Nissan Pathfinder: Heater & Air Conditioning Control System - Dtc/circuit Diagnosis

• Power Supply and Ground Circuit
• Sunload Sensor
• Door Motor
• Front Blower Motor
• Rear Blower Motor
• Magnetic Clutch
• Ecv (electrical Control Valve)
• Rear Blower Motor Resistor
• 4020 B20c7-11 A/c Clutch
• 4020 B20c7-15 A/c Clutch
• 4020 B2480-93 Rear Air Mix Door Motor
• 4020 B24a0-49 A/c Auto Amp.
• 4020 B24a1-16 A/c Amp. Power Supply
• 4020 B24a2-55 Configuration Not Implement
• 4020 B24a4-11 Intake Sensor
• 4020 B24a4-15 Intake Sensor
• 4020 B24a6-11 in-Vehicle Sensor
• 4021 B24a6-15 in-Vehicle Sensor
• 4021 B24b4-02 A/c Control Comm
• 4021 B24c6-12 Blower Motor Control
• 4021 B24f5-93 Mode Door Motor
• 4021 U1ca1-08 A/c Switch Assembly Communication
• 4021 U1ca2-08 Door Motor Communication
• 4021 U1caa-02 Mode Door Motor
• 4021 U2140-87 Can Comm Err (ecm)

Power Supply and Ground Circuit Nissan Pathfinder R53

A/c Auto Amp.

Diagnosis Procedure

CHECK A/C AUTO AMP. GROUND CIRCUIT FOR OPEN

1. Ignition switch OFF.

2. Disconnect A/C auto amp. connector.

3. Check continuity between A/C auto amp. harness connector and ground.

   A/C auto amp.		—	Continuity
   Connector	Terminal
   M60	58	Ground	Yes

Is the inspection result normal?

YES>>

GO TO 2.

NO>>

Repair harness or connector.

CHECK FUSE

Check that the following fuse is not blown (open):

Unit	Location	Fuse No.	Capacity
A/C auto amp.	Fuse block (J/B)	40	10 A

Is the fuse blown (open)?

YES>>

Replace the blown fuse after repairing the affected circuit.

NO>>

GO TO 3.

CHECK A/C AUTO AMP. POWER SUPPLY

1. Connect A/C auto amp. connector.

2. Check voltage between A/C auto amp. harness connector terminals.

   A/C auto amp.			Condition	Voltage (Approx.)
   Connector	Terminals
   	+	−
   M60	60	58	Ignition switch OFF (auto ACC status) or ON	Battery voltage
   			Ignition switch OFF (not auto ACC status)	0 V

Is the inspection result normal?

YES>>

Replace A/C auto amp. Refer to Removal and Installation.

NO>>

Repair the A/C auto amp. power supply circuit.

Front A/c Switch Assembly

Diagnosis Procedure

CHECK FUSE

1. Ignition switch OFF.

2. Check that the following fuse is not blown (open):

   Unit	Location	Fuse No.	Capacity
   Front A/C switch assembly	Fuse block (J/B)	40	10 A

Is the fuse blown (open)?

YES>>

Replace the blown fuse after repairing the affected circuit.

NO>>

GO TO 2.

CHECK FRONT A/C SWITCH ASSEMBLY POWER SUPPLY

1. Disconnect front A/C switch assembly connector.

2. Ignition switch ON.

3. Check voltage between front A/C switch assembly harness connector and ground.

   +		−	Voltage (Approx.)
   Front A/C switch assembly
   Connector	Terminal
   M69	1	Ground	Battery voltage

Is the inspection result normal?

YES>>

GO TO 3.

NO>>

Repair harness or connector between front A/C switch assembly and fuse.

CHECK FRONT A/C SWITCH ASSEMBLY GROUND CIRCUIT FOR OPEN

1. Ignition switch OFF.

2. Check continuity between front A/C switch assembly harness connector and ground.

   Front A/C switch assembly		—	Continuity
   Connector	Terminal
   M69	6	Ground	Yes

Is the inspection result normal?

YES>>

Replace front A/C switch assembly. Refer to Removal and Installation.

NO>>

Repair harness or connector.

Rear A/c Switch Assembly

Diagnosis Procedure

CHECK FUSE

1. Ignition switch OFF.

2. Check that the following fuse is not blown (open):

   Unit	Location	Fuse No.	Capacity
   Rear A/C switch assembly	Fuse block (J/B)	40	10 A

Is the fuse blown (open)?

YES>>

Replace the blown fuse after repairing the affected circuit.

NO>>

GO TO 2.

CHECK REAR A/C SWITCH ASSEMBLY POWER SUPPLY

1. Disconnect rear A/C switch assembly connector.

2. Ignition switch ON.

3. Check voltage between rear A/C switch assembly harness connector and ground.

   +		−	Voltage (Approx.)
   Rear A/C switch assembly
   Connector	Terminal
   M117	1	Ground	Battery voltage

Is the inspection result normal?

YES>>

GO TO 3.

NO>>

Repair harness or connector between rear air control and fuse.

CHECK REAR A/C SWITCH ASSEMBLY GROUND CIRCUIT FOR OPEN

1. Ignition switch OFF.

2. Check continuity between rear A/C switch assembly harness connector and ground.

   Rear A/C switch assembly		—	Continuity
   Connector	Terminal
   M117	6	Ground	Yes

Is the inspection result normal?

YES>>

Replace rear A/C switch assembly. Refer to Removal and Installation.

NO>>

Repair harness or connector.

Sunload Sensor Nissan Pathfinder 2022

Diagnosis Procedure

CHECK SUNLOAD SENSOR SIGNAL

1. Ignition switch ON.

2. Check voltage between A/C auto amp. harness connector.

   A/C auto amp.			Voltage (Approx.)
   Connector	Terminals
   	+	−
   M60	47	78
   	63

Is the inspection result normal?

YES>>

Inspection End.

NO>>

GO TO 2.

CHECK SUNLOAD SENSOR POWER SUPPLY

1. Ignition switch OFF.

2. Disconnect sunload sensor connector.

3. Ignition switch ON.

4. Check voltage between sunload sensor harness connector and ground.

   +		−	Voltage (Approx.)
   Sunload sensor
   Connector	Terminal
   M278	1	Ground	5 V
   	2

Is the inspection result normal?

YES>>

GO TO 3.

NO>>

GO TO 5.

CHECK SUNLOAD SENSOR GROUND CIRCUIT FOR OPEN

1. Ignition switch OFF.

2. Disconnect A/C auto amp. connector.

3. Check continuity between sunload sensor harness connector and A/C auto amp. harness connector.

   Sunload sensor		A/C auto amp.		Continuity
   Connector	Terminal	Connector	Terminal
   M278	3	M60	78	Yes

Is the inspection result normal?

YES>>

GO TO 4.

NO>>

Repair harness or connector.

REPLACE SUNLOAD SENSOR

Replace sunload sensor. Refer to Removal and Installation.

Is the inspection result normal?

YES>>

Inspection End.

NO>>

Replace A/C auto amp. Refer to Removal and Installation.

CHECK SUNLOAD SENSOR POWER SUPPLY CIRCUIT FOR OPEN

1. Ignition switch OFF.

2. Disconnect A/C auto amp. connector.

3. Check continuity between sunload sensor harness connector and A/C auto amp. harness connector.

   Sunload sensor		A/C auto amp.		Continuity
   Connector	Terminal	Connector	Terminal
   M278	1	M60	63	Yes
   	2		47

Is the inspection result normal?

YES>>

GO TO 6.

NO>>

Repair harness or connector.

CHECK SUNLOAD SENSOR POWER SUPPLY CIRCUIT FOR SHORT

Check continuity between sunload sensor harness connector and ground.

Sunload sensor		—	Continuity
Connector	Terminal
M278	1	Ground	No
	2

Is the inspection result normal?

YES>>

GO TO 4.

NO>>

Repair harness or connector.

Door Motor Nissan Pathfinder Fifth generation

Diagnosis Procedure

NOTE:

If all of door motor DTCs are detected, check this circuit.

CHECK DOOR MOTOR POWER SUPPLY

1. Ignition switch ON.

2. Check voltage between intake door motor harness connector and A/C auto amp. harness connector.

+		−		Voltage (Approx.)
Intake door motor		A/C auto amp.
Connector	Terminal	Connector	Terminal
M128	1	M60	58	Battery voltage

Is the inspection result normal?

YES>>

GO TO 2.

NO>>

GO TO 6.

CHECK DOOR MOTOR GROUND CIRCUIT FOR OPEN

1. Ignition switch OFF.

2. Disconnect intake door motor connector and A/C auto amp. connector.

3. Check continuity between intake door motor harness connector and A/C auto amp. harness connector.

   Intake door motor		A/C auto amp.		Continuity
   Connector	Terminal	Connector	Terminal
   M128	2	M50	27	Yes

Is the inspection result normal?

YES>>

GO TO 3.

NO>>

Repair harness or connector.

CHECK DOOR MOTOR LIN SIGNAL

1. Connect intake door motor connector and A/C auto amp. connector.

2. Ignition switch ON.

3. Confirm output waveform between intake door motor harness connector and A/C auto amp. harness connector with oscilloscope.

   +		−		Output waveform
   Intake door motor		A/C auto amp.
   Connector	Terminal	Connector	Terminal
   M128	3	M60	58

Is the inspection result normal?

YES>>

Inspection End.

NO>>

GO TO 4.

CHECK DOOR MOTOR LIN SIGNAL CIRCUIT FOR OPEN

1. Ignition switch OFF.

2. Disconnect A/C auto amp. and intake door motor connector.

3. Check continuity between intake door motor harness connector and A/C auto amp. harness connector.

   Intake door motor		A/C auto amp.		Continuity
   Connector	Terminal	Connector	Terminal
   M128	3	M50	2	Yes

Is the inspection result normal?

YES>>

GO TO 5.

NO>>

Repair harness or connector.

CHECK DOOR MOTOR LIN SIGNAL CIRCUIT FOR SHORT

1. Ignition switch OFF.

2. Disconnect following connectors:

   • Air mix door motor LH

   • Air mix door motor RH

   • Air mix door motor (rear)

   • Mode door motor (front)

   • Mode door motor (rear)

3. Check continuity between A/C auto amp. harness connector and ground.

   A/C auto amp.		—	Continuity
   Connector	Terminal
   M50	2	Ground	No

Is the inspection result normal?

YES>>

Replace A/C auto amp. Refer to Removal and Installation.

NO>>

Repair harness or connector.

CHECK DOOR MOTOR POWER SUPPLY CIRCUIT FOR OPEN

1. Ignition switch OFF.

2. Disconnect intake door motor and A/C auto amp. connector.

3. Check continuity between intake door motor harness connector and A/C auto amp. harness connector.

   Intake door motor		A/C auto amp.		Continuity
   Connector	Terminal	Connector	Terminal
   M128	1	M50	1	Yes

Is the inspection result normal?

YES>>

GO TO 7.

NO>>

Repair harness or connector.

CHECK DOOR MOTOR POWER SUPPLY CIRCUIT FOR SHORT

1. Disconnect following connectors:

   • Air mix door motor LH

   • Air mix door motor RH

   • Air mix door motor (rear)

   • Mode door motor (front)

   • Mode door motor (rear)

2. Check continuity between A/C auto amp. harness connector and ground.

   A/C auto amp.		—	Continuity
   Connector	Terminal
   M50	1	Ground	No

Is the inspection result normal?

YES>>

Replace A/C auto amp. Refer to Removal and Installation.

NO>>

Repair harness or connector.

Front Blower Motor Nissan Pathfinder 2025

Diagnosis Procedure

CHECK FUSIBLE LINK

1. Ignition switch OFF.

2. Check that the following fusible link is not blown (open):

   Unit	Location	Fusible link No.	Capacity
   Front blower motor	Fuse block (J/B)	FF	40 A

Is the fusible link blown (open)?

YES>>

Replace the blown fuse after repairing the affected circuit.

NO>>

GO TO 2.

CHECK FRONT BLOWER MOTOR POWER SUPPLY

1. Disconnect the front blower motor connector.

2. Ignition switch ON.

3. Check voltage between front blower motor harness connector and ground.

   +		−	Voltage (Approx.)
   Front blower motor
   Connector	Terminal
   M187	1	Ground	Battery voltage

Is the inspection result normal?

YES>>

GO TO 4.

NO>>

GO TO 3.

CHECK FRONT BLOWER MOTOR POWER SUPPLY CIRCUIT FOR OPEN

1. Ignition switch OFF.

2. Disconnect fuse block (J/B) harness connector.

3. Check continuity between fuse block (J/B) harness connector and front blower motor harness connector.

   Fuse block (J/B)		Front blower motor		Continuity
   Connector	Terminal	Connector	Terminal
   M3	1A	M187	1	Yes

Is the inspection result normal?

YES>>

Repair the front blower motor power supply circuit.

NO>>

Repair the harnesses or connectors.

CHECK FRONT BLOWER MOTOR GROUND CIRCUIT FOR OPEN

1. Ignition switch OFF.

2. Check continuity between front blower motor harness connector and ground.

   Front blower motor		—	Continuity
   Connector	Terminal
   M187	3	Ground	Yes

Is the inspection result normal?

YES>>

GO TO 5.

NO>>

Repair the harnesses or connectors.

CHECK FRONT BLOWER MOTOR CONTROL SIGNAL

1. Connect front blower motor connector.

2. Ignition switch ON.

3. Check duty ratios between front blower motor harness connector and ground by using an oscilloscope.

   +		−	Condition	Output waveform (Approx.)
   Front blower motor
   Connector	Terminal
   M187	2	Ground	Front blower motor: OFF	Battery voltage
   			Front blower motor: 1st speed (manual)
   			Front blower motor: 7th speed (manual)

Is the inspection result normal?

YES>>

Replace front blower motor. Refer to Removal and Installation.

NO>>

GO TO 6.

CHECK FRONT BLOWER MOTOR CONTROL SIGNAL CIRCUIT FOR OPEN

1. Ignition switch OFF.

2. Disconnect front blower motor connector and A/C auto amp. connector.

3. Check continuity between front blower motor harness connector and A/C auto amp. harness connector.

   Front blower motor		A/C auto amp.		Continuity
   Connector	Terminal	Connector	Terminal
   M187	2	M50	34	Yes

Is the inspection result normal?

YES>>

GO TO 7.

NO>>

Repair the harnesses or connectors.

REPLACE FRONT BLOWER MOTOR

1. Replace front blower motor. Refer to Removal and Installation.

2. Ignition switch ON.

3. Change fan speed from 1st – 7th, and check that front blower motor operates normally.

Is the inspection result normal?

YES>>

Inspection End.

NO>>

Replace the A/C auto amp. Refer to Removal and Installation.

Component Inspection (Front Blower Motor)

CHECK FRONT BLOWER MOTOR-I

1. Replace front blower motor. Refer to Removal and Installation.

2. Check that there is not any mixing foreign object in the front blower motor.

Is the inspection result normal?

YES>>

GO TO 2.

NO>>

Replace front blower motor. Refer to Removal and Installation.

CHECK FRONT BLOWER MOTOR-II

Check that there is not breakage or damage in the front blower motor.

Is the inspection result normal?

YES>>

GO TO 3.

NO>>

Replace front blower motor. Refer to Removal and Installation.

CHECK FRONT BLOWER MOTOR-III

Check that front blower motor turns smoothly.

Is the inspection result normal?

YES>>

Inspection End.

NO>>

Replace front blower motor. Refer to Removal and Installation.

Rear Blower Motor Nissan Pathfinder Fifth generation

Diagnosis Procedure

CHECK REAR BLOWER MOTOR POWER SUPPLY

1. Disconnect the rear blower motor connector.

2. Ignition switch ON.

3. Check voltage between rear blower motor harness connector and ground.

   +		−	Voltage (Approx.)
   Rear blower motor
   Connector	Terminal
   B126	1	Ground	Battery voltage

Is the inspection result normal?

YES>>

GO TO 3.

NO>>

GO TO 2.

CHECK REAR BLOWER MOTOR POWER SUPPLY CIRCUIT FOR OPEN

1. Ignition switch OFF.

2. Disconnect rear blower motor resistor connector.

3. Check continuity between rear blower motor resistor harness connector and rear blower motor harness connector.

   Rear blower motor resistor		Rear blower motor		Continuity
   Connector	Terminal	Connector	Terminal
   B134	1	B126	1	Yes

Is the inspection result normal?

YES>>

Repair the rear blower motor power supply circuit.

NO>>

Repair the harnesses or connectors.

CHECK REAR BLOWER MOTOR GROUND CIRCUIT FOR OPEN

1. Ignition switch OFF.

2. Check continuity between rear blower motor harness connector and ground.

   Rear blower motor		—	Continuity
   Connector	Terminal
   B126	2	Ground	Yes

Is the inspection result normal?

YES>>

GO TO 4.

NO>>

Repair the harnesses or connectors.

REPLACE REAR BLOWER MOTOR

1. Replace rear blower motor. Refer to Removal and Installation.

2. Ignition switch ON.

3. Change fan speed from 1st – 7th, and check that rear blower motor operates normally.

Is the inspection result normal?

YES>>

Inspection End.

NO>>

Replace the rear blower motor resistor. Refer to Removal and Installation.

Component Inspection (Rear Blower Motor)

CHECK REAR BLOWER MOTOR-I

1. Replace rear blower motor. Refer to Removal and Installation.

2. Check that there is not any mixing foreign object in the rear blower motor.

Is the inspection result normal?

YES>>

GO TO 2.

NO>>

Replace rear blower motor. Refer to Removal and Installation.

CHECK REAR BLOWER MOTOR-II

Check that there is not breakage or damage in the rear blower motor.

Is the inspection result normal?

YES>>

GO TO 3.

NO>>

Replace rear blower motor. Refer to Removal and Installation.

CHECK REAR BLOWER MOTOR-III

Check that rear blower motor turns smoothly.

Is the inspection result normal?

YES>>

Inspection End.

NO>>

Replace rear blower motor. Refer to Removal and Installation.

Magnetic Clutch Nissan Pathfinder Fifth generation

Component Function Check

CHECK MAGNETIC CLUTCH OPERATION

CONSULT

1. Select “HVAC TEST” in “Active Test” mode of “HVAC”.

2. Select “MODE 1”.

3. With operating the test item, check magnetic clutch operation by listening and viewing.

Does it operate normally?

YES>>

Inspection End.

NO>>

Refer to Diagnosis Procedure.

Diagnosis Procedure

CHECK MAGNETIC CLUTCH

CONSULT

1. Ignition switch ON.

2. Select “HVAC TEST” in “Active Test” mode of “HVAC”.

3. With operating the test item, check voltage between IPDM E/R harness connector and ground.

   +		−	Condition		Voltage (Approx.)
   IPDM E/R
   Connector	Terminal
   F24	65	Ground	Active test: HVAC TEST	Off	0 V
   				MODE 1	Battery voltage

Is the inspection result normal?

YES>>

GO TO 2.

NO>>

Replace IPDM E/R. Refer to Removal and Installation.

CHECK MAGNETIC CLUTCH POWER SUPPLY CIRCUIT FOR OPEN

1. Ignition switch OFF.

2. Disconnect IPDM E/R connector and A/C compressor connector.

3. Check continuity between IPDM E/R harness connector and A/C compressor harness connector.

   IPDM E/R		A/C compressor		Continuity
   Connector	Terminal	Connector	Terminal
   F24	65	F3	1	Yes

Is the inspection result normal?

YES>>

GO TO 3.

NO>>

Repair harness or connector.

CHECK MAGNETIC CLUTCH GROUND CIRCUIT FOR OPEN

Check continuity between A/C compressor harness connector and ground.

A/C compressor		—	Continuity
Connector	Terminal
F3	2	Ground	Yes

Is the inspection result normal?

YES>>

Replace A/C compressor. Refer to Removal and Installation.

NO>>

Repair harness or connector.

Ecv (electrical Control Valve) Nissan Pathfinder R53

Diagnosis Procedure

CHECK FUSE

1. Ignition switch OFF.

2. Check that the following fuse is not blown (open):

   Unit	Location	Fuse No.	Capacity
   A/C compressor	IPDM E/R	71	10 A

Is the fuse blown (open)?

YES>>

Replace the blown fuse after repairing the affected circuit.

NO>>

GO TO 2.

CHECK ECV POWER SUPPLY CIRCUIT

1. Disconnect A/C compressor connector.

2. Ignition switch ON.

3. Check voltage between A/C compressor harness connector and ground.

   +		−	Voltage (Approx.)
   A/C compressor
   Connector	Terminal
   F4	3	Ground	Battery voltage

Is the inspection result normal?

YES>>

GO TO 4.

NO>>

GO TO 3.

CHECK ECV POWER SUPPLY CIRCUIT FOR OPEN

1. Ignition switch OFF.

2. Disconnect IPDM E/R connector.

3. Check continuity between A/C compressor harness connector and IPDM E/R harness connector.

   A/C compressor		IPDM E/R		Continuity
   Connector	Terminal	Connector	Terminal
   F4	3	F24	71	Yes

Is the inspection result normal?

YES>>

Replace IPDM E/R. Refer to Removal and Installation.

NO>>

Repair harness or connector.

CHECK ECV CONTROL SIGNAL CIRCUIT FOR OPEN

1. Ignition switch OFF.

2. Disconnect IPDM E/R connector.

3. Check continuity between A/C compressor harness connector and IPDM E/R harness connector.

   A/C compressor		IPDM E/R		Continuity
   Connector	Terminal	Connector	Terminal
   F4	4	E78	98	Yes

Is the inspection result normal?

YES>>

GO TO 5.

NO>>

Repair harness or connector.

CHECK ECV

Check ECV. Refer to Component Inspection.

Is the inspection result normal?

YES>>

Replace IPDM E/R. Refer to Removal and Installation.

NO>>

Replace A/C compressor. Refer to Removal and Installation.

Component Inspection

CHECK ECV

1. Ignition switch OFF.

2. Check continuity between A/C compressor terminals.

A/C compressor		Continuity
Terminals
3	4	Yes

Is the inspection result normal?

YES>>

Inspection End.

NO>>

Replace A/C compressor. Refer to Removal and Installation.

Rear Blower Motor Resistor Nissan Pathfinder R53

Diagnosis Procedure

CHECK REAR BLOWER MOTOR RESISTOR POWER SUPPLY CIRCUIT

1. Ignition switch OFF.

2. Disconnect rear blower motor resistor connector.

3. Ignition switch ON.

4. Check voltage between rear blower motor resistor harness connector and ground.

   +		—	Voltage (Approx.)
   Rear blower motor resistor
   Connector	Terminal
   B133	6	Ground	Battery voltage

Is the inspection result normal?

YES>>

GO TO 2.

NO>>

GO TO 5.

CHECK REAR BLOWER MOTOR RESISTOR GROUND CIRCUIT

1. Ignition switch OFF.

2. Check continuity between rear blower motor resistor harness connector and ground.

   Rear blower motor resistor		—	Continuity
   Connector	Terminal
   B133	4	Ground	Yes

Is the inspection result normal?

YES>>

GO TO 3.

NO>>

Repair harness or connector.

CHECK REAR BLOWER MOTOR RESISTOR SIGNAL CIRCUIT FOR OPEN

1. Disconnect A/C auto amp. connector.

2. Check continuity between rear blower motor resistor harness connector and A/C auto amp. harness connector.

   Rear blower motor resistor		A/C auto amp.		Continuity
   Connector	Terminal	Connector	Terminal
   B133	5	M60	74	Yes

Is the inspection result normal?

YES>>

GO TO 4.

NO>>

Repair harness or connector.

CHECK REAR BLOWER MOTOR RESISTOR SIGNAL CIRCUIT FOR SHORT

Check continuity between rear blower motor resistor harness connector and ground.

Rear blower motor resistor		—	Continuity
Connector	Terminal
B133	5	Ground	No

Is the inspection result normal?

YES>>

Replace rear blower motor resistor. Refer to Removal and Installation.

NO>>

Repair harness or connector.

CHECK REAR BLOWER MOTOR RESISTOR POWER SUPPLY CIRCUIT FOR OPEN

1. Ignition switch OFF.

2. Disconnect fuse block(J/B) connector.

3. Check continuity between rear blower motor resistor harness connector and fuse block(J/B) harness connector.

   Rear blower motor resistor		Fuse block(J/B)		Continuity
   Connector	Terminal	Connector	Terminal
   B133	6	B34	7M	No

Is the inspection result normal?

YES>>

Check the 20A fuse [No. 64, located in fuse block (J/B)].

NO>>

Repair harness or connector.