Some 2020-2021 Explorer vehicles with 2.3L engine may exhibit a lack of heat from the passenger side vents of the vehicle when using the climate control. When diagnosing for insufficient, erratic or no heat from passenger side vents, perform Workshop Manual (WSM) pinpoint (PPT) tests K, and referred pinpoint tests G/H, and/or AE as applies. If WSM PPT tests are inconclusive, replace heater core per WSM Section 412-00.