DTC P2610: ECM/PCM Internal Engine Off Timer Performance: Description
The soak timer is built into the ECM. To ensure that the Evaporative Emission (EVAP) monitor values will be accurate, the soak timer counts 5 hours (+-15 minutes) from when the ignition switch is turned OFF. This allows the fuel to cool down, which stabilizes the Fuel Tank Pressure (FTP). When approximately 5 hours have passed, the ECM turns ON.