Hey Scotty,
I have just purchased a 2021 GMC Sierra with the 3.0L Duramax diesel. At just under 1000km while out doing some running around, I went to start the truck and it took three crank attempts to get it started. It then had the check engine light stay on solid, not flashing, each time I tried to start it that day. The next morning, no engine light, but I still contacted the dealership and booked an appointment to get it checked. Showed up for my appointment two days later and the service counter guy told me that if the light isn't currently on, they won't be able to diagnose anything!!!! Does the ECU not store any codes that are created? No engine light since then and the engine seems to be running normal. I'm more concerned with the quick dismissal by the dealership than I am with the engine light. Can you clarify any of this for me?
Robyn
You need to find someone who can scan it for the codes. Try one of the large auto supply chains that will do it for free. They may be able to pull up a stored code if there isn't anything showing now.
