Diagnostic Procedure: Notes

CHECK COOLING FAN (CRANKSHAFT DRIVEN) OPERATION
1. Start engine and let it idle.
2. Make sure that cooling fan (crankshaft driven) operates normally.
OK or NG
- OK (With CONSULT-II): GO TO 2.
- OK (Without CONSULT-II): GO TO 3.
- NG: Check cooling fan (crankshaft driven). Refer to REMOVAL AND INSTALLATION (CRANKSHAFT DRIVEN TYPE) .
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.
  
  Fig 1: CONSULT-II Display - Active Test Mode
  Courtesy of NISSAN MOTOR CO., U.S.A.
3. Make sure that cooling fan operate at each speed (LOW/HI).
OK or NG
- OK: GO TO 4.
- NG: Check cooling fan control circuit. (Go to , "PROCEDURE 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 fan operate at each speed (Low/High).
OK or NG
- OK: GO TO 4.
- 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/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 .
  - Hose
  - Radiator
  - Water pump
Fig 2: Pressure Testing Cooling System For Leakage
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/cm ² , 9 - 14 psi)
OK or NG
- OK: GO TO 6.
- NG: Replace radiator cap.
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: 76.5°C (170°F) [standard]
  - Valve lift: More than 8.6 mm/90°C (0.339 in/194°F)
3. Check if valve is closed at 5°C (9°F) below valve opening temperature.
  For details, refer to WATER INLET AND THERMOSTAT ASSEMBLY .
  
  Fig 4: Checking Thermostat Valve Opening Temperature And Valve Lift
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
- OK: GO TO 7.
- NG: Replace thermostat
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 OVERHEATING .
- : INSPECTION END