Why would the check engine light come on in my 2005 Chevy Uplander?
It’s difficult to determine the exact cause for the check engine light without having the codes pulled. However, because of your fuel gauge malfunction it’s almost certainly the sending unit that’s failing and sending a diagnostic code to the PCM triggering the check engine light. The sending unit itself is located on the top of the tank or worse yet, inside the tank. It won’t be cheap or easy to repair but it also won’t cause any problems with performance, etc. It is however something you will want to have checked out. Left unattended another vehicle function could fail without any notification. The check engine light is not specific and the PCM (vehicle computer) could be holding more than one failure code. Without the sending unit repaired you’d never know if something else “threw” a code. Take it to your local auto parts store first and ask them to pull the codes for you. Most parts stores will do this at no cost to you and will hand over a printout with the diagnostic codes stored
