Its best to check it from the dip stick on passenger side engine. the panel on dash are light that come on for different reasons like when to change oil, add oil, oil pressure low, these are intended to be used instead of your own judgement in checking to see if your engine needs attention it is simply safety measures. You should be checking and servicing the engine and transmission as normal not going by lights on a panel those are merely back up systems that sound off when they detect a problem. I will add a link below to the owners manual.
Copy & past the URL above you can also print it.
Looking for a Used Tahoe in your area?
CarGurus has 37,897 nationwide Tahoe listings starting at $695.
Search Chevrolet Tahoe Questions
Chevrolet Tahoe Experts