Nissan Pathfinder: Heater & Air Conditioning Control System - System Description

Nissan Pathfinder (R53) 2022-2025 Service Manual / Ventilation, Heater & Air Conditioner :: Heater & Air Conditioning Control System / Automatic Air Conditioning / System Description

Component Parts ➤ Nissan Pathfinder 2025

System ➤ Nissan Pathfinder R53

Operation ➤ Nissan Pathfinder 2025

Diagnosis System (hvac) Nissan Pathfinder 2025

CONSULT Function

CONSULT performs the following functions via CAN communication with A/C auto amp.:

Diagnostic mode	Description
Self Diagnostic Result	Display non-network DTC which A/C auto amp. memorizes.
Data Monitor	Displays the input/output signal of A/C auto amp.
Active Test	The signals used to activate each device are forcibly supplied from A/C auto amp.
Work support	Changes the setting for each setting function.
ECU Identification	Displays the part number of A/C auto amp.
Network-DTC*	Display network DTC which A/C auto amp. memorizes when performing “Diagnosis (All System)”.

*: Displays when performing “Diagnosis (All System)”.

NOTE:

Diagnosis should be performed with engine running. Door motor operation speeds become slower and NO results may be returned even for normal operation if battery voltage drops below 12 V during self-diagnosis.

SELF-DIAGNOSIS RESULTS

Diagnosis result that is judged by A/C auto amp. can be checked. Refer to DTC Index.

DATA MONITOR

Input/output signal of A/C auto amp. can be checked.

NOTE:

The following table includes information (items) inapplicable to this Nissan Pathfinder vehicle: For information (items) applicable to this vehicle, refer to CONSULT display items.

Display item list
Monitor item [Unit]		Description
IN-VEH TEMP	[°C]	In-Nissan Pathfinder vehicle temperature value converted from in-vehicle sensor signal received from in-vehicle sensor.
INT TEMP SEN	[°C]	Evaporator fin temperature value converted from intake sensor signal received from intake sensor.
SUNLOAD SEN	[W/m^2]	Sunload value converted from sunload sensor signal received from sunload sensor.
AMB SEN CAL	[°C]	Ambient temperature value calculated by A/C auto amp.
IN-VEH CAL	[°C]	In-Nissan Pathfinder vehicle temperature (driver side) value calculated by A/C auto amp.
PASS IN CAL	[°C]	In-Nissan Pathfinder vehicle temperature (RH side) value calculated by A/C auto amp.
INT TEMP CAL	[°C]	Evaporator fin temperature value calculated by A/C auto amp.
SUNL SEN CAL	[W/m^2]	Sunload value calculated by A/C auto amp.
XM		Target discharge air temperature (LH side) judged by A/C auto amp. depending on the temperature setting and the value from each sensor.
FAN REQ SIG	[On/Off]	Displays blower fan ON signal ON/OFF status transmitted to ECM.
COMP REQ SIG	[On/Off]	Displays A/C ON signal ON/OFF status transmitted to ECM.
A/C comp clutch status	[On/Off]	A/C compressor status judged from the A/C compressor feedback signal received from IPDM E/R via CAN communication.
RR XM	[°C]	Target discharge air temperature (rear) judged by A/C auto amp. depending on the temperature setting and the value from each sensor.
Assist seat target air temperature		Target discharge air temperature (RH side) judged by A/C auto amp. depending on the temperature setting and the value from each sensor.
Blower fan duty	[%]	Duty ratio of front blower motor judged by A/C auto amp.
Compressor ECV duty	[%]	Duty ratio of electric control valve
AMB TEMP SEN	[°C]	Ambient temperature signal value received from combination meter via CAN communication.
Nissan Pathfinder Vehicle speed	[km/h]	Vehicle speed signal value received from ABS actuator and electric unit (control unit) via CAN communication.
ODO/TRIP METER	[km]	Odometer signal value received from ABS actuator and electric unit (control unit) via CAN communication.
Engine RPM	[rpm]	Engine speed signal value received from ECM via CAN communication.
ENG COOL TEMP	[°C]	Engine coolant temperature signal value received from ECM via CAN communication.

WORK SUPPORT

Setting change of each setting functions can be performed.

Work support items	Description	Display	Setting
TEMP SET CORRECT	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.	0.0°C/0°F^*	A/C auto amp. control temperature against set temperature can be set (-3.0)°C/(-6)°F – (+3.0)°C/(+6)°F at a rate of 0.5°C/1°F per adjustment. NOTE: When −3.0°C (−6°F) is corrected on the temperature setting set as 25.0°C (77°F) the temperature controlled by A/C auto amp. is 25.0°C (77°F) −3.0°C (−6°F) = 22.0°C (72°F) and the temperature becomes lower than the temperature setting.
REC MEMORY SET	NOTE: This item displayed, but cannot be used.
FRE MEMORY SET	NOTE: This item displayed, but cannot be used.
BLOW SET	In FOOT mode, the air blowing to DEF can change ON/OFF.	O/A C/M^*	Auto control: Defroster door position (open) Manual control: Defroster door position (close)
		O/A O/M	Auto control: Defroster door position (open) Manual control: Defroster door position (open)
		C/A O/M	Auto control: Defroster door position (close) Manual control: Defroster door position (open)
		C/A C/M	Auto control: Defroster door position (close) Manual control: Defroster door position (close)
TARGET EVAPORATOR TEMP UPPER LIMIT SETTING	Setting of upper limit value of target evaporator temperature can be changed. Control characteristic of A/C compressor control (freezing protection control and refrigerant discharge amount control) changes according to change of the setting, and then operation ratio of A/C compressor and refrigerant discharge amount are changed. According to change of the setting, control characteristic focusing on the fuel consumption can be adjusted to control characteristic focusing on the cooling capacity.	DEFAULT^*	Target evaporator temperature upper limit value: 10°C (50°F)
		3°C	Target evaporator temperature upper limit value: 3°C (37°F)
		5°C	Target evaporator temperature upper limit value: 5°C (41°F)
		7°C	Target evaporator temperature upper limit value: 7°C (45°F)
STOP/START SYSTEM OPERATION COND SETTING	NOTE: This item displayed, but cannot be used.
AIR INLET CHANGE SETTING	NOTE: This item displayed, but cannot be used.
AIR FLOW REDUCTION SETTING	NOTE: This item displayed, but cannot be used.

*: Initial status

NOTE:

When the battery cable is disconnected from the negative terminal or when the battery voltage is 10 V or less, the setting for the work support item is set to the value stored 1 minute after most recent ignition switch OFF status.

ACTIVE TEST

The signals used to activate each device forcibly supplied from A/C auto amp. operation check of air conditioning system can be performed.

Test item	Operation	Description
HVAC TEST		The operation check of air conditioning system can be performed by selecting the mode. Refer to the following table for the conditions of each mode.
Heater and ventilation seat FL	Off	OFF
	Heat HI	Operates the front seat heater LH.
	Vent HI	NOTE: This item displayed, but cannot be tested.
Heater and ventilation seat FR	Off	OFF
	Heat HI	Operates the front seat heater RH.
	Vent HI	NOTE: This item displayed, but cannot be tested.
Heated steering wheel request	Heated steering wheel request	Operates the heated steering wheel relay.
Heated steering wheel request	Off	OFF

Check each output device

—	Test item
—	MODE 1	MODE 2	MODE 3	MODE 4	MODE 5	MODE 6	MODE 7
Mode door motor position	VENT	VENT	B/L	B/L	FOOT	D/F	DEF
Intake door motor position	REC	REC	20% FRE	20% FRE	FRE	FRE	FRE
Magnetic clutch (A/C compressor request signal)	ON	ON	ON	ON	OFF	OFF	ON
Air mix door motor LH position	FULL COLD	FULL HOT	FULL COLD	FULL HOT	FULL HOT	FULL HOT	FULL HOT
Air mix door motor RH position	FULL COLD	FULL HOT	FULL COLD	FULL HOT	FULL HOT	FULL HOT	FULL HOT
Air mix door motor (rear) position	FULL COLD	FULL HOT	FULL COLD	FULL HOT	FULL HOT	FULL HOT	FULL HOT
Front blower motor control signal (duty ratio)	35%	35%	60%	60%	90%	90%	35%
ECV duty ratio	80%	80%	40%	40%	0%	0%	90%