You cannot help but notice high-intensity discharge (HID / Xenon) and light-emitting diode (LED) headlights—the light they produce is noticeably brighter and whiter than halogen headlights. These high-tech headlights have become a signature look of aftermarket upgrades, and they distinguish the styling on many new vehicles. To upgrade the lights on Chevy Tahoe you will need to know the correct bulb sizes.
2002-2006 Chevrolet Tahoe vehicles all use the same bulb size for the Low Beams (9006), High Beams (9005), and Fog Lights (880 bulb).
2007-2014 Chevrolet Tahoe vehicles use exact same bulbs for the Low Beams (H11), High Beams (9005), and Fog Lights (5202 bulb).
2015-2018 Chevrolet Tahoe with Halogen headlights Low Beams (H11), High Beams (9005), and Fog Lights (5202 bulb); while with HID capsule uses D3S bulb size for its Low Beams.
Flickering may be caused by aftermarket bulbs drawing less power than the factory ones, especially when it comes to the newest vehicles. The most common case is when the Daytime Running Lights are the same bulbs, which you are upgrading. 9005 performs the function of high beams and DRL on Chevrolet Tahoe 2015-2016 (with Halogen headlights). To resolve this issue - an installation of a relay harness may be needed.
Reversed polarity issue is common for Chevy's, it has also been reported for other models. Chevrolet Tahoe has often reversed polarity on low beam plugs which causes the lights not to turn on. You should rotate the 2-pin oval connector between the ballast and bulb (or simply an LED power wire) by 180 degrees and plug it back to resolve this issue. Please, do this on both sides.
Automatic Lights influence the work of Low Beams on Chevrolet Tahoe (2002-2013). Note that using Auto Switch mode may not work correctly with aftermarket lights with any particular vehicle’s setup. To disable Automatic lights, you need to turn your Auto Switch to “Manual” position.