Coordination of fuel cutoff for fault detection and hybrid operation

A control method for a hybrid vehicle, the control method comprising:

• selectively generating a request to at least one of:
• transition from providing rich fueling an engine to operating the engine in a fuel cutoff (FCO) state;
• and
• transition from operating the engine in the FCO state to providing rich fueling to the engine;
• in response to a response to the request:
• selectively controlling fueling to the engine to perform the at least one of the transitions;
• and
• selectively determining whether a fault is present in a component of the hybrid vehicle based on the response to the request of the at least one of the transitions;
• controlling an electric motor of the hybrid vehicle using a hybrid control module;
• selectively generating the response using the hybrid control module;
• and
• generating the request when a catalyst temperature is greater than a predetermined temperature.

A control system for a hybrid vehicle, the control system comprising:

• a monitoring module that:
• selectively generates a request to at least one of:
• transition from providing rich fueling an engine to operating the engine in a fuel cutoff (FCO) state;
• and
• transition from operating the engine in the FCO state to providing rich fueling to the engine;
• and
• in response to a response to the request:
• selectively controls fueling to the engine to perform the at least one of the transitions;
• and
• selectively determines whether a fault is present in a component of the hybrid vehicle based on the response to the request of the at least one of the transitions;
• and
• a hybrid control module that controls an electric motor of the hybrid vehicle and that selectively generates the response,
• wherein the monitoring module generates the request when a temperature of an exhaust gas oxygen sensor is greater than a predetermined temperature.

A control method for a hybrid vehicle, the control method comprising:

• selectively generating a request to at least one of:
• transition from providing rich fueling an engine to operating the engine in a fuel cutoff (FCO) state;
• and
• transition from operating the engine in the FCO state to providing rich fueling to the engine;
• in response to a response to the request:
• selectively controlling fueling to the engine to perform the at least one of the transitions;
• and
• selectively determining whether a fault is present in a component of the hybrid vehicle based on the response to the request of the at least one of the transitions;
• controlling an electric motor of the hybrid vehicle using a hybrid control module;
• selectively generating the response using the hybrid control module;
• and
• generating the request when a temperature of an exhaust gas oxygen sensor is greater than a predetermined temperature.