Magnum Diesel Overheating + Coolant Leak Mystery

As a Dodge Durango 2011 Diesel owner, I encountered similar symptoms. The diagnostic trouble code pointed to a control unit connectivity issue, which initially masked the real problem. After thorough car diagnostics, it turned out the water pump had failed, causing both the overheating and coolant leak. The data link communication error was actually a secondary issue caused by the engine temperature sensor malfunction. The overheating problem requires immediate attention since it can lead to severe engine damage. Common causes in these Dodge models include: Failed water pump, Damaged radiator, Faulty thermostat, Cracked coolant reservoir, Loose or damaged cooling system hoses My recommendation is to get a second opinion from a shop specializing in Dodge vehicles. They should perform a pressure test on the cooling system and verify the data link between the control unit and engine sensors. This was a serious repair job requiring multiple components replacement in my case. The check engine light staying on suggests the control unit is detecting ongoing issues. A professional diagnostic scan tool should be able to read the specific trouble codes to pinpoint the exact problem.

Thanks for sharing your experience. In my case with the Magnum, I had nearly identical symptoms, the overheating, leaks, and communication fault that kept throwing off the diagnostics. I also discovered it was ultimately the water pump, but only after getting a proper CAN bus diagnostic that revealed the wiring issue was a secondary problem. How much did the complete repair end up costing you? Have you experienced any cooling system problems since the fix? Just want to compare notes since these issues seem common in our models.

Good to hear back about your Magnum. The control unit communication error on my Durango was completely resolved after getting it checked by a specialist. They discovered the CAN bus diagnostic was being affected by a loose cable connection near the engine temperature sensor. The repair was straightforward, just 95€ to fix the faulty wiring connection. Since fixing both the water pump and the data link communication issue, the cooling system has been running perfectly. No more software glitches or overheating problems for the past year. The key was finding a shop that could properly diagnose both the mechanical cooling issue and the electronic communication fault simultaneously. My advice would be to keep monitoring your engine temperature gauge even after repairs, just to ensure everything stays properly calibrated. These control unit communication problems can sometimes mask underlying issues, but once properly fixed, they typically dont return.

Following the troubleshooting and advice received here, I finally got my Magnum properly diagnosed and fixed. After visiting a specialized shop with advanced CAN bus diagnostic equipment, they confirmed both the water pump failure and the control unit communication problem. The entire repair came to 850€, including parts and labor. The communication fault turned out to be caused by corroded wiring near the temperature sensor, which was triggering false readings to the control unit. The mechanic replaced the water pump, fixed the wiring harness, and performed a complete cooling system flush. The software glitch cleared up once the new components were properly connected. Its been running great for the past three weeks, no more overheating, leaks, or check engine lights. The shop also showed me exactly where the connectivity issue was occurring, which helped me understand why the initial diagnosis was so challenging. Really glad I got that second opinion from a specialist who understood both the mechanical and electronic systems.