Monitor Description
WARNING: This page is about a different car, the 2008 Toyota Yaris. However, it is still accessible from the selected car via links, so may be relevant.
A certain time after the ignition switch is turned to OFF, the soak timer activates the ECM to begin system monitoring. While the engine is running, the ECM monitors the synchronization of the soak timer and the CPU clock. If these two are hot synchronized, the ECM interprets this as a malfunction, illuminates the MIL and sets this DTC (2 trip detection logic).