Diagnostic Procedure: Notes

Do you have CONSULT-II?

Yes or No 

1. Yes >> GO TO  2.
2. No >> GO TO  3.

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  ).

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  ).

Apply pressure to the cooling system with a tester, and check if the pressure drops.

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

OK or NG 

1. OK >> GO TO  5.
2. NG >> Check the following for leak.
   • Hose
   • Radiator
   • Water pump
     Fig 1: View Of Cooling System Pressure Tester

     Courtesy of NISSAN MOTOR CO., U.S.A.

Apply pressure to cap with a tester.

1. Radiator cap relief 59 - 98 kPa (0.6 - 1.0 kg/cm ²
2. pressure: 9 - 14 psi) 

OK or NG 

1. OK >> GO TO  6.
2. NG >> Replace radiator cap.
   Fig 2: Checking Radiator Cap

   Courtesy of NISSAN MOTOR CO., U.S.A.

1. Check valve seating condition at normal room temperatures.

   It should seat tightly. 

2. Check valve opening temperature and valve lift.
   1. Valve opening temperature: 82°C (180°F) [standard] 
   2. 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.

OK or NG 

1. OK >> GO TO  7.
2. NG >> Replace thermostat
   Fig 3: Checking Thermostat Operation

   Courtesy of NISSAN MOTOR CO., U.S.A.

Refer to Component Inspection .

OK or NG 

1. OK >> GO TO  8.
2. NG >> Replace engine coolant temperature sensor.

If the cause cannot be isolated, go to Main 12 Causes of Overheating  .

1. >> INSPECTION END