Nissan Sentra B18 (2020-2025) Service Manual: Heater and Air Conditioning System Control Symptoms

• Air conditioning does not activate.

• Air conditioning cannot be controlled.

• Operation status of air conditioning is not indicated on display.

• A/C auto amp. ignition power supply circuit

• A/C switch assembly

• A/C auto amp.

Refer to Diagnosis Procedure.

• Air outlet does not change.

• Mode door motor does not operate normally.

• Circuit between mode door motor and A/C auto amp.

• Mode door motor control linkage

• Mode door motor

• A/C auto amp.

Refer to DTC Diagnosis Procedure.

• Discharge air temperature of driver side does not change.

• Air mix door motor LH does not operate normally.

• Circuit between air mix door motor LH and A/C auto amp.

• Air mix door motor LH installation condition

• Air mix door motor LH

• A/C auto amp.

Refer to DTC Diagnosis Procedure.

• Discharge air temperature of passenger side does not change.

• Air mix door motor RH does not operate normally.

• Circuit between air mix door motor RH and A/C auto amp.

• Air mix door motor RH installation condition

• Air mix door motor RH

• A/C auto amp.

Refer to DTC Diagnosis Procedure.

• Intake door does not change.

• Intake door motor does not operate normally.

• Circuit between intake door motor and A/C auto amp.

• Intake door motor control linkage

• Intake door motor

• A/C auto amp.

Refer to DTC Diagnosis Procedure.

Blower motor operation is malfunctioning.

• Power supply system of blower motor

• Circuit between blower motor and A/C auto amp.

• Blower motor

• A/C auto amp.

Refer to Diagnosis Procedure

Compressor does not operate.

• Circuit between magnet clutch and IPDM E/R

• Magnet clutch

• IPDM E/R

• Circuit between ECM and refrigerant pressure sensor

• Refrigerant pressure sensor

• CAN communication circuit

• A/C auto amp.

Refer to Diagnosis Procedure.

• Insufficient cooling.

• No cool air comes out. (Air flow volume is normal.)

• Magnet clutch control system

• Drive belt slipping

• Refrigerant cycle

• ECV (electrical control valve)

• Air leakage from each duct

• A/C auto amp. connection recognition signal circuit

• Temperature setting trimmer (front)

Refer to Diagnosis Procedure.

• Insufficient heating.

• No warm air comes out. (Air flow volume is normal.)

• Engine cooling system

• Heater hose

• Heater core

• Air leakage from each duct

• Temperature setting trimmer (front)

Refer to Diagnosis Procedure.

Noise is heard when front air conditioning system operates.

During A/C compressor operation

Refrigerant cycle

Refer to Symptom Table.

During blower motor operation

• Mixing any foreign object in blower motor

• Blower motor fan breakage

• Blower motor rotation inferiority

Refer to Component Inspection (Blower Motor).

• Memory function does not operate.

• Setting temperature is not memorized.

• Battery power supply system of A/C auto amp.

• A/C auto amp.

Refer to Diagnosis Procedure.