Nissan Altima (L32) 2007-2012 Service Manual: Blower motor

Description

SYSTEM DESCRIPTION

Component Parts

Fan speed control system components are: • Front air control

• A/C LAN system (PBR built-in mode door motor, air mix door motor and intake door motor)

System Operation

Component Function Check

INSPECTION FLOW

1. CONFIRM SYMPTOM BY PERFORMING OPERATION CHECK - FRONT BLOWER

1. Rotate the blower control dial clockwise. Blower should operate.

2. Rotate the blower control dial clockwise, and continue checking blower speed until all speeds are checked.

Can a symptom be duplicated? YES >> GO TO 3.

NO >> GO TO 2.

2. PERFORM COMPLETE OPERATIONAL CHECK

Perform a complete operational check and check for any symptoms. Refer to HAC-155, "Symptom Matrix Chart".

Is the inspection result normal? YES >> Refer to HAC-155, "Symptom Matrix Chart".

NO >> System OK.

3. CHECK FOR SERVICE BULLETINS

Check for any service bulletins.

>> GO TO 4.

4. CHECK BLOWER MOTOR OPERATION

Check and verify blower motor operates in all speeds.

Does blower motor operate in all speeds?

YES >> GO TO 5.

NO >> Refer to HAC-127, "Diagnosis Procedure".

5. RECHECK FOR SYMPTOMS

Perform a complete operational check and check for any symptoms. Refer to HAC-155, "Symptom Matrix Chart".

Does another symptom exist? YES >> Repair as necessary.

NO >> Replace front air control. Refer to VTL-8, "Removal and Installation".

Diagnosis Procedure

SYMPTOM: Blower motor operation is malfunctioning.

DIAGNOSIS PROCEDURE FOR BLOWER MOTOR

SYMPTOM: Blower motor operation is malfunctioning under starting blower speed control.

1.CHECK POWER SUPPLY FOR BLOWER MOTOR

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

2. Press ignition switch ON.

3. Check voltage between fuse block (J/B) harness connector E6 terminal P6 and ground.

Is the inspection result normal? YES >> GO TO 2.

NO >> Check power supply circuit and 15A fuses [Nos. 21 and 22, located in the fuse block (J/B)].

• If OK, check for open circuit in wiring harness.

Repair or replace as necessary.

• If OK, check fuses and check wiring harness for possible open or short circuit.

• If OK, GO TO 5.

2.CHECK BODY GROUND CIRCUIT FOR BLOWER MOTOR

1. Disconnect blower motor connector.

2. Press ignition switch OFF.

3. Check continuity between blower motor harness connector M31 terminal 1 and ground.

Is the inspection result normal? YES >> Reconnect blower motor harness connector and GO TO 3.

NO >> Repair harness or connector.

3.CHECK BLOWER MOTOR CONTROL CIRCUIT BETWEEN BLOWER MOTOR AND FRONT AIR CONTROL

1. Disconnect front air control harness connector.

2. Check continuity between blower motor harness connector M31 (A) terminal 3 and front air control harness connector M37 (B) terminal 1.

Is the inspection result normal? YES >> GO TO 4.

NO >> Repair harness or connector.

4.CHECK POWER SUPPLY FOR FRONT AIR CONTROL

1. Press ignition switch ON.

2. Check voltage between front air control harness connector M37 terminals 39, 40 and ground.

Is the inspection result normal? YES >> 1. Replace front air control. Refer to VTL-8, "Removal and Installation".

2. Confirm that blower motor operation is normal.

NO >> • Check for open circuit in wiring harness.

Repair or replace as necessary.

• If OK, replace fuse and check wiring harness for short circuit.

Repair or replace an necessary.

5.CHECK POWER SUPPLY FOR FRONT BLOWER MOTOR RELAY

1. Connect fuse block (J/B) connector.

2. Press ignition switch ON.

3. Turn blower motor control dial to any speed except OFF.

4. Check voltage between fuse block (J/B) E6 terminal 6P and ground.

6P - Ground : Battery Voltage

Is the inspection result normal? YES >> GO TO 9.

NO >> GO TO 6.

6.CHECK POWER SUPPLY FOR FRONT BLOWER MOTOR RELAY FOR AN OPEN

1. Press ignition switch OFF.

2. Disconnect BCM harness connector M19.

3. Check continuity between BCM harness connector M19 (A) terminal 90 and fuse block (J/B) harness connector E6 (B) terminal 6P.

Is the inspection result normal? YES >> GO TO 7.

NO >> Repair harness or connector.

7.CHECK BLOWER FAN SWITCH SIGNAL FOR VOLTAGE

1. Press ignition switch ON.

2. Disconnect BCM harness connector M18.

3. Check voltage between BCM harness connector M18 terminal 55 and ground.

Is the inspection result normal? YES >> Replace BCM. Refer to BCS-96, "Removal and Installation".

NO >> GO TO 8.

8.CHECK BLOWER FAN SWITCH SIGNAL CIRCUIT FOR AN OPEN

1. Press ignition switch OFF.

2. Disconnect front air control harness connector.

3. Check continuity between BCM harness connector M18 (A) terminal 55 and front air control harness connector M37 (B) terminal 24.

Is the inspection result normal? YES >> Replace front air control. Refer to VTL-8, "Removal and Installation".

NO >> Repair harness or connector.

9.CHECK FRONT BLOWER MOTOR RELAY GROUND

1. Press ignition switch OFF.

2. Disconnect fuse block (J/B) harness connector M5.

3. Check continuity between fuse block (J/B) harness connector M5 terminal 7M and ground.

Is the inspection result normal? YES >> Replace front blower motor relay.

NO >> Repair harness or connector.