METHOD FOR DETECTING HEATER CORE ISOLATION VALVE STATUS

Methods and systems are provided for monitoring a status of a heater core isolation valve (HCIV) housing in an engine coolant circuit including a first coolant loop and a second coolant loop. In one example, a method may include indicating degradation of the HCIV based on a difference between a first coolant loop temperature and a second coolant loop temperature upon activation of coolant system pumps and deactivation of a positive temperature coefficient (PTC) heater housed in the cabin heating loop.