Michael Barr

March 30, 2011

Despite the redactions, we can still learn some interesting facts about Toyota’s embedded software and NASA’s technical review of the same.

Last month, the National Highway Traffic Safety Administration (NHTSA) and the NASA Engineering and Safety Center (NESC) published reports of their joint investigation into the causes of unintended acceleration in Toyota vehicles. NASA’s multidisciplinary NESC technical team was asked, by Congress, to assist NHTSA by performing a review of Toyota’s electronic throttle control and the associated embedded software. In a carefully-worded concluding statement, NASA stated that it “found no electronic flaws in Toyota vehicles capable of producing the large throttle openings required to create dangerous high-speed unintended acceleration incidents.” (The official reports and a number of supporting files are available for download at www.nhtsa.gov/UA.)

The first thing you will notice if you join me in trying to judge the technical issues for yourself are the redactions: pages and pages of them. In parts and entirely for unexplained reasons, this report on automotive electronics reads like the public version of a CIA training manual. I’ve observed that approximately 193 of the 1,061 pages released so far feature some level of redaction (via black boxes, which obscure from a single number, word, or phrase to a full table, page, or section). The redactions are at their worst in NASA’s Appendix A, which describes NASA’s review of Toyota’s embedded software in detail.1 More than half of all the pages with redactions (including the vast majority of fully redacted tables, pages, and sections) are in that Appendix.