How do you reset the check engine light on a 2003 gmc yukon xl

GM Security lockout reset procedure
https://www.youtube.com/watch?v=5feL05TyLtI

https://www.2carpros.com/questions/2003-gmc-yukon-xl-5-3-vortec-anti-theft-deterent-light-on-dash-board-stays-solid-2

owners manual
https://my.buick.com/content/dam/gmownercenter/gmna/dynamic/manuals/2003/gmc/yukon_xl/2003_gmc_yukon_denali_xl_owners.pdf
what is the purpose
https://www.quora.com/What-is-the-purpose-of-the-flashing-red-LED-light-on-the-dashboard-of-cars

2003 GMC Yukon XL check engine light run - YouTube

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www.youtube.com/watch?v=Rt06jXNGJT0
Mar 31, 2014 - Uploaded by Antonio Salinas
2003 GMC Yukon XL with a check engine light on. ... HOW TORESET CHECK ENGINE LIGHT, FREE EASY ...

May need a new alternator

I'll try to help, everytime something gets replaced on these yukons, that circuit needs to be RESET ! Is there a reset button, on your steering wheel, to reset a variety of functions ? , check owners manual, or call your dealer for better advise

What size engine ? 4.3 L vortex P0300 random misfire code is usually associated with vacuum leaks , but could also be low fuel pressure , plugged fuel filter , fuel pump problem , clogged injectors etc... doing fuel pressure an flow testing would confirm or eliminate that as a problem . Fuel injector balance testing would confirm or eliminate clogged injectors .

jeeze, so many "common" causes. but THE most likely cause is an oxygen sensor out of range. replacing same and driving several miles might get you lucky and save some money. but note, a restricted fuel or air filter will likewise make this sensor report bad data and set the same code. in other words, don't ignore maintenance issues...

Probably carbon build up on a sensor. Had this happen on a Ford Expedition. I put it on the highway and hammered it several times. It blew the carbon off the sensor. Light went away.

If it is anything like the 2003 you turn your car to the on position without running the engine, tap the accelerator 3 times very quickly in less than 5 minutes. This should reset your back to 0 for your next oil change.

you have to take it to a auto part store and they can tell you if there are any problems using a key code and then reset it

I had the same problem with my 2003 denali and came to find out that it was the battery causing the problem. the battery with sufficient power will dictate the tps. if the battery is low or bad, it won't have enough juice to allow the tps to. work. get your battery checked.