Diagnostic Procedure: Notes

WARNING: This page is about a different car, the 2004 Nissan Titan. 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 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
  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 ohm 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: Checking 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.
1. 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 cooling system for leaks. .
  - Hose
  - Radiator
  - Water pump
  Fig 3: Checking Cooling System For Leak
  Courtesy of NISSAN MOTOR CO., U.S.A.
CHECK RADIATOR CAP
Apply pressure to cap with a tester.
1. Radiator cap relief pressure: 59 - 98 kPa (0.6 - 1.0 kg/cm ², 9 - 14 psi)
OK or NG
1. OK: GO TO 6.
2. NG: Replace radiator cap.
Fig 4: 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.
  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.
  For details, refer to THERMOSTAT AND WATER PIPING in ENGINE COOLING SYSTEM - TITAN article.
  
  OK or NG
  1. OK: GO TO 7.
  2. NG: Replace thermostat
  Fig 5: Checking 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