THS II (TOYOTA HYBRID SYSTEM II)
TH-42
System Monitoring Control
The THS ECU constantly monitors the SOC (state of charge) of the HV battery. When the SOC is below
the lower level, the THS ECU increases the power output of the engine to operate MG1, which charges
the HV battery. When the engine is stopped, MG1 operates to start the engine, then the engine operates
MG1 to charge the HV battery.
If the SOC is low, or the temperature of the HV battery module, MG1 or MG2 is higher than the specified
value, the THS ECU restricts the motive force applied to the drive wheels until it is restored to the normal
value.
Shut Down Control
The MG1 and MG2 are shut down when the shift position is in the N position. This is because MG1 and
MG2 must be stopped electrically as a means of shutting down the motive force, since MG2 is mechanically
joined to the front wheels.
