We did not receive an owner's manual, when we purchased the car used. Therefore, although we have changed the oil several times, the "change engine oil" light has remained on since shortly after we purchased the car.
How do I reset the "change engine oil" light, after changing the oil? on 2004 Buick Rendezvous
On the lower left side of dash is the Driver information center with two buttons. Push and release the left one, mode until you see oil life left. Hold down button on the right (reset) until oil life is back to 100%.
Turn the ignition on and press the accelerator fully down and fully up 3 times within 5 seconds. If oil change message flashes it has been reset.