GMC Yukon Denali Xl 1500
Problems & Worst Years

Brake and tail light failures dominate both model years on file for the GMC Yukon Denali XL 1500. 2016 is the far larger file at 417 occurrences across 12 problems, one safety-rated, led by 116 reports of intermittent brake light failure — itself safety-rated — plus 74 describing tail light assembly failure requiring expensive replacement and another 51 under a near-identical description. A further 37 reports describe a faulty rear brake light assembly specifically, meaning lighting complaints of one kind or another account for well over half of everything filed against this model year. Transmission shuddering and hard shifting adds 43 more reports.

2017 volume drops to 117 occurrences across 9 problems, none safety-rated, but the same lighting theme persists: brake light failure leads at 43 reports, followed by 22 describing air conditioning failure and 12 more general electrical lighting issues. Transmission issues (11) and engine stall paired with rough running (10) round out the year.

Because brake and tail light problems recur so heavily across both years — and because a failed brake light carries obvious safety implications for a vehicle this size — cycling every exterior light through a full check, including at night, is the single most useful pre-purchase step here, on top of the usual test drive for transmission shudder and engine roughness. Given that replacement was specifically flagged as expensive in some reports, it's also worth asking whether the tail light assemblies have already been addressed.

As with the rest of this hub, these figures represent what owners chose to report to NHTSA rather than a precise, measured failure rate, and the sharp drop in complaints from 2016 to 2017 may reflect a real fix as easily as it reflects fewer miles accumulated. A pre-purchase inspection and documented service history on the specific SUV remain the more reliable signal than the model year alone.