SYSTEM DESCRIPTION
- Automatic air conditioning system is controlled by each function of A/C auto amp., ECM, IPDM E/R and BCM.
DESCRIPTION
- A/C auto amp. changes duty ratio of blower motor drive signal and controls air flow continuously. When air flow is increased, duty ratio of blower motor control signal gradually increases to prevent a sudden increase in air flow.
- In addition to manual control and automatic control, air flow control consists of starting fan speed control, low coolant temperature starting control, high in-vehicle temperature starting control and fan speed control at door motor operation
Scheme 52
- A/C auto amp. decides target air flow depending on target air mix door opening angle.
- A/C auto amp. changes duty ratio of blower motor control signal and controls the air flow continuously so that air flow matches the target air flow.
- When air outlet is VENT or B/L, the minimum air flow is changed depending on sunload.
Scheme 53
- When blower motor is activated, A/C auto amp. gradually increases duty ratio of blower motor control signal to prevent a sudden increase in discharge air flow.
- It takes approximately 8 seconds for air flow to reach HI from LOW.
FAN SPEED CONTROL AT DOOR MOTOR OPERATION
When mode door motor is activated while air flow is more than the specified value, A/C auto amp. reduces fan speed temporarily so that mode door moves smoothly.
- When the compressor activation condition is satisfied while blower motor is activated, A/C auto amp. transmits A/C ON signal and blower fan ON signal to BCM.
- BCM transmits the A/C ON signal and blower fan ON signal to the ECM via CAN communication line.
- ECM judges that the compressor can be activated depending on the state of each sensor (refrigerant pressure sensor signal and others) and transmits A/C compressor request signal to IPDM E/R via CAN communication.
- IPDM E/R turns A/C relay ON and activates the compressor depending on request from ECM.
- The step motor system is adopted for air mix door motor (driver side).
- When a drive signal is input from A/C auto amp. to door motor, a step motor built into the door motor rotates according to the drive signal, and then stops at the target door position.
- Rotation of motor is transmitted to air mix door (driver side) [upper air mix door (driver side) and lower air mix door (driver side)] by link, rod and lever, then air flow temperature (driver side) is switched.
Scheme 54
- The 4 drive coils are excited in sequence in order to drive the motor.
- Direction of rotation is changeable by recomposing pattern of excitation.
- The step motor system is adopted for air mix door motor (passenger side).
- When a drive signal is input from A/C auto amp. to door motor, a step motor built into the door motor rotates according to the drive signal, and then stops at the target door position.
- Rotation of motor is transmitted to air mix door (passenger side) [upper air mix door (passenger side) and lower air mix door (passenger side)] by link, rod and lever, then air flow temperature (passenger side) is switched.
Scheme 55
- The 4 drive coils are excited in sequence in order to drive the motor.
- Direction of rotation is changeable by recomposing pattern of excitation.
- The step motor system is adopted for mode door motor.
- When a drive signal is input from A/C auto amp. to door motor, a step motor built into the door motor rotates according to the drive signal, and then stops at the target door position.
- Rotation of motor is transmitted to mode door (center ventilator and defroster door, sub defroster door, side ventilator door, and foot door) by link, rod, and lever, then air outlet is switched.
Scheme 56
- The 4 drive coils are excited in sequence in order to drive the motor.
- Direction of rotation is changeable by recomposing pattern of excitation.
- The step motor system is adopted for intake door motor.
- When a drive signal is input from A/C auto amp. to door motor, a step motor built into the door motor rotates according to the drive signal, and then stops at the target door position.
- Rotation of motor is transmitted to intake door, then air flow is switched.
Switch Operation
| Switch name | Function |
|---|---|
| Temperature control dial (Driver side) | Setting temperature is selected using this dial within a range between 18°C (60°F) and 32°C (90°F) at a rate of 0.5°C (1.0°F) per adjustment. NOTE: When air conditioning system is OFF, setting temperature can be selected only while air conditioning system status screen [only when MODE switch (driver side) is pressed] is indicated on display. |
| ON.OFF switch | Air conditioning turns ON <==> OFF each time this switch is pressed. When this switch is pressed while air conditioning is ON Air conditioning turns OFF and becomes the following status, when this switch is pressed. Air outlet: FOOT Air flow: OFF Air inlet: Settings set before this switch is pressed A/C switch: OFF When this switch is pressed while air conditioning is OFF Air conditioning turns ON and operates according to the settings set before air conditioning is turned OFF, when this switch is pressed. |
| AUTO switch | AUTO switch indicator turns ON and air conditioning becomes the following status, when this switch is pressed while air conditioning is ON. Air outlet: Automatic control Air flow: Automatic control Air inlet: Settings set before this switch is pressed A/C switch: ON Air conditioning turns ON and operates according to the following status, when this switch is pressed while air conditioning is OFF. (AUTO switch indicator turns ON) Air outlet: Automatic control Air flow: Automatic control Air inlet: Settings set before this switch is pressed A/C switch: ON NOTE: When air outlet or air flow is manually operated while AUTO switch indicator is ON, AUTO switch indicator turns OFF. However, automatic control continues for other functions than air outlet or air flow. |
| Fan switch | Air flow can be set within a range between 1st - 7th speed according to switch operation. Press +: Air flow increases Press -: Air flow decreases Air conditioning turns ON and operates according to the following status, when this switch is pressed while air conditioning is OFF. Air outlet: Automatic control Air flow: 1st speed Air inlet: Settings set before this switch is pressed A/C switch: Settings set before air conditioning is turned OFF NOTE: Automatic air flow control is cancelled (AUTO switch indicator turns OFF), when fan switch is pressed while AUTO switch indicator is ON. |
| A/C switch | Compressor control (switch indicator) changes between ON <==> OFF each time this switch is pressed while blower motor is operated. NOTE: A/C switch cannot be turned ON when blower motor is OFF. |
| DUAL switch | Left and right ventilation temperature separately control (switch indicator) changes between ON <==> OFF each time this switch is pressed while blower motor is operated. NOTE: Setting temperature for passenger side is the same as that for driver side when left and right ventilation temperature separately control is OFF. DUAL switch operation is not accepted when DEF mode is ON. |
| Temperature control dial (Passenger side) | Outlet air flow temperature of passenger side can be changed without changing outlet air flow temperature of driver side. Setting temperature is selected using this dial within a range between 18°C (60°F) and 32°C (90°F) at a rate of 0.5°C (1.0°F) per adjustment. NOTE: When air conditioning system is OFF, setting temperature can be selected only while air conditioning system status screen [only when MODE switch (passenger side) is pressed] is indicated on display. When DEF mode is ON, temperature control dial (passenger side) is inoperative. |
| REC switch | Switch indicator turns ON and air inlet is set to recirculation (REC), when this switch is pressed. NOTE: Air inlet can be changed when air conditioning is in OFF status. |
| FRE switch | Switch indicator turns ON and air inlet is set to fresh air intake (FRE), when this switch is pressed. NOTE: Air inlet can be changed when air conditioning is in OFF status. |
| MODE switch | Air outlet changes from VENT==> B/L ==> FOOT ==> D/F ==> VENT each time this switch is pressed. NOTE: Air outlet can be changed when air conditioning is in OFF status. Automatic air outlet control is cancelled (AUTO switch indicator turns OFF), when MODE switch is pressed while AUTO switch indicator is ON. |
| DEF switch | DEF mode (switch indicator) changes between ON <==> OFF each time switch is pressed. When this switch is pressed while air conditioning is ON Air conditioning becomes the following status when DEF mode is turned ON. Air outlet: DEF Air flow: Settings set before DEF mode is turned ON Air inlet: Fresh air intake A/C switch: ON Air conditioning becomes the following status when DEF mode is turned OFF. Air outlet: Settings set before DEF mode is turned ON Air flow: Settings set before DEF mode is turned OFF Air inlet: Settings set before DEF mode is turned OFF A/C switch: Settings set before DEF mode is turned OFF When this switch is pressed while air conditioning is OFF Air conditioning turns ON and operates in the following status, when DEF mode is turned ON. Air outlet: DEF Air flow: Automatic control Air inlet: Fresh air intake A/C switch: ON Air conditioning becomes the following status when DEF mode is turned OFF. Air outlet: Automatic control Air flow: Settings set before DEF mode is turned OFF Air inlet: Settings set before DEF mode is turned OFF A/C switch: Settings set before DEF mode is turned OFF NOTE: When DEF mode is turned ON while AUTO switch indicator is turned ON, AUTO switch indicator turns OFF. However, automatic air flow control continues. |
| NOTE |
|---|
| When air conditioning system is OFF, setting temperature can be selected only while air conditioning system status screen [only when MODE switch (driver side) is pressed] is indicated on display. |
| NOTE |
|---|
| When air outlet or air flow is manually operated while AUTO switch indicator is ON, AUTO switch indicator turns OFF. However, automatic control continues for other functions than air outlet or air flow. |
| NOTE |
|---|
| Automatic air flow control is cancelled (AUTO switch indicator turns OFF), when fan switch is pressed while AUTO switch indicator is ON. |
| NOTE |
|---|
| A/C switch cannot be turned ON when blower motor is OFF. |
| NOTE |
|---|
| Setting temperature for passenger side is the same as that for driver side when left and right ventilation temperature separately control is OFF. DUAL switch operation is not accepted when DEF mode is ON. |
| NOTE |
|---|
| When air conditioning system is OFF, setting temperature can be selected only while air conditioning system status screen [only when MODE switch (passenger side) is pressed] is indicated on display. When DEF mode is ON, temperature control dial (passenger side) is inoperative. |
| NOTE |
|---|
| Air inlet can be changed when air conditioning is in OFF status. |
| NOTE |
|---|
| Air inlet can be changed when air conditioning is in OFF status. |
| NOTE |
|---|
| Air outlet can be changed when air conditioning is in OFF status. Automatic air outlet control is cancelled (AUTO switch indicator turns OFF), when MODE switch is pressed while AUTO switch indicator is ON. |
| NOTE |
|---|
| When DEF mode is turned ON while AUTO switch indicator is turned ON, AUTO switch indicator turns OFF. However, automatic air flow control continues. |
Air conditioning system performs self-diagnosis, operation check, function diagnosis, and various settings using diagnosis function of each control unit.
| ECU | Diagnostic item (CONSULT) | |
|---|---|---|
| A/C auto amp. | HVAC | Self Diagnostic Result |
| Data Monitor | ||
| Active Test | ||
| Work support | ||
| BCM | BCM-AIR CONDITIONER | Self Diagnostic Result |
| Data Monitor | ||
| ECM | ENGINE | Self Diagnostic Result |
| Data Monitor | ||
| IPDM E/R | IPDM E/R | Self Diagnostic Result |
| Data Monitor | ||
ECU IDENTIFICATION
The IPDM E/R part number is displayed.
The purpose of the operational check is to check that the individual system operates normally.
Conditions: Engine running at normal operating temperature
If the temperature felt by the customer is different than the airflow temperature controlled by the temperature setting, the auto amplifier control temperature can be adjusted to compensate for the temperature setting.
In FOOT mode, the air blowing to DEF can change ON/OFF.
- If the ignition switch is turned to the OFF position while the FRE ( ) switch is set to ON (fresh air intake), "Perform the memory" or "Do not perform the memory" of the FRE ( ) switch ON (fresh air intake) condition can be selected.
- If "Perform the memory" was set, the FRE ( ) switch will be ON (fresh air intake) when turning the ignition switch to the ON position again.
- If "Do not perform the memory" was set, the air inlets will be controlled automatically when turning the ignition switch to the ON position again.
- If the ignition switch is turned to the OFF position while the REC ( ) switch is set to ON (recirculation), "Perform the memory" or "Do not perform the memory" of the REC ( ) switch ON (recirculation) condition can be selected.
- If "Perform the memory" was set, the REC ( ) switch will be ON (recirculation) when turning the ignition switch to the ON position again.
- If "Do not perform the memory" was set, the air inlets will be controlled automatically when turning the ignition switch to the ON position again.
Set the target evaporator temperature upper limit.
- Reset signal is transmitted from A/C auto amp. to air mix door motor, intake door motor and mode door motor. Starting position reset can be performed. NOTE: During reset, DEF switch indicator blinks.
- When air mix door motor, intake door motor or mode door motor is removed and installed, always perform door motor starting position reset.
CAN (Controller Area Network) is a serial communication system for real time application. It is an on-vehicle multiplex communication system with high data communication speed and excellent error detection ability. Many electronic control units are equipped onto vehicles, and each control unit shares information and links with other control units during operation (not independent). In CAN communication, control units are connected with two communication lines (CAN-H line, CAN-L line) allowing a high rate of information transmission with less wiring. Each control unit transmits/receives data but selectively reads required data only. Refer to " CAN COMMUNICATION SYSTEM: CAN COMMUNICATION SIGNAL CHART ".
Initial diagnosis of A/C auto amp.
Symptom
- Insufficient cooling
- No cool air comes out. (Air flow volume is normal.)
Symptom
- Insufficient heating
- No warm air comes out. (Air flow volume is normal.)
Symptom: Compressor does not operate.
See also:
• COMPONENT FUNCTION CHECK