GM Repair Questions? Ask a Mechanic for Answers ASAP
You will need to do a actual oil pressure test with a mechanical guage to see if its low. If it is low then you can start by doing a engine flush then checking the pickup tube to see if its clogged. If not replace the oil pump, and if problem is still there you have a internal engine problem causing low pressure such as worn bearings. If oil pressure is good bring it to the dealership to have them reflash the Instrument Panel Cluster (IPC) with the latest update per TSB #01-08-49-006. Let me know if you have questions, thanks.