Diagnostic Procedure: Notes

1. Start engine and let id idle.
2. Make sure that cooling fan (crankshaft driven) operates normally.

OK or NG

1. OK (With CONSULT-II): GO TO 2.
2. OK (Without CONSULT-II): GO TO  4 .
3. NG: Check cooling fan (crankshaft driven). Refer to "COOLING FAN ".

With CONSULT-II 

1. Start engine and let it idle.
2. Select "COOLING FAN" in "ACTIVE TEST" mode with CONSULT-II, and touch "MID" on the CONSULT-II screen.
3. Make sure that cooling fan operates.

OK or NG

1. OK: GO TO 3.
2. NG: Check cooling fan middle speed control circuit. (go to "PROCEDURE A  ".)

Fig 1: Displaying Active Test

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

With CONSULT-II 

1. Select "COOLING FAN" in "ACTIVE TEST" mode with CONSULT-II and touch "HI" on the CONSULT-II screen.
2. Make sure that cooling fan operates at higher speed than middle speed.

OK or NG

1. OK: GO TO  6 .
2. NG: Check cooling fan high speed control circuit. (go to "PROCEDURE B  ".)

Fig 2: Displaying Active Test

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

Without CONSULT-II 

1. Disconnect engine coolant temperature sensor harness connector.
2. Connect 200ohm 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 5.
2. NG: Check cooling fan middle speed control circuit. (go to "PROCEDURE A  ".)

Fig 3: Connecting 200ohm Resistor To Engine Coolant Temperature Sensor Harness Connector

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

Without CONSULT-II 

1. Disconnect 200ohm resister to the engine coolant temperature sensor harness connector.
2. Connect 150ohm resistor to engine coolant temperature sensor harness connector.
3. Start engine and let it idle.
4. Make sure that cooling fan operates at higher speed than middle speed.

OK or NG

1. OK: GO TO 6.
2. NG: Check cooling fan control circuit. (go to "PROCEDURE B  ".)

Fig 4: Connecting 150ohm Resistor To Engine Coolant Temperature Sensor Harness Connector

Courtesy of NISSAN MOTOR CO., U.S.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) 

Fig 5: Checking Cooling System For Leak

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

OK or NG

1. OK: GO TO 7.
2. NG: Check the following for leak. Refer to "LEAK CHECK ".
   • Hose
   • Radiator
   • Water pump

Apply pressure to cap with a tester.

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

OK or NG

1. OK: GO TO 8.
2. NG: Replace radiator cap.

Fig 6: Applying Pressure To Cap With A Tester

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.

   For details, refer to "THERMOSTAT AND WATER CONTROL VALVE ".

   Fig 7: Checking Valve Opening Temperature And Valve Lift

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

OK or NG

1. OK: GO TO 9.
2. NG: Replace thermostat

Refer to "COMPONENT INSPECTION  ".

OK or NG

1. OK: GO TO 10.
2. NG: Replace engine coolant temperature sensor.

If the cause cannot be isolated, go to "MAIN 12 CAUSES OF OVERHEATING  ".

1. : INSPECTION END