Toyota Prius 2010 Repair Manual page 36

10. COMPRESSOR WITH MOTOR ASSEMBLY
(a) Compressor Control
HINT:
In order to ensure the proper insulation of the internal high-voltage portion of the compressor and the
compressor housing, this vehicle has adopted compressor oil (ND11) with a high level of insulation
performance. Therefore, never use compressor oil other than the ND11 type compressor oil or its equivalent.
(1) The A/C amplifier calculates the target compressor speed based on the target evaporator temperature
(calculated from the temperature control switch, room temperature sensor, ambient temperature sensor, and
solar sensor) and the actual evaporator temperature detected by the evaporator temperature sensor. Then, the
A/C amplifier transmits the target speed to the power management control ECU. The power management
control ECU controls the A/C inverter based on the target speed data in order to control the compressor with
motor assembly to a speed that suits the operating condition of the air conditioning system.
(2) The A/C amplifier calculates the target evaporator temperature, which includes corrections based on the
temperature control switch, room temperature sensor, ambient temperature sensor, automatic light control
sensor, and evaporator temperature sensor. Accordingly, the A/C amplifier controls the compressor speed to an
extent that does not inhibit the proper cooling performance or defogging performance.
(3) The compressor with motor assembly uses high-voltage alternating current. If a short or open circuit occurs
in the compressor with motor assembly wiring harness, the power management control ECU will cut off the
A/C inverter circuit in order to stop the power supply to the compressor motor.
11. PTC HEATER (w/ PTC Heater Assembly)
(a) General
(1) The PTC heater assembly is located above the heater core in the air conditioning unit.
(2) The PTC heater assembly consists of a PTC element, aluminum fin, and brass plate. When current is applied
to the PTC element, it generates heat to warm the air that passes through the unit.
2010 Toyota Prius Repair Manual