Land Cruiser URJ200 URJ202 GRJ200 VDJ200 HEATING / AIR CONDITIONING

Land Cruiser URJ200 URJ202 GRJ200 VDJ200 HEATING / AIR CONDITIONING

Start the engine.

Check the sight glass on the liquid pipe A.

Test conditions:

The back-up power source circuit for the air conditioning amplifier assembly is shown below. Power is supplied even after the ignition switch is turned off and is used for diagnostic trouble code memory, etc.

The main power source is supplied to the air conditioning amplifier assembly when the ignition switch is turned to ON. The power source is used for operating the air conditioning amplifier assembly, servo motors, etc.

PTC heater relays are closed in accordance with signals from the air conditioning amplifier assembly and power is supplied to the quick heater assembly installed on the radiator heater unit.

The blower with fan motor sub-assembly operates according to signals from the air conditioning amplifier assembly. The blower with fan motor sub-assembly speed signals are transmitted by changes in the duty ratio.

Duty Ratio:

The duty ratio is the ratio of the blower with fan motor sub-assembly on time (T1) to the total of the blower with fan motor sub-assembly on and off time (T2).

This circuit consists of the air conditioning control assembly and air conditioning amplifier assembly. When the air conditioning control assembly is operated, signals are transmitted to the air conditioning amplifier assembly through the LIN communication system.

If the LIN communication system malfunctions, the air conditioning amplifier assembly does not operate when the air conditioning control assembly is operated.

The No. 1 air conditioning radiator damper servo sub-assembly (mode damper servo) sends pulse signals to inform the air conditioning amplifier assembly of the damper position. The air conditioning amplifier assembly activates the motor (normal or reverse) based on the signals to move the air outlet damper to any position, which controls the air outlet changes.