On June 3, 2013, the SEC filed a civil action against PACCAR Inc. and its wholly owned subsidiary PACCAR Financial Corp. for internal accounting deficiencies. The SEC complaint stated that: "This case concerns financial reporting, books and records, and internal controls violations by PACCAR Inc. ('PACCAR' or the 'Company'), a commercial truck manufacturer based in Bellevue, Washington, and its wholly-owned subsidiary, PACCAR Financial Corp.... The accounting deficiencies stem from three separate and distinct issues. First, from 2008 through the third quarter of 2012, PACCAR failed to report the operating results for its parts business as a reportable segment, as required by Generally Accepted Accounting Principles (GAAP). Because PACCAR failed to report its parts business as a separate segment, its financial reports did not contain certain information about its parts business separate and apart from the truck business, and accordingly readers of its reports may not have been able to understand PACCAR's business as seen by the Company's executives.... Second, during 2009 PACCAR and PFC failed to maintain accurate books and records regarding their impaired loans and leases. As a result, PACCAR's and PFC's disclosures of impaired receivables and the specific reserves associated with these receivables in the notes to the financial statements filed with SEC Form 10-K filings were understated.... Third, PACCAR made overstatements in equal and offsetting amounts to loan and lease originations and collections for two foreign subsidiaries in its statement of cash flows for two quarters in 2009."

On June 3, 2013, the SEC published a litigation release regarding its civil action against PACCAR and its subsidiary PACCAR Financial Corp. According to the SEC, PACCAR and its subsidiary PACCAR Financial Corp. agreed to settle the SEC's charges. Subject to the court's approval, PACCAR agreed to the entry of a permanent injunction from its violation of Sections 13(a), 13(b)(2)(A) and 13(b)(2)(B) of the Exchange Act, and to pay a $225,000 penalty.

On July 18, 2013, Federal District Judge John C. Coughenour entered final judgment against PACCAR Financial Corp. pursuant to the SEC and PACCAR Financial Corp.'s consent.