Heating and Air Conditioning: Description and Operation

System Diagram (Part 1):

System Diagram (Part 2):

System Outline

The A/C amplifier receives various signals, I.E., the engine RPM from the engine control module and coolant temperature from the engine control module, etc.

When the engine is started and the A/C SW (A/C control assembly) is on, a signal is input to the A/C amplifier.

As a result, current flows from IG1 NO.2 fuse to TERMINAL 2 of the MG CLT relay to TERMINAL 1 to TERMINAL MGC of the A/C amplifier to GROUND, turning the MG CLT relay on, so that the magnetic clutch is on and the A/C compressor operates.

If the integration control and panel detects the following conditions, it stops the air conditioning:
- Evaporator outlet air temperature is too low.
- There is a marked difference between the compressor speed and the engine speed.
- The refrigerant pressure is abnormally high or abnormally low.
- The engine speed is too low.
- Rapid acceleration occurs.