Nissan Altima L32. Manual - part 588

COOLING FAN

EC-1473

< COMPONENT DIAGNOSIS >

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COOLING FAN

Description

INFOID:0000000004362351

The ECM controls the cooling fan corresponding to the vehicle speed, engine coolant temperature, refrigerant

pressure, and air conditioner ON signal. The control system has 4-step control [HIGH/MIDDLE/LOW/OFF].

COOLING FAN MOTOR

The cooling fan operates at each speed when the current flows in the cooling fan motor as per the following.

The cooling fan operates at low (LOW) speed when cooling fan motors-1 and -2 are circuited in series under

the middle speed condition.

Refer to 

EC-1099, "System Diagram"

.

Component Function Check

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1.

CHECK COOLING FAN FUNCTION

With CONSULT-III

1. Turn ignition switch ON.

2. Perform “COOLING FAN” in “ACTIVE TEST” mode with CONSULT-III.

3. Check that cooling fan operates at each speed.

Without CONSULT-III

1. Perform IPDM E/R auto active test and check cooling fan motors operation, refer to 

PCS-14, "Diagnosis

Description"

.

2. Check that cooling fan operates at each speed.
Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Go to 

EC-1473, "Diagnosis Procedure"

.

Diagnosis Procedure

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1.

CHECK COOLING FAN RELAY POWER SUPPLY CIRCUIT

1. Turn ignition switch OFF.

2. Disconnect cooling fan relays-2, -3.

3. Turn ignition switch ON.

4. Check the voltage between cooling fan relays-2, -3 harness con-

nectors and ground.

Is the inspection result normal?

YES

>> GO TO 3.

Cooling fan speed

Cooling fan motor terminals

(+)

(–)

Middle (MID)

1

3 and 4

2

3 and 4

1 and 2

3

1 and 2

4

High (HI)

1 and 2

3 and 4

Cooling fan relay

Ground

Voltage

Connector

Terminal

E42

(cooling fan relay-2)

2

Ground

Battery voltage

5

E43

(cooling fan relay-3)

2

5

PBIB0071E

EC-1474

< COMPONENT DIAGNOSIS >

[VQ35DE]

COOLING FAN

NO

>> GO TO 2.

2.

DETECT MALFUNCTIONING PART

Check the following.

• 10 A fuse (No. 33)

• 40 A fusible link (letter K)

• IPDM E/R harness connector E18

• Harness for open or short between cooling fan relay-2 and battery

• Harness for open or short between cooling fan relay-3 and battery

• Harness for open or short between cooling fan relay-2 and IPDM E/R

• Harness for open or short between cooling fan relay-3 and IPDM E/R

>> Repair open circuit, short to ground or short to power in harness or connectors.

3.

CHECK COOLING FAN RELAY OUTPUT SIGNAL CIRCUIT

1. Turn ignition switch OFF.

2. Disconnect IPDM E/R harness connectors.

3. Check the continuity between cooling fan relay-2, -3 harness connectors and IPDM E/R harness connec-

tor.

4. Also check harness for short to ground and short to power.
Is the inspection result normal?

YES

>> GO TO 5.

NO

>> GO TO 4.

4.

DETECT MALFUNCTIONING PART

Check the following.

• Harness for open or short between cooling fan relay-2 and IPDM E/R

• Harness for open or short between cooling fan relay-3 and IPDM E/R

>> Repair open circuit, short to ground or short to power in harness or connectors.

5.

CHECK COOLING FAN MOTOR POWER SUPPLY CIRCUIT

1. Disconnect cooling fan motor-1 harness connector.

2. Check the voltage between cooling fan motor-1 harness con-

nector and ground.

Is the inspection result normal?

YES

>> GO TO 7.

NO

>> GO TO 6.

6.

DETECT MALFUNCTIONING PART

Check the following.

• 40 A fusible link (letter M)

• Harness connector E12, E203

• Harness for open or short between cooling fan motor-1 and battery

Cooling fan relay

IPDM E/R

Continuity

Connector

Terminal

Connector

Terminal

E42

(cooling fan relay-2)

1

E17

42

Existed

E43

(cooling fan relay-3)

1

E18

34

Cooling fan motor-1

Ground

Voltage

Connector

Terminal

E220

1

Ground

Battery voltage

2

PBIB1670E

COOLING FAN

EC-1475

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>> Repair open circuit, short to ground or short to power in harness or connectors.

7.

CHECK COOLING FAN MOTOR CIRCUIT-I

1. Disconnect cooling fan motor-2 harness connector.

2. Check the continuity between cooling fan relay-2, -3 harness connectors and cooling fan motor-1, -2 har-

ness connectors.

3. Also check harness for short to ground and short to power.
Is the inspection result normal?

YES

>> GO TO 9.

NO

>> GO TO 8.

8.

DETECT MALFUNCTIONING PART

Check the following.

• Harness connector E12, E203

• Harness for open or short between cooling fan motor-1 and cooling fan relay-2

• Harness for open or short between cooling fan motor-1 and cooling fan relay-3

• Harness for open or short between cooling fan motor-2 and cooling fan relay-2

• Harness for open or short between cooling fan motor-2 and cooling fan relay-3

>> Repair open circuit, short to ground or short to power in harness or connectors.

9.

CHECK COOLING FAN MOTOR CIRCUIT-II

1. Check the continuity between IPDM E/R harness connector and cooling fan motor-1, -2 harness connec-

tor.

2. Also check harness for short to ground and short to power.
Is the inspection result normal?

YES

>> GO TO 11.

NO

>> GO TO 10.

10.

DETECT MALFUNCTIONING PART

Check the following.

• Harness connector E70, E305

• Harness for open or short between cooling fan motor-1 and IPDM E/R

• Harness for open or short between cooling fan motor-2 and IPDM E/R

>> Repair open circuit, short to ground or short to power in harness or connectors.

Cooling fan relay

Cooling fan motor

Continuity

Connector

Terminal

Connector

Terminal

E42

(cooling fan relay-2)

3

E221

(Cooling fan motor-2)

2

Existed

7

E220

(Cooling fan motor-1)

3

E43

(cooling fan relay-3)

3

E221

(Cooling fan motor-2)

1

7

E220

(Cooling fan motor-1)

4

IPDM E/R

Cooling fan motor

Continuity

Connector

Terminal

Connector

Terminal

E18

35

E220

(Cooling fan motor-1)

4

Existed

38

E221

(Cooling fan motor-2)

1

EC-1476

< COMPONENT DIAGNOSIS >

[VQ35DE]

COOLING FAN

11.

CHECK COOLING FAN MOTOR CIRCUIT-III

1. Check the continuity between cooling fan relay-2, -3 harness connectors and ground.

2. Also check harness for short to ground and short to power.
Is the inspection result normal?

YES

>> GO TO 12.

NO

>> Repair open circuit, short to ground or short to power in harness or connectors.

12.

CHECK COOLING FAN MOTOR CIRCUIT-IV

1. Check the continuity between cooling fan motor-2 harness connector and ground.

2. Also check harness for short to ground and short to power.
Is the inspection result normal?

YES

>> GO TO 13.

NO

>> Repair open circuit, short to ground or short to power in harness or connectors.

13.

CHECK COOLING FAN RELAYS-2 AND -3

Refer to 

EC-1477, "Component Inspection (Cooling Fan Relay)"

.

Is the inspection result normal?

YES

>> GO TO 14.

NO

>> Replace malfunctioning cooling fan relay.

14.

CHECK COOLING FAN MOTORS-1 AND -2

Refer to 

EC-1476, "Component Inspection (Cooling Fan Motor)"

.

Is the inspection result normal?

YES

>> GO TO 15.

NO

>> Replace malfunctioning cooling fan motor.

15.

CHECK INTERMITTENT INCIDENT

Perform 

GI-42, "Intermittent Incident"

.

Is the inspection result normal?

YES

>> Replace IPDM E/R.

NO

>> Repair or replace harness connectors.

Component Inspection (Cooling Fan Motor)

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1.

CHECK COOLING FAN MOTOR

1. Turn ignition switch OFF.

2. Disconnect cooling fan motor harness connector.

Cooling fan motor

Ground

Continuity

Connector

Terminal

E42

(cooling fan relay-2)

6

Ground

Existed

E43

(cooling fan relay-3)

6

Cooling fan motor-2

Ground

Continuity

Connector

Terminal

E221

3

Ground

Existed

4