The Office of Defects Investigation (ODI) has completed its review of a defect petition received on 14 August 2019 requesting an investigation of an alleged defect of the manual transmissions in Model Year (MY) 2019 Volkswagen (VW) GTI, Golf GTI and Jetta GLI vehicles. The stalling incidents cited occurred without warning as the vehicle slows to a stop or prepares to make a turn across traffic with the clutch pressed in and the vehicle in neutral.The hazard posed by a vehicle stalling event is manifested in the inability of the vehicle to move with the flow of surrounding traffic. Two factors have a major impact on the potential hazard to the vehicle, its occupants and surrounding vehicles: the surrounding traffic speed and the subject vehicle's restart ability. In the case of the vehicles that are the subject of this petition, restart is immediate and the stalls occur when the vehicle is slowing to stop for a traffic signal, making a turn, or is completely stopped. These circumstances substantially reduce the risk of harm to the vehicle, its occupants and surrounding vehicles.As of March 2, 2020, out of the population of 11,333 subject vehicles, NHTSA has identified 214 consumer complaints in its database, with unique Vehicle Identification Numbers (VIN), citing engine stalling as vehicles are being brought to a stop and/or preparing to make a cross traffic turn. When combined with the warranty, field report and customer complaint data received from VW in response to the Information Request letter sent, NHTSA identified 413 unique VINs alleging low speed engine stalling.Volkswagen determined that the low speed / idle engine stall was the result of unwanted gases remaining in the cylinder caused by the intake valve camshaft not being in the correct position at idle. The intake camshaft is in an advanced position. This advanced position results in too much overlap with the position of the exhaust valve camshaft, allowing both the intake and exhaust valves to be open at the same time. The erroneous advanced position of the intake camshaft is a result of low oil pressure at idle and high oil temperatures, greater than or equal to 110"C/230"F combined with engine control algorithms in the Engine Control Module (ECM) that position the intake camshaft. Based on examination of returned engines, only engines manufactured at the Silao Mexico plant were affected due to a tolerance stack-up issue with the oil system of the engines.In December of 2019, VW initiated a Service Action (24FD) to remedy the stalling issue in the affected vehicles. The warranty for the affected vehicles was extended to December 31, 2025. The software in the Engine Control Module (ECM) will be updated with a new calibration value for the adaptation nodes of the regulation valve. This is a directed action with letters being sent to vehicle owners asking them to bring their vehicles to their dealership to have the software update installed in their vehicle. The letters were sent in December 2019.After thoroughly assessing the material submitted by the petitioner, information already in NHTSA's possession, information submitted by Volkswagen in response to an information request and the potential risks to safety implicated by the petitioner's allegation, NHTSA does not believe that the stalling condition as alleged by the petitioner indicates the likelihood of a safety related defect that would warrant a formal investigation, therefore the petition is denied. Further specifics can be found in the Federal Register Notice.ODI complaint ID Numbers are listed on the attached sheet.
