Diagnostic Procedure: Notes

WARNING: This page is about a different car, the 2004 Nissan Quest. However, it is still accessible from the selected car via links, so may be relevant.

INSPECTION START
Do you have CONSULT-II?

Yes or No
1. Yes: GO TO 2.
2. No: GO TO 3 .
CHECK COOLING FAN 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 fans-1 and -2 operate at each speed (LOW/MID/HI).
OK or NG
1. OK: GO TO 4 .
2. NG: Check cooling fan control circuit. (Go to PROCEDURE A .)
  
  Fig 1: Identifying Active Test Screen
  Courtesy of NISSAN MOTOR CO., U.S.A.
CHECK COOLING FAN OPERATION
Without CONSULT-II
1. Perform "IPDM E/R auto active test" and check cooling fan motors operation, refer to AUTO ACTIVE TEST .
2. Make sure that cooling fans-1 and -2 operate at each speed (Low/Middle/High).
OK or NG
1. OK: GO TO 4.
2. NG: Check cooling fan control circuit. (Go to PROCEDURE 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/cm² , 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
  - Water pump
    
    Fig 2: Checking Cooling System For Leaks
    Courtesy of NISSAN MOTOR CO., U.S.A.
CHECK RADIATOR CAP
Apply pressure to cap with a tester.

Radiator cap relief pressure: 59 - 98 kPa (0.6 - 1.0 kg/cm² , 9 - 14 psi)

OK or NG
1. OK: GO TO 6.
2. NG: Replace radiator cap.
  
  Fig 3: Checking Radiator 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 8.6 mm/95°C (0.339 in/203°F)
3. Check if valve is closed at 5°C (9°F) below valve opening temperature.
  For details, refer to THERMOSTAT AND THERMOSTAT HOUSING .
OK or NG
1. OK: GO TO 7.
2. NG: Replace thermostat
  
  Fig 4: Checking Valve Seating Condition At Normal Room Temperatures
  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