Diagnostic Procedure

Do you have CONSULT-II?

Yes or No

1. Yes: GO TO 2.
2. No: GO TO  4.

With CONSULT-II 

1. Start engine and let it idle.
2. Select "COOLING FAN" in "ACTIVE TEST" mode with CONSULT-II and touch "LOW" on the CONSULT-II screen.
3. Make sure that cooling fans-1 and -2 operate at low speed.

OK or NG

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

Fig 1: CONSULT-II Active Test Display

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

With CONSULT-II 

1. Touch "HIGH" on the CONSULT-II screen.
2. Make sure that cooling fans-1 and -2 operate at higher speed than low speed.

OK or NG

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

Fig 2: CONSULT-II Active Test Display

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

Without CONSULT-II 

1. Start engine and let it idle.
2. Turn air conditioner switch ON.
3. Turn blower fan switch ON.
4. Make sure that cooling fans-1 and -2 operate at low speed.

OK or NG

1. OK: GO TO 5.
2. NG: Check cooling fan low speed control circuit. (Go to PROCEDURE A .)

Fig 3: Operating Cooling Fan On Low Speed

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

Without CONSULT-II 

1. Turn ignition switch OFF.
2. Turn air conditioner switch and blower fan switch OFF.
3. Disconnect engine coolant temperature sensor harness connector.
4. Connect 150Ω resistor to engine coolant temperature sensor harness connector.
5. Restart engine and make sure that cooling fans-1 and -2 operate at higher speed than low speed.

OK or NG

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

Fig 4: Operating Cooling Fan On Low Speed

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) 

OK or NG

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

Fig 5: Applying Pressure To Cooling System With Tester

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

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 8.
2. NG: Replace radiator cap.

Fig 6: Applying Pressure To Radiator Cap With 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: 76.5°C (170°F) [standard] 
   2. 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 7: Heating Thermostat Valve

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