This RQ investigation was opened to collect and analyze additional information to better evaluate the scope and timeliness of Honda's two safety recalls addressing rupturing of the driver's side air bag inflators (08V-593 and 09V-259).In an earlier response to RMD's request for information, Honda indicated that the second recall (09V-259), essentially an expansion of the first (08V-593), was necessary since later information informed that the source of the defect was different than originally postulated, and so the scope of the vehicles affected changed. Honda indicated that it had relied on its supplier of the air bag inflators, Takata, Inc. (Takata), in studying the possible sources of the inflator ruptures and identifying the recall populations.Accordingly, RMD issued a request forinformation to Takata on November 20, 2009, and Takata provided a partial response on December 23, 2009.Takata then provided its complete response on February 19, 2010.Takata informed ODI that, after analysis of several ruptured inflators, Takata and Honda initially attributed the defect to handling of the propellant during inflator assembly that could have yielded increased moisture levels that, when coupled with thermal cycling in automobiles over time, could lead to reduced propellant density and overly aggressive combustion during air bag deployment.However, it discovered upon review of inflators returned from the 08V-593 recall campaign, some of which fell outside the manufacturing range when Takata suspected the propellant was exposed to elevated moisture, that the source of the defect was more likely due to problems with a specific compression press (Stokes press) used to form the inflator's propellant.Specifically, the propellant tablets produced by the press were found to be less dense, and therefore more susceptible to overly aggressive combustion during air bag deployment.Takata identified the manufacturing time frame over which the tablets were shown to have less dense properties as the end of calendar year 2000. Takata informed Honda of its discovery on or about June 12, 2009.Honda made its defect decision and then notified NHTSA of it on June 30, 2009.Honda then supplemented its filing with an identification of the specific vehicles to be included in the campaign, as well as identifying additional models to be included, on July 29, 2009.As with the 08V-593 campaign, Takata examined inflators returned from the 09V-259 campaign, and some of which were manufactured outside of the range when the Stokes press was found to have produced less dense propellant (beyond the end of February 2001).It provided those findings to Honda and Honda decided to expand safety recall 09V-259 to include all vehicles with inflators containing propellant manufactured using the Stokes press.Honda notified NHTSA of its decision on February 9, 2010.Based upon all available information, there is insufficient information to suggest that Honda failed to make timely defect decisions on information it was provided.Also, given that all inflators with propellant manufactured using the Stokes press have been recalled, there are no additional vehicles to be investigated and campaigned.Accordingly, this RQ is closed.