2015 GMC Yukon Denali

On November 20, 2018, the Office of Defects Investigations (ODI) opened PE18-012 to investigate instances of sudden onset of a hard brake pedal that could result in extended stopping distance due to an issue with the brake assist vacuum pump in model year (MY) 2014 through 2016 GMC Sierra 1500 and Chevrolet Silverado 1500 series pickup trucks and MY 2015 through 2016 Cadillac Escalade, Chevrolet Suburban, Chevrolet Tahoe, and GMC Yukon SUVs.If the brake assist vacuum pump fails to operate as intended, the amount of brake power assist supplied to the driver can be significantly reduced, extending the subject vehicle stopping distance. GM stated that the root cause of pump failures was due to foreign debris such as oil sludge in the engine oil. GM stated that this debris can become trapped by the oil inlet filter screen. Under normal operation, this screen allows a small amount of oil into the brake vacuum pump. The foreign debris can, over time, clog the pump which can cause a loss of lubrication and a reduction in the amount of vacuum produced leading to a hard pedal and extended stopping distance.On December 13, 2018, GM issued a Special Coverage (N182202780) for the brake vacuum pump issue in MY 2014-2017 trucks and 2015-2017 SUVs on the K2XX platform for 6 years or 72,000 miles. Special Coverage repair includes the replacement of the vacuum pump and vacuum pump belt. Consumers received notification of the coverage via mail. On September 6, 2019, GM notified NHTSA that it was conducting safety recall 19V-645 which reprograms the electronic brake control module (EBCM) and included approximately 3.5 million trucks and SUVs. In October 2019, GM extended the terms of special coverage N182202780 to 10 years or 150,000 miles as well as now including the entire scope of recall 19V-645. In October 2020, GM expanded the scope of coverage N182202780 to include the MY 2018 Escalade and 2019 Tahoe.The remedy implemented in GM recall 19V-645 appears to be sufficient in addressing the safety-related concerns of this issue. Loss of vacuum assist now occurs at a progressive rate as well as there being a more timely warning of a brake problem to the driver through the driver information center (DIC). In view of the recall action and revision to the special coverage, this Preliminary Evaluation is closed. The agency reserves the right to take additional action if warranted by new circumstances. The ODI reports cited above are available for review online at NHTSA.gov under the identification numbers in the attached document.

The contact owns a 2015 GMC Yukon Denali. The contact stated that while driving 80 MPH, the vehicle hesitated, and failed to accelerate as intended while depressing the accelerator pedal. In addition, there was an abnormal knocking sound coming from underneath the passenger’s side of the vehicle. The check engine warning light was illuminated. The contact arrived at the residence and used a personal diagnostic reader and retrieved information related to misfires in cylinder #2 and #4. The contact replaced the spark plugs and the ignition coils. The contact test drove the vehicle, and the check engine warning light later illuminated. The contact swapped the ignition coils; however, the failure persisted. The vehicle was taken to the dealer where it was diagnosed that Active Fuel Management (AFM) and Dynamic Fuel Management (DFM) had failed and caused the lifters to fail. The vehicle was not repaired due to the cost. The vehicle remained at the dealer unrepaired. The manufacturer was made aware of the failure but offered no assistance. The failure mileage was approximately 96,000.

NHTSA ID

11680375

Incident

Jul 23, 2025

Mileage

96,000 mi

The contact owns a 2015 GMC Yukon Denali. The contact stated that while driving at undisclosed speeds, the contact heard an abnormal grinding sound, and the transmission was shifting hard. While making a turn, there was an abnormal sound coming from the vehicle. There were unknown warning lights illuminated. The contact stated that the failure was related to NHTSA Campaign Number: 14V152000 (Power Train). The vehicle was taken to an independent mechanic, who informed the contact that the failure was due to the transmission. The local dealer was not contacted. The vehicle was not diagnosed or repaired. The manufacturer was contacted and referred the contact to the NHTSA Hotline for assistance. The failure mileage was approximately 100,000. The VIN was not available.

NHTSA ID

11622331

Incident

Jan 14, 2021

Mileage

100,000 mi

The contact owns a 2015 GMC Yukon Denali. The contact stated while driving at approximately 20 MPH, the vehicle started decelerating with a slight clunking sound coming from underneath the front passenger’s side of the vehicle. The vehicle then lost motive power. The contact coasted to the side of the road and turned off the vehicle. After waiting for a while, the vehicle was started and the contact became aware that the instrument panel and all other electrical systems were activated as expected; however, the engine failed to start. The vehicle was towed to the dealer where it was diagnosed that there was a failure with the engine. The vehicle had not been repaired. The vehicle was then towed to an independent mechanic where it was confirmed that the engine had failed, and the starter needed to be replaced. The starter had been replaced; however, while starting the vehicle the engine emitted a loud rumbling noise which the dealer described as rocks being tossed around. The contact stated that the engine needed to be replaced. The vehicle was not repaired. The manufacturer had not been made aware of the failure. The failure mileage was 150,150.

NHTSA ID

11612810

Incident

Sep 1, 2024

Mileage

150,150 mi

The contact owns a 2015 GMC Yukon Denali. The contact stated that while driving at an undisclosed speed, the transmission was inoperable. The contact stated that when the gear shifter was shifted into reverse, the vehicle would drive forward. The contact also stated that when the gear shifter was in neutral, the vehicle would reverse instead. The vehicle was driven to the residence. The contact stated that the transmission fluid had leaked onto the ground. The vehicle was towed to an independent mechanic where it was diagnosed with a failed transmission. The contact was informed that the transmission needed to be replaced. The manufacturer was made aware of the failure and advised the contact to report the failure to the NHTSA Hotline. The failure mileage was approximately 102,000.

NHTSA ID

11572365

Incident

Feb 15, 2024

Mileage

102,000 mi

The contact owns a 2015 GMC Yukon Denali. The contact stated that the fuel tank was leaking fuel. The contact had not taken the vehicle to a certified mechanic or dealer to be diagnosed or repaired. The manufacturer was not made of the failure. The approximate failure mileage was 130,000.

NHTSA ID

11476364

Incident

Jul 14, 2022

Mileage

130,000 mi

The contact owns a 2015 GMC Yukon Denali. The contact stated that while driving the air condition system was blowing hot air and then became inoperable. There were no warning lights illuminated. The vehicle was taken to the local dealer where it was diagnosed and determined that the A/C condenser and A/C control module needed to be repaired. The vehicle was not repaired. The manufacture was not notified of the failure. The approximate failure mileage was 75,000.

NHTSA ID

11462781

Incident

Jun 1, 2021

Mileage

75,000 mi

The contact owns a 2015 GMC Yukon Denali. The contact stated that while his mother was driving approximately 50 MPH, the brake service warning light illuminated and the vehicle started to decelerate as if the brakes were engaged. The contact's mother was able to pull over safely and turned the vehicle off and on and was able to continue driving to her destination. The brake failure persisted. The contact had not taken the vehicle to a local dealer. The vehicle was not diagnosed or repaired. The manufacturer had not been informed of the failure. The failure mileage was approximately 115,000.

NHTSA ID

11458720

Incident

Aug 13, 2018

Mileage

115,000 mi

TAIL LIGHTS SOMETIMES WORK AND MOST OF THE TIME DOES NOT WORK. I SEE HUNDREDS OF COMPLAINTS ABOUT THIS AND NOTHING IS BEING DONE ABOUT IT! THIS WILL BE MY FIRST AND LAST TIME BUYING A GMC CAR. THIS IS VERY DANGEROUS AND A VERY EXPENSIVE PROBLEM TO HAVE!

NHTSA ID

11302141

Incident

Aug 1, 2019

Mileage

60,000 mi

PI to help diagnose A/C concern

This preliminary information communicates information about how to determine if a wheel and tires size change is available.

This Preliminary information communicates the steps on how to save a GDS2 Session Log and upload to a Technical Assistance Case in CX Connect.

This preliminary information advises a dealer on how to email GDS2 session logs into Technical Assistance.

This preliminary information advises a dealer on how to email GDS2 session logs into Technical Assistance.

This Preliminary Information communication provides information to the technician about vehicles that have had multiple repair attempts that are being performed on customer’s vehicles that exhibit vibration conditions without utilizing the support of General Motors Technical Assistance Center. If valid vibration frequency or Road Force Variation data has been collected and a repair attempt does not correct the customer complaint, contact General Motors Technical Assistance Center for further support. For any vehicles that remains unrepaired after being at the dealer for three days or more and a related bulletin or PI is not found, contact General Motors Technical Assistance Center for further support.