limp mode no communication between tcm/ecm since overheating

Hi, I'm one of the auto experts on RepairPal's Car Genius team! Great question, and thanks for the detail! On your 2013 Jeep Patriot, a loss of communication between the TCM and ECM following an overheating event is a serious concern. Extreme heat can damage control modules internally even when the wiring checks out perfectly, and unfortunately the TCM or ECM themselves may have suffered heat related damage that isn't visible through wiring tests alone. The CVT transmission on this generation Patriot is also particularly sensitive to overheating and can sustain internal damage that puts it into a permanent limp mode as a protective measure. The modules also communicate with each other via CAN bus, so just because the wires test out, doesn’t eliminate a communication breakdown via can bus. The next step would be having a qualified shop with proper scan tools attempt to communicate directly with both modules individually to determine if one or both have been damaged and need replacement or reprogramming. This is unfortunately not a repair that really lends itself to DIY diagnosis beyond what you've already done. If you’d like to find a trusted, certified repair shop in your area, you can check here: https://repairpal.com/certified If you need more advice, or have any further questions about your vehicle, we’re here to help. Just give us a call at 877-913-1554