AIR CONDITIONER CONTROL SYSTEM



General


The air conditioner system with following features has been adopted.


CONTROL



FORCED DEF CONTROL


When air outlet position is switched to DEF, A/C is automatically turned ON, and outside/inside air selection damper is set to the fresh air position to quickly defrost the windshield screen.

MAX COOL, MAX HOT CONTROL


When the set temperature is at MAX COOL (15°C) or at MAX HOT (29°C) with the air outlet and air volume at the AUTO positions, the following controls are made automatically by the A/C-ECU.
Subject to control
MAX COOL
MAX HOT
Air mix damper
MAX COOL position
MAX HOT position
Air outlet mode
FACE position
FOOT position
Air volume
Maximum
Maximum
Outside/inside air selection damper
Air recirculation position*
Fresh air position*
Air conditioner switch
ON*
OFF*
note "*" indicates that when the automatic control is not cancelled using the customise function, the manual operation is disabled.

IDLE-UP CONTROL


A/C-ECU and the engine-ECU communicate with each other through the CAN communication. The idle-up speed of the engine is controlled in two steps depending on the A/C load to secure the air cooling performance during summer and to enhance fuel economy in seasons with moderate temperature.

DETECTION CONTROL FOR REFRIGERANT LEAKS


A/C-ECU determines if the refrigerant amount is less than specified or refrigerant pressure is abnormal by using the ambient temperature (ambient temperature sensor to measure refrigerant inflation rate) and refrigerant pressure (measured by the A/C pressure sensor). When refrigerant amount or refrigerant pressure is judged abnormal, the compressor is cut-off to protect the A/C system.

PROTECTION CONTROL AT AIR BAG DEPLOYMENT (DURING COLLISION)


When the air bag deployment is detected, the A/C system is stopped.

COMMUNICATION


A/C-ECU performs the signal transmission and reception with each ECU via CAN (Controller Area Network)*.
note *: For details of CAN communication, refer to GROUP 54C - Controller Area Network .

DIAGNOSTIC FUNCTION


A/C-ECU has the following functions for easier system checks.

note For each item, refer to the Workshop Manual.