CMAX Overheating Communication Error

My 2018 Ford CMAX diesel with 62,000 km is overheating badly. The check engine light is on, and there's coolant under the car after driving, suggesting excessive cooling system pressure. I'm also getting a control unit communication error. Coolant level and radiator fan are fine. Could it be a CAN bus cable, a component plug connection, or a software glitch? Has anyone else seen this?

4 comment(s)

Sounds familiar. I've got a CMAX, and had a similar overheating issue last year. Engine light was on, but I didn't see any coolant leaks. Did you check for any damage to the wiring harness around the engine? Rodents sometimes chew on those.

Thanks! I visually inspected the wiring harness, but it's tight in there. Was your issue also a control unit communication error, or something else entirely? Trying to narrow things down before I start tearing into it.

Control unit was the culprit, or so the workshop said. I didn't dig too deep. I'd suggest getting it checked by a professional. They'll have the right tools to diagnose it properly. Could save time and frustration.

Appreciate the insight! You were spot on. The shop found a defective cable/plug connection to a component causing the communication error. Cost 95€ to fix. Thanks for pointing me in the right direction!

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