GMC Yukon XL Denali Owner's Manual page 421

Windshield
For safety, appearance, and the
best viewing, keep the windshield
clean and clear.
Signs of damage include
scratches, cracks, and chips.
Trained dealer technicians can
inspect the windshield and
recommend proper replacement
if needed.
Wiper Blades
Wiper blades need to be cleaned
and kept in good condition to
provide a clear view.
Signs of wear include streaking,
skipping across the windshield,
and worn or split rubber.
Trained dealer technicians can
check the wiper blades and
replace them when needed.
Service and Maintenance 11-11