You can read the bill and see the number of co-sponsors, by clicking this bill link: S. 2232.
One result of a failure to audit the Fed is a swirl of questions about who "owns" the Fed. Although member banks technically "own" regional Federal Reserve banks, the value of the shares never changes and dividends are fixed by law, with all extra profits going into the U.S. Treasury. In addition, the banks are dominated by the Fed's politically-appointed Board of Governors, who have fixed salaries. It's a simple fact: The Federal Reserve Board is the government and it dominates the Federal Reserve System for the government's ends, not for the interests of private investors... Bill Woolsey explains it here.
The current law determining the limits of the Comptroller General's ability to audit the Fed is TITLE 31 > SUBTITLE I > CHAPTER 7 > SUBCHAPTER II > § 714.
The relevant section:
(b) Under regulations of the Comptroller General, the Comptroller General shall audit an agency, but may carry out an onsite examination of an open insured bank or bank holding company only if the appropriate agency has consented in writing. Audits of the Federal Reserve Board and Federal reserve banks may not include:
(1) transactions for or with a foreign central bank, government of a foreign country, or nonprivate international financing organization;
(2) deliberations, decisions, or actions on monetary policy matters, including discount window operations, reserves of member banks, securities credit, interest on deposits, and open market operations;
(3) transactions made under the direction of the Federal Open Market Committee; or
(4) a part of a discussion or communication among or between members of the Board of Governors and officers and employees of the Federal Reserve System related to clauses (1)-(3) of this subsection.
An explanation of the Federal Reserve's Open Market Operations is described by the Fed itself on its website.
We provide the first few words of the letter so that Congressional offices will see the most important point right at the start, and so that no one can hijack our system for another purpose. Here's the part we provide . . .