Nissan Altima (L32) 2007-2012 Service Manual: Cooling fan control

System Diagram

System Description

INPUT/OUTPUT SIGNAL CHART

*1: The ECM determines the start signal status by the signals of engine speed and battery voltage.

*2: This signal is sent to ECM through CAN communication line.

SYSTEM DESCRIPTION

ECM controls cooling fan speed corresponding to vehicle speed, engine coolant temperature, refrigerant pressure, air conditioner ON signal. Then control system has 4-step control [HIGH/MIDDLE/LOW/OFF].

Cooling Fan Operation

Cooling Fan Relay Operation

The ECM controls cooling fan relays through CAN communication line.

Component Parts Location

1. Intake valve timing control solenoid valve

2. Ignition coil (with power transistor) and spark plug

3. Knock sensor, Crankshaft position sensor (POS)

4. Air fuel ratio (A/F) sensor 1

5. Camshaft position sensor (PHASE)

6. Engine coolant temperature sensor

7. Park/neutral position (PNP) switch

8. ECM

9. Refrigerant pressure sensor

10. Battery current sensor

11. IPDM E/R

12. Mass air flow sensor (with intake temperature sensor)

13. EVAP service port

14. Electric throttle control actuator (with built in throttle position sensor and throttle control motor)

15. EVAP canister purge volume control solenoid valve

16. Fuel injector

17. Power steering pressure sensor

1. Battery

2. Fuel pump fuse (15A)

3. IPDM E/R

4. Brake master cylinder

5. Engine ground

6. Air cleaner assembly

7. Mass air flow sensor (with intake air temperature sensor)

8. Radiator hose (upper)

9. Engine coolant temperature sensor

10. Intake air duct

11. Camshaft position sensor (PHASE)

12. Tie rod (RH)

13. Power steering pressure sensor

14. Knock sensor

15. Engine oil cooler

16. Crankshaft position sensor (POS)

17. Drive shaft (RH)

1. Exhaust manifold cover

2. Air fuel ratio (A/F) sensor 1

3. Heated oxygen sensor 2 (This illustration is a view from under vehicle.)

4. Engine oil pan

1. EVAP service port

2. Intake air duct

3. EVAP canister purge volume control solenoid valve

4. Intake manifold collector

5. Park/neutral position (PNP) switch (CVT) (This illustration is view with air cleaner assembly removed.)

6. Park/neutral position (PNP) switch (M/T) (This illustration is view with air cleaner assembly removed.)

7. Intake valve timing control solenoid valve (This illustration is view with engine removed.)

8. Exhaust manifold cover

9. Air fuel ratio (A/F) sensor 1

10. Air fuel ratio (A/F) sensor 1 harness connector

11. Heated oxygen sensor 2 (This illustration is view from under vehicle.)

12. Heated oxygen sensor 2 harness connector (This illustration is view from under vehicle.)

13. Engine oil pan

1. Throttle valve (This illustration is view with intake air duct removed.)

2. Electric throttle control actuator

3. Fuel injector harness connector

4. Condenser-2

5. Radiator hose (upper)

6. Battery

7. ECM

8. Fuel level sensor unit and fuel pump harness connector (This illustration is view with rear seat cushion and inspection hole cover removed.)

9. Fuel level sensor unit and fuel pump assembly

10. Fuel pressure regulator

11. Fuel tank temperature sensor

12. EVAP control system pressure sensor (This illustration is view with rear suspension member removed.)

13. EVAP canister vent control valve (This illustration is view with rear suspension member removed.)

14. EVAP canister (This illustration is view with rear suspension member removed.)

1. No.1 ignition coil

2. Cooling fan motor-1 harness connector

3. Cooling fan motor-2 harness connector

4. Refrigerant pressure sensor

5. Accelerator pedal position sensor

6. ASCD brake switch

7. Stop lamp switch

8. Brake pedal

9. ASCD clutch switch

10. Clutch pedal

11. ASCD steering switch

12. CANSEC switch

13. RESUME/ACCELERATE switch

14. SET/COAST switch

15. MAIN switch

Component Description