Abstract: Methods and systems are provided for a vehicle coolant circuit. In one example, the coolant circuit includes a heater core isolation valve (HCIV) where a status of the HCIV may be diagnosed by intrusively activating a positive temperature coefficient heater in a cooling loop in which the HCIV is arranged. A response of coolant temperature to heater activation may be used to determine a position of the HCIV.

Abstract: Methods and systems are provided for an EGR system reverse hose diagnostic. In one example, a method includes executing the reverse hose diagnostic in response to an EGR flowrate exceeding a threshold flow rate.

Abstract: Methods and systems are provided for an EGR system reverse hose diagnostic. In one example, a method includes executing the reverse hose diagnostic in response to an EGR flowrate exceeding a threshold flow rate.

Abstract: Methods and systems are provided for a vehicle coolant circuit. In one example, the coolant circuit includes a heater core isolation valve (HCIV) where a status of the HCIV may be diagnosed by intrusively activating a positive temperature coefficient heater in a cooling loop in which the HCIV is arranged. A response of coolant temperature to heater activation may be used to determine a position of the HCIV.

Abstract: Systems are provided for a fuel system comprising an external refueling request switch accessible at or near a refueling door, thus enabling methods that may include initiating depressurization of a fuel tank responsive to an operator engaging the refueling request switch. The status of depressurization may be communicated to the operator via on one or more LED displays located either inside the refueling assembly or located at the refueling door. In this way, refueling requests may be initiated by a refueling operator, and by relaying the status of depressurization to the operator, any confusion on the part of the operator may be avoided.

Abstract: Systems are provided for a fuel system comprising an external refueling request switch accessible at or near a refueling door, thus enabling methods that may include initiating depressurization of a fuel tank responsive to an operator engaging the refueling request switch. The status of depressurization may be communicated to the operator via on one or more LED displays located either inside the refueling assembly or located at the refueling door. In this way, refueling requests may be initiated by a refueling operator, and by relaying the status of depressurization to the operator, any confusion on the part of the operator may be avoided.

Abstract: A system and method are provided for analyzing a motor vehicle operating problem. A number of tests are provided for the selected system or component to determine the cause of the problem. One of the tests are selected, and instructions are displayed for the selected test. A result is input for the selected test and it is determined whether the result indicates the problem was experienced during the test. If the problem was not experienced and that the test did not experience a failure, the state of the faults that are detectable by the test are set to substantially “Possible Intermittent Fault”.