Is fraudulent concealment a threshold matter for the purposes of the statute of limitations?

The second "threshold matter" set forth in Fobbs is the point at which we diverged from the state's doctrine. California has long refused to apply the equitable tolling doctrine to toll the statute of limitations on a claim for a distinct wrong that was not the basis of the earlier proceeding. For example, in Aero jet General Corporation v. Superior Court , 177 Cal. App. 3d 950 (1986), one of the plaintiffs received workers' compensation benefits for an injury and then filed a lawsuit not only for personal injury, but for fraudulent concealment. The court declined to toll the limitations period on the fraudulent concealment cause of action because it involved a wrong distinctly different from plaintiff's workplace injury (for which workers' compensation was the exclusive remedy in any event). The court reasonably concluded that filing the workers' compensation claim did not notify defendants of the nature "or the imminence" of the fraudulent concealment cause of action, and on that basis, declined to toll the statute of limitations.