Nissan Versa

 Sedan Service Manual

Ventilation, heater & air conditioner » Heater & air conditioning control system (HAC)
A/C On signal

Component Function Check

1.CHECK A/C ON SIGNAL

With CONSULT

1. Turn ignition switch ON.
2. Operate front blower motor.
3. Select "AIR CONDITIONER" of "BCM" using CONSULT.
4. Select "AIR COND SW" in "DATA MONITOR" mode, and check status under the following condition.   

Is the inspection result normal?

YES >> Inspection End.

NO >> Refer to HAC "Diagnosis Procedure".

Diagnosis Procedure

Regarding Wiring Diagram information, refer to HAC "Wiring Diagram".

1.CHECK FUSE

1. Turn ignition switch OFF.
2. Check 10A fuse (No. 21, located in fuse block (J/B)].

NOTE: Refer to PG "Terminal Arrangement".

Is the inspection result normal?

YES >> GO TO 2.

NO >> Replace the blown fuse after repairing the affected circuit.

2.CHECK THERMO CONTROL AMP. POWER SUPPLY

1. Turn ignition switch OFF.
2. Disconnect thermo control amp. connector.
3. Turn ignition switch ON.
4. Check voltage between thermo control amp. harness connector and ground.  

Is the inspection result normal?

YES >> GO TO 3.

NO >> Repair harness or connector between thermo control amp. and fuse.

3.CHECK THERMO CONTROL AMP. GROUND CIRCUIT FOR OPEN

1.  Turn ignition switch OFF.
2. Check continuity between thermo control amp. harness connector and ground  

Is the inspection result normal?

YES >> GO TO 4.

NO >> Repair harness or connector.

4.CHECK A/C ON SIGNAL

1. Turn ignition switch ON.
2. Check output waveform between thermo control amp. harness connector and ground with using oscilloscope.

Is the inspection result normal?

YES >> GO TO 5.

NO >> GO TO 6.

5.CHECK FRONT AIR CONTROL

1. Turn ignition switch OFF.
2. Check front air control. Refer to HAC "Component Inspection".

Is the inspection result normal?

YES >> Replace thermo control amp. Refer to HAC "Removal and Installation".

NO >> Replace front air control. Refer to HAC "Removal and Installation".

6.CHECK A/C ON SIGNAL CIRCUIT FOR OPEN

1. Turn ignition switch OFF.
2. Disconnect BCM and front air control connector.
3. Check continuity between thermo control amp. harness connector and BCM harness connector.
4. Check continuity between front air control harness connector and BCM harness connector.

Is the inspection result normal?

YES >> Replace BCM. Refer to BCS "Removal and Installation" or BCS "Removal and Installation".

NO >> Repair harness or connector.

Component Inspection

1.CHECK A/C CONTROL

Check continuity front air control terminals.                   

Is the inspection result normal?

YES >> Inspection End.

NO >> Replace front air control. Refer to HAC "Removal and Installation".

Precautions

Manual air conditioning system

Diagnosis and repair workflow

Operation inspection

A/C On signal

Blower fan on signal

A/C Indicator

Front blower motor

Magnet clutch

Insufficient cooling

Insufficient heating

Compressor does not operate

Front air control

Refrigerant pressure sensor

Blower fan resistor

Intake door cable

Mode door cable

Air mix door cable