RepairPal Certified shops can diagnose and repair your 2015 Dodge Journey. They provide transparent pricing with a minimum 12-month or 12,000-mile warranty on repairs and services.
Couple of 'possibilities' .. Defective heater control valve not closing thus allowing free flowing hot coolant to rear heater.... Failed rear A/C expansion valve blocking freon flow .. Neither of which is a DIY repair!
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Do you know how long these repairs usually take?
Possibly warranty repair - depending on mileage.... Can't say how long it'll take another shop to complete repairs.