A/C-ECU

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 17.0 °C (MAX COOL) or at 27.0 °C (MAX HOT) 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 cancelled because of the customise function, the automatic control is not performed.

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 improve 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.

note

When abnormality occurs, the A/C indicator flashes.

REAR WINDOW DEFOGGER TIMER CONTROL

In order to prevent battery consumption, the defogger is automatically turned OFF, 20 minutes after it is turned ON.

PROTECTION CONTROL AT AIR BAG DEPLOYMENT (DURING COLLISION)

When the air bag deployment is detected, the A/C system is stopped to prevent the secondary troubles (including damages due to the falling of motors).

CUSTOMISE FUNCTION

Depending on the user’s preference, the following functions can be adjusted. The programmed information is held even when the battery is disconnected.

Automatic control for inside/outside air selection
Press and hold (approximately for 10 seconds) the inside/outside air selection switch to cancel the automatic control for inside/outside air selection.
A/C automatic control
Press and hold (approximately for 10 seconds) the A/C switch to cancel the A/C automatic control.

COMMUNICATION

A/C-ECU performs the signal transmission and reception with each ECU via CAN (Controller Area Network)*¹. Also, with the heater control panel, it transmits and receives signals via serial communication.

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.

DIAGNOSTIC FUNCTION
Service data output
Actuator test

note

For each item, refer to the Workshop Manual.