6 air conditioning ecu the following table is a

6. Air Conditioning ECU
The following table is a comparison of the air conditioning ECU functions between the new and previous
model.
System Function New Previous
Calculation of
Required Outlet Air
Temperature
Calculates the required outlet air temperature based on
the set temperature, room air temperature, ambient air
temperature and solar radiation.
Temperature Control
To drive the air mix servomotor in accordance with the
required outlet air temperature, the air temperature
passed through the evaporator and the engine coolant
temperature and to control the outlet air temperature
(Air Mix Damper Control).
Sets the blower speed according to operation of the
blower switch (Manual Control). (5-step)
(5-step)
Blower Control
When the automatic control or front defroster switch is
turned on, the blower starts. Then the blower speed
that is appropriate for the required outlet air
temperature
is compared with the blower speed that is appropriate
for solar radiation, and the blower is controlled with the
faster speed of the above two speeds (Automatic
Control). However, when the coolant temperature is
below a predetermined level and the air outlet is in the
“foot” or “bi-level” mode, the blower will not operate
(Warm-Up Control).

100 BODY ELECTRICAL — AIR CONDITIONING
System Function New Previous
Blower Control
When the air outlet mode is at “face” or “bi-level” and
the required outlet air temperature is below a
predetermined level, the blower is set to operate after a
time lag in order to prevent hot air from being blown
out suddenly right after the engine is started
(Time-Lagged Air Flow Control).
Drives the air inlet servomotor according to the
operation of the air inlet control switch and fixes the
dampers in the “fresh” or “recirc.” position (Manual
Control).
Air inlet Control
Switches the damper position between “fresh”, “fresh
and recirc. mix” or “recirc.” according to the required
outlet air temperature (Automatic Control).
Fixes the damper position on “fresh” if the front
defroster switch is turned on during automatic control
(Forced Fresh Air Intake Control).
Drives the air outlet step motor in accordance with the
operation of the mode select and front defroster
switches and fixes the dampers in the “face”, “bi-level”,
“foot”, “foot and def.” or “def.” position (Manual
Control).
Air Outlet Control
Switches the damper position between “face”,
“bi-level” of “foot” according to the required outlet air
temperature (Automatic Control)
If the blower is under warm-up control when the air
outlet mode is in “bi-level” or “foot” mode, the LCD
display remains as it is while the air outlet step motor is
driven and the dampers are switched to the “def.”
position, preventing cool air from leaking from the foot
vent (Def.-Foot Control).

101 BODY ELECTRICAL — AIR CONDITIONING
System Function New Previous
If the A/C switch is switched on while the blower is
turned on, this turns on the magnetic clutch relay and
operates the compressor (Manual Control).