Heater & Automatic Air Conditioning: Overview Nissan Juke I

Component Description

STRUCTURE AND OPERATION

1. The refrigerant pressure sensor is a capacitance type sensor. It consists of a pressure detection areas and a signal processing area.
2. The pressure detection area, which is a variable capacity condenser, changes internal static capacitance according to pressure force.
3. The signal processing area detects the static capacitance of the pressure detection area, converts the static capacitance into a voltage value, and transmits the voltage value to ECM.

DESCRIPTION

1. Automatic air conditioning system is controlled by each function of A/C auto amp., BCM, ECM and IPDM E/R.
2. Each operation of air conditioning system is transmitted from multi display unit via CAN communication. A/C auto amp. transmits each type of indication information to multi display unit via CAN communication. Multi display unit displays each type of indication information that is received.

1. A/C auto amp. changes gate voltage of power transistor and controls air flow continuously. When air flow is increased, voltage of blower motor gradually increases to prevent a sudden increase in air flow.
2. In addition to manual control and automatic control, air flow control is compose of starting fan speed control, low coolant temperature starting control, high in-vehicle temperature starting control, and blower speed control at door motor operation.

Scheme 75

1. A/C auto amp. decides target air flow depending on target air mix door opening angle.
2. A/C auto amp. changes voltage of blower motor and controls air flow continuously so that air flow matches to target air flow.
3. When air outlet is VENT or B/L, the minimum air flow is changed depending on sunload.

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 temporarily fan speed so that mode door moves smoothly.

1. 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.
2. BCM transmits the A/C ON signal and blower fan ON signal to ECM via CAN communication line. Refer to " «SIGNAL BUFFER SYSTEM: SYSTEM DESCRIPTION»(ref-516421-S03140821922012120600000) ".
3. ECM judges the conditions of each sensor (Refrigerant pressure sensor signal, accelerator position signal, etc.), and transmits the A/C compressor request signal to IPDM E/R via CAN communication line.
4. By receiving the A/C compressor request signal from ECM, IPDM E/R turns the A/C relay to ON, and activates the compressor. Refer to " «RELAY CONTROL SYSTEM: SYSTEM DESCRIPTION»(ref-516417-S12950088432012120600000) ".

1. A/C auto amp. receives operation status of each switch (A/C operation signal), D-MODE setting status (ECO mode signal), and "CLIMATE ECO" setting status (A/C ECO setting signal) from multi display unit via CAN communication.
2. A/C auto amp. operates air conditioning system in ECO mode, when D-MODE on multi display unit is set to ECO mode while air conditioning system is in automatic control. NOTE: For setting procedure of D-MODE, refer to " «INTEGRATED CONTROL SYSTEM: SYSTEM DESCRIPTION»(ref-516457-S26960109242012120600000) ". Activation or deactivation of ECO mode can be changed using multi display unit setting function ("CLIMATE ECO"). For setting procedure, refer to " «INTEGRATED CONTROL SYSTEM: SYSTEM DESCRIPTION»(ref-516457-S26960109242012120600000) ".

Air conditioning system performs self-diagnosis, operation check, function diagnosis, and various settings using diagnosis function of each control unit.

ECU IDENTIFICATION

Part number of A/C auto amp. can be checked.

If the temperature felt by the customer is different from the air flow temperature controlled by the temperature setting, the A/C auto amp. control temperature can be adjusted to compensate for the temperature setting.

1. If the ignition switch is turned to the OFF position while the intake switch is set to ON (recirculation), "Perform the memory" or "Do not perform the memory" of intake switch ON (recirculation) condition can be selected.
2. If "Perform the memory" was set, the intake switch will be ON (recirculation) when turning the ignition switch to the ON position again.
3. 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.

1. If the ignition switch is turned to the OFF position while the intake switch is set to OFF (fresh air intake), "Perform the memory" or "Do not perform the memory" of intake switch OFF (fresh air intake) condition can be selected.
2. If "Perform the memory" was set, the intake switch will be OFF (fresh air intake) when turning the ignition switch to the ON position again.
3. 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.

In FOOT mode, the air blowing to DEF can change ON/OFF.

1. Reset signal is transmitted from A/C auto amp. to air mix door motor and mode door motor. Starting position reset can be performed. NOTE: During reset, DEF switch indicator blinks.
2. When air mix 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 line for real time applications. It is an on-board multiplex communication line with high data communication speed and excellent error detection ability. A modern vehicle is equipped with many ECMs, and each control unit shares information and links with other control units during operation (not independent). In CAN communication, 2 control units are connected with 2 communication lines (CAN-L line and CAN-H 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 " for details of the communication signal.

Initial diagnosis of A/C auto amp.

See also:
• COOLING FAN CONTROL: SYSTEM DESCRIPTION