Tracker 2WD L4-1.6L VIN 6 (2000)
Control Module HVAC: Description and Operation
Heating, Ventilation and Air Conditioning
A/C Compressor Control Module
The A/C compressor control module controls the operation of the compressor clutch in response to the signals that are received from the following
components:
^
The A/C ON/OFF switch
^
The A/C refrigerant pressure switch
^
The evaporator temperature sensor
^
The Powertrain Control Module (PCM)
The A/C compressor control module performs the following functions when the air conditioning system is operating:
^
Energizes the compressor clutch in response to the following conditions:
-
An A/C system ON request
-
The determination of favorable system conditions for A/C operation
^
De-energizes the compressor clutch in response to the following conditions:
-
A high refrigerant pressure signal from the refrigerant pressure switch
-
A low refrigerant pressure signal from the A/C refrigerant pressure switch
-
A low evaporator temperature signal from the evaporator temperature sensor
-
A high engine demand (WOT) signal from the PCM
-
An A/C system OFF request
-
An engine coolant temperature over 110°C (230°F)
A/C Idle-Up Signal
The A/C compressor control module provides an A/C idle-up signal to the Powertrain Control Module (PCM) when the A/C compressor clutch is in
operation. The PCM uses the A/C idle-up signal in order to modify the engine idle speed. The PCM will signal the Idle Air Control (IAC) valve to open
the air passage in the throttle body. Opening the IAC air passage slightly will increase the engine speed in order to prevent a rough idle or a stalling
condition.
