Is sleep mode basically dumb vehicle mode with basic alarm features?It's normal.
The system works two ways:
- Battery depletion. At a given State of Charge (SoC), the car will begin shedding load and go to sleep, to protect the battery. The objective is to have at least enough power to start the car
- Time. Even if the battery is at an optimum SoC, the car doesn't know when someone will start it again. The car goes to sleep
I keep a tender on throughout Winter. The car goes to sleep about the two-week mark.
The Oil Life Monitor works in a similar manner: the Powertrain Control Module considers both time and engine operation.
The time variable is a catch-all to either function.