Trailblazer start stop malfunction

I experienced a similar issue with my old 2016 Opel Insignia! Its Eco mode used to cause unexpected engine stalling at traffic lights, even with a fully charged battery. The automatic restart rarely kicked in, and I would have to manually restart the engine each time. Has your car's battery been checked recently? Perhaps it's not providing enough power for the start-stop system to function correctly. Just a thought!

Interesting! The battery seems fine, but I haven’t had it professionally tested yet. When your Insignia had these issues, was it also triggering any errors or warning lights? Or was it simply the engine stalling problem? Wondering if we're dealing with the same underlying gremlin...

Yes, my Insignia displayed a persistent warning light whenever the start-stop system failed! The dealer indicated the battery was suspect. Now that I think about it, they advised me that if the battery couldn't hold sufficient voltage, the start-stop might act erratically or not function at all. To be absolutely sure, I'd suggest a visit to a trusted workshop. They can properly diagnose the root cause for you.

Thank you for the suggestion! I have already scheduled it with the workshop. Apparently, after checking the battery and the error memory, it turned out that my car battery was heavily discharged or defective and had to be replaced. The repair cost is 290€. Now everything seems to be fine again!