Technical Service Bulletin N182202780 01 — 2015 GMC YUKON XL

N182202780 01 - Special Coverage. Certain Vehicles may have a condition where customers may experience increased brake pedal effort, hardbrake pedal, and/or potentially increased stopping distance. The condition is more prevalent at low speed when softly applyingthe brakes. The engine mounted mechanical vacuum pump outputmay decrease over time decreasing the amount of vacuum/power brake assist. Failure to follow recommended oil change intervalscould contribute to this condition. The Driver?s Information Center, (DIC) ?Service brake assist? alert will activate 2-5minutes after the vacuum level drops, and a Diagnostic Trouble Code, (DTC) will also be set. Even where this condition occurs,the hydraulic brake system remains functional but may require additionalpedal force. Please be aware that even if the vehicle exhibits this condition, it meets all federal motor vehicle safety standards forbrake performance. Dealers are to replace the vacuum pump and vacuum pump belt. The repairs will be made at no charge to the customer.