Diagnostic Procedure: Notes

INSPECTION START
Do you have CONSULT-II?

Yes or No

Yes: GO TO 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

OK: GO TO 4.

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 150° 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

OK: GO TO 4.

NG: Check cooling fan control circuit. (Go to "PROCEDURE A ".)

Fig 2: Connecting 150° Resistor To Engine Coolant Temperature Sensor Harness Connector
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

OK: GO TO 5.

NG: Check the following for leak. Refer to "CHECKING COOLING SYSTEM FOR LEAKS ".

Fig 3: Checking Cooling System Leakage
Courtesy of NISSAN MOTOR CO., U.S.A.
- Hose
- Radiator
- Radiator cap
- Water pump
- Reservoir tank
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

OK: GO TO 6.

NG: Replace reservoir tank cap.

Fig 4: Checking 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

OK: GO TO 7.

NG: Replace thermostat

Fig 5: Checking Thermostat Valve Opening Temperature And Valve Lift
Courtesy of NISSAN MOTOR CO., U.S.A.
CHECK ENGINE COOLANT TEMPERATURE SENSOR
Refer to "COMPONENT INSPECTION ".

OK or NG

OK: GO TO 8.

NG: Replace engine coolant temperature sensor.
CHECK MAIN 12 CAUSES
If the cause cannot be isolated, go to "MAIN 12 CAUSES OF OVER HEATING ".

: INSPECTION END