99 gmc oil light flashing

Place a piece of black electrical tape over it ,problem solved .you know the oil is good

Hello,

1. Turn the ignition to run (one position before starting engine).
2. Immediately after Step 1 press and release the gas pedal 3 times within 5 seconds.
3. If the Change Oil Soon light flashes the system is resetting.
4. Turn the ignition off and then start the engine to verify the indicator has been reset.

TO RESET CHANGE OIL LIGHT.TURN IGNITION SWITCH TO RUN POSITION WITH ENGINE OFF.PRESS ACCELERATOR PEDAL QUICKLY 3 TIMES IN 5 SECONDS.THE OIL LIGHT WILL FLASH WHEN IT HAS RESET.

This light needs to be reset when the oil is changed. To reset, do the following:
1. turn key to 'run' position with engine OFF
2.fully press and release the gas pedal 3 times in 5 seconds or less
3.light should now flash, which means it is reset. Light will go off in 30 seconds, or when key is turned off.

turn ignition switch to on or run position with engine off press accelerator pedal slowly to wide open throttle 3 times within 5 seconds change oil light will flash 5 second if not retry

turn key to on position (DO NOT START)
press and release gas pedal 3 times.
leave key on the change engine oil light flashes 5 times than goes away and its reset

The place that changed your oil should have done this for you

to manually reset it , turn the key to the on position with the engine off , depress the accelerator pedal 3 times slowly to the floor within 5 seconds , if change engine oil flashes for 5 seconds oil life monitor is reset ...

if the vehicle is equipped with a driver information center , reset the oil monitor by pressing driver information center SELECT button for 5 seconds while Engine Oil Life is displayed .

as soon as you turn key on hit the gas pedal 3 times really fast you may need to do this a couple of times

Its pretty simple, and you can do it in a few seconds...
Turn the key to ON (not crank) and within the first 5 seconds you have to step on the gas pedal all the way to the floor 3 complete times...
you will see the light flash 3-5 times and then go out... its reset for 3,000 miles or sooner based on driving habits...