2014 GMC Sierra 1500 Recalls

From 2000 through 2017, Takata produced millions of air bag inflators using two types of phase-stabilized ammonium nitrate ("PSAN") propellant -- propellant 2004 and propellant 2004L. After prolonged exposure to high temperature cycles and humidity, inflators using propellant 2004 can degrade, causing the propellant to burn too quickly when ignited. The rapid burning can cause the inflator to rupture during deployment, potentially causing serious or even fatal injury to vehicle occupants. See 2016 Blomquist Report at www.nhtsa.gov/sites/nhtsa.gov/files/documents/expert_report-hrblomquist.pdf.Consequently, all frontal inflators using propellant 2004 that do not contain a "desiccant" (a substance that traps and holds moisture) in US vehicles are under recall. These "non-desiccated" inflators either have been or are required to be replaced.In some cases, the remedy part for these recalled inflators was, or will be, an inflator using either propellant 2004 or 2004L that does contain a desiccant. None of these "desiccated" remedy parts (which were installed in older model year vehicles) are currently under recall for a degradation concern. Certain subsets of desiccated PSAN inflators using propellant 2004 for use as original equipment, however, have been recalled for a degradation concern. All Takata inflators produced with propellant 2004L contain desiccant, and none of these desiccated inflators using propellant 2004L are under recall for a degradation concern. There have been no reported field ruptures in any non-recalled desiccated PSAN inflators.It is understood that desiccants fully saturate at some threshold, at which point any additional moisture will not be captured. This means the degradation process observed in non-desiccated inflators using propellant 2004 may also occur in non-recalled desiccated inflators using propellant 2004, assuming additional moisture enters the inflator and high temperature cycling occurs. Based on available information, desiccant saturation can occur within the first five years in the worst environments, and the time required for full saturation is affected by multiple factors. While no present safety risk has been identified, further work is needed to evaluate the future risk of non-recalled desiccated inflators using propellant 2004.Three entities -- Takata (now known as TK Global), the Independent Testing Coalition, and Exponent -- have been studying the long-term behavior of Takata desiccated PSAN inflators using propellant 2004L (as well as 2004) in the presence of moisture and temperature cycling. The research efforts, which include development of predictive modeling techniques and field sample analysis, are ongoing. To date, none of the researchers have identified field evidence showing that propellant 2004L is undergoing a degradation process that leads to aggressive deployment and potential rupture. However, the time in service of such inflators remains short compared to that of the inflators using propellant 2004. Further study is needed to assess the long-term safety of desiccated inflators using propellant 2004L.The Office of Defects Investigation is opening this investigation to examine whether a safety defect related to propellant degradation exists in non-recalled desiccated PSAN frontal inflators manufactured by Takata. This investigation will require extensive information on Takata production processes and surveys of inflators in the field. Lists of recall actions that may have used desiccated PSAN inflators as remedy parts, as well as the makes and models originally manufactured with them, is available with the downloadable version of this document (see nhtsa.gov/recalls?nhtsaId=EA21002 -- note this information is subject to change/revision as the investigation proceeds). This investigation does not supersede EA15-001, which remains open.

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.