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"Diagnostic Alert" while truck is off?
Is it possible for my 2021 Silverado to send me a diagnostic alert text message if it is powered off? Last night I received a text message diagnostic alert indicating low air pressure in one of my t...
Mystery solved. Sharing here in case anyone else runs into something similar...
I spoke with an OnStar rep yesterday. After doing a bit of research she informed me that my truck is equipped with an "11th generation" OnStar that will perform a "sleep cycle" diagnostic if powered off between 3-5 days.
The dealership was closed Monday for MLK Day. Since the truck had not been powered on for at least 3 days it must have run the "sleep cycle" diagnostic at nearly 10pm, triggering the text message about my tire having low pressure.