amount, issuing a third warning message indicating restriction of motion to be applied upon detecting a refueling event;
• and
• if the amount of the proper urea reductant stored in the reductant storage vessel is still less than the threshold amount and upon detecting the refueling event, restricting motion of the vehicle to non-moving condition while enabling engine idling operation and enabling HVAC operation.