Diagnostic Procedure: Notes

INSPECTION START
Do you have CONSULT-II?

Yes or No
1. Yes : GO TO 2.
2. No : GO TO 3.
CHECK COOLING FAN MOTOR OPERATION
With CONSULT-II
1. Start engine and let it idle.
2. Select " COOLING FAN" in " ACTIVE TEST" mode with CONSULT-II.
3. Make sure that cooling fan operates.
OK or NG
1. OK : GO TO 4.
2. NG : Check cooling fan control circuit. (Go to "PROCEDURE A ".)
  
  Fig 1: CONSULT II Display - Active Test
  Courtesy of NISSAN MOTOR CO., U.S.A.
CHECK COOLING FAN MOTOR OPERATION
Without CONSULT-II
1. Disconnect engine coolant temperature sensor harness connector.
2. Connect 150Ω resistor to engine coolant temperature sensor harness connector.
3. Start engine and let it idle.
4. Make sure that cooling fan operates.
OK or NG
1. OK : GO TO 4.
2. NG : Check cooling fan control circuit. (Go to "PROCEDURE A ".)
  
  Fig 2: Identifying Cooling Fan Motor Operation
  Courtesy of NISSAN MOTOR CO., U.S.A.
CHECK COOLING SYSTEM FOR LEAK
Apply pressure to the cooling system with a tester, and check if the pressure drops.

Testing pressure: 157 kPa (1.6 kg/cm ² , 23 psi)

CAUTION: Higher than the specified pressure may cause radiator damage. Pressure should not drop.

OK or NG
1. OK : GO TO 5.
2. NG : Check the following for leak. Refer to "CHECKING COOLING SYSTEM FOR LEAKS ".
  - Hose
  - Radiator
  - Radiator cap
  - Water pump
  - Reservoir tank
    
    Fig 3: Identifying Cooling System Leak
    Courtesy of NISSAN MOTOR CO., U.S.A.
CHECK RESERVOIR TANK CAP
Apply pressure to cap with a tester.

Reservoir tank cap relief pressure: 95 - 125 kPa (0.97 - 1.28 kg/cm ² , 14 - 18 psi)

OK or NG
1. OK : GO TO 6.
2. NG : Replace reservoir tank cap.
  
  Fig 4: Identifying Reservoir Tank Cap
  Courtesy of NISSAN MOTOR CO., U.S.A.
CHECK THERMOSTAT
1. Check valve seating condition at normal room temperatures.
  It should seat tightly.
2. Check valve opening temperature and valve lift.
  Valve opening temperature: 82°C (180°F) [standard]
  
  Valve lift: More than 10.0 mm/95°C (0.394 in/203°F)
3. Check if valve is closed at 5°C (9°F) below valve opening temperature.
  For details, Refer to "THERMOSTAT AND WATER PIPING ".
OK or NG
1. OK : GO TO 7.
2. NG : Replace thermostat
  
  Fig 5: Identifying Thermostat
  Courtesy of NISSAN MOTOR CO., U.S.A.
CHECK ENGINE COOLANT TEMPERATURE SENSOR
Refer to "COMPONENT INSPECTION ".

OK or NG
1. OK : GO TO 8.
2. NG : Replace engine coolant temperature sensor.
CHECK MAIN 12 CAUSES
If the cause cannot be isolated, go to "MAIN 12 CAUSES OF OVERHEATING ".
1. : INSPECTION END