Jaguar XK Cooling System Failure & ECU Warning Alert

Had a similar situation with a 2014 Jaguar XF. The symptoms started exactly like yours, rising engine temps and coolant loss. The initial diagnosis revealed a communication fault between the engine control module and cooling system control unit. The root cause turned out to be corroded wiring connectors affecting the CAN bus network, which disrupted data link communication between multiple control modules. The coolant temperature sensor was sending erratic signals, causing the system to malfunction. This was a serious issue requiring careful diagnosis. The repair involved: testing all control module communication paths, Replacing damaged wiring harness sections, cleaning and resealing multiple connector pins, Reprogramming the engine control unit A flashing check engine light often indicates a severe problem that could damage the catalytic converter. The trouble codes you might see could be P0217 (engine overheat condition) or U0100 (lost communication with ECM/PCM). Recommend getting it diagnosed soon, as continued overheating can lead to engine damage. Make sure the shop has proper diagnostic equipment for Jaguar control modules and CAN bus testing.

Thanks for sharing your detailed account of the wiring issue. Your situation sounds nearly identical to mine, especially with those data link communication problems showing up. Just checking, do you remember roughly what you paid to get everything sorted? Also curious if youve had any other cooling or control module problems since the repair was done. Trying to get a sense of whether this tends to be a one-time fix or if I should watch out for it happening again. Would be really helpful to know before I head to the shop with my XK. The diagnostic trouble codes youve mentioned definitely match what Im seeing.

Just wanted to follow up on the repair costs, got everything sorted last week for 95€ at the shop. The mechanic found a faulty cable connection that was causing the control unit communication error, which explained all those cooling system warnings we were seeing. Since fixing that connectivity issue between the modules, the car has been running perfectly. No more trouble codes, temperature stays normal, and the check engine light hasnt come back on. The software glitch disappeared once they repaired the damaged wiring connection. This type of control module communication problem usually stays fixed once properly repaired. Just make sure your mechanic thoroughly tests all the connections, thats what made the difference in my case. The diagnostic trouble codes cleared right up after addressing that single failing connector. For what it was, the repair cost was pretty reasonable considering it resolved both the cooling and communication issues. Its been about 8 months now with zero problems.

Thanks for the helpful replies. I finally got my XK checked out and wanted to share how it went. Took it to a specialized shop that had the right car diagnostics equipment. The mechanic found exactly what was described, faulty wiring affecting the control module communication. The CAN bus system was throwing multiple errors due to water damage on one of the main connectors. Total repair came to 850€, which included: Full system diagnostic scan, Replacement of damaged wiring harness, cleaning and sealing all control unit connections, Coolant system pressure test, Software update for the engine control module Car has been running perfectly for the past 2 weeks. Temperature gauge stays steady and no more coolant leaks. The check engine light cleared up as soon as they fixed the communication fault. Really glad I asked here first, helped me understand the problem and made sure the shop did a proper diagnosis instead of just topping up coolant and sending me on my way.