HOW DO YOU CHANGE THE OIL LEVEL ON THE COMPUTER FOR A 2003 CHEV TRAILBLAZER. IT IS ALL COMUTERIZED AND I HAVE TRIED WORKING WITH THE BUTTONS BUT IT DOES NOT WORK, WHAT AM I DOING WRONG. MY FRIEND CHANGED THE OIL BUT NOW THE COMPUTER NEEDS TO BE CHANGED TO READ SAME

Ok you cant change the oil level, you need to reset the oil change light, right???. Scroll until it reads OIL LIFE , now find the button that looks like a backwards "L" with an arrow on the lower leg, now hold that button in until the oil life resets. Oil life is based on the correct oil used, be sure it meets GM 6094 Spec. If its not synthetic, its not good enough.

You can also turn the ignition switch to run and pat the gas pedal 3 times within 5 seconds. the oil change light should blink 5 times to indicate that oil life has been reset, if it dosen't turn key off and repeat.