Nissan Maxima Service and Repair 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 via the CAN communication line.

SYSTEM DESCRIPTION

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 Operation

Cooling Fan Relay Operation

The ECM controls cooling fan relays in the IPDM E/R via the CAN communication line.

Component Parts Location

1. Intake valve timing control solenoid valve (bank 1)
2. Electronic controlled engine mount control solenoid valve
3. Exhaust valve timing control magnet retarder (bank 2)
4. Intake valve timing control solenoid valve (bank 2)
5. Knock sensor (bank 1 and 2)
6. Fuel injector (bank 2)
7. Ignition coil (with power transistor) and spark plug (bank 2)
8. Exhaust valve timing control position sensor (bank 2)
9. Crankshaft position sensor (POS)
10. Engine coolant temperature sensor
11. Camshaft position sensor (PHASE) (bank 2)
12. Transmission range switch
13. Refrigerant pressure sensor
14. ECM
15. Battery current sensor
16. Condenser-2
17. EVAP canister purge volume control solenoid valve
18. Mass air flow sensor (with intake air temperature sensor)
19. Camshaft position sensor (PHASE) (bank 1)
20. EVAP service port
21. Power valve actuator 2
22. Electric throttle control actuator
23. Exhaust valve timing control position sensor (bank 1)
24. Ignition coil (with power transistor) and spark plug (bank 1)
25. Fuel injector (bank 1)
26. VIAS control solenoid valve 1 and 2
27. Power valve actuator 1
28. Exhaust valve timing control magnet retarder (bank 1)
29. Power steering pressure sensor

1. Mas air flow sensor (with intake air temperature sensor)
2. Air cleaner case
3. Engine coolant temperature sensor (view with engine cover removed)
4. EVAP canister purge volume control solenoid valve (view with engine cover removed)
5. Power valve actuator 1 (view with engine cover removed)
6. VIAS control solenoid valve 1
7. VIAS control solenoid valve 2
8. Power valve actuator 2
9. Power steering pressure sensor
10. Tie rod (RH)
11. Camshaft position sensor (PHASE) (bank 1) (view with air cleaner case removed)
12. Exhaust valve timing control position sensor (bank 1)
13. Camshaft position sensor (PHASE) (bank 2) (view with air cleaner case removed)
14. Exhaust valve timing control position sensor (bank 2)
15. Engine oil temperature sensor
    : Vehicle front

1. A/F sensor 1 (bank 1) (view with engine removed)
2. A/F sensor 1 (bank 2)
3. HO2S2 (bank 1) harness connector (view with engine removed)
4. HO2S2 (bank 2) harness connector
5. Front engine mount
6. Crankshaft position sensor (POS)
   : Vehicle front

1. Electronic controlled engine mount control solenoid valve (view with engine cover removed)
2. EVAP control system pressure sensor (view with rear suspension member removed)
3. EVAP canister vent control valve
4. EVAP canister
5. Fuel injector harness connector (view with intake manifold collector removed)
6. Exhaust valve timing control magnet retarder (bank 1) (view with engine removed)
7. Intake valve timing control solenoid valve (bank 1)
8. Intake valve timing control solenoid valve (bank 2)
9. Exhaust valve timing control magnet retarder (bank 2)
   : Vehicle front

1. Knock sensor (bank 2) (view with intake manifold removed)
2. Knock sensor (bank 1)
3. Transmission range switch (view with CVT removed)
4. Battery
5. IPDM E/R
6. ECM
7. Refrigerant pressure sensor (view with front grille removed)
8. Accelerator pedal position sensor
   : Vehicle front

1. Stop lamp switch
2. ASCD brake switch
3. ASCD steering switch

Component Description

Component Reference

• Camshaft position sensor (PHASE) EC-300, "Description"
• Crankshaft position sensor (POS) EC-296, "Description"
• Cooling fan motor EC-486, "Description"
• Engine coolant temperature sensor EC-201, "Description"
• Refrigerant pressure sensor