Diagnostic Procedure: Notes

Do you have CONSULT-II?

Yes or No 

1. Yes : GO TO 2.
2. No : GO TO  4.

With CONSULT-II 

1. Turn ignition switch ON.
2. Perform "COOLING FAN" in "ACTIVE TEST" mode with CONSULT-II and touch "LOW" on the CONSULT-II screen.
   Fig 1: ACTIVE TEST, COOLING FAN - CONSULT-II Display Screen

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

With CONSULT-II 

1. Touch "HI" on the CONSULT-II screen.
   Fig 2: ACTIVE TEST, COOLING FAN - CONSULT-II Display Screen

   Courtesy of NISSAN MOTOR CO., U.S.A.
2. Make sure that cooling fans-1 and -2 operates at high speed.

OK or NG 

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

Without CONSULT-II 

1. Turn ignition switch OFF.
2. Disconnect cooling fan relay-2 and relay-3.
   Fig 3: Locating Cooling Fan Relay 2 And Relay 3

   Courtesy of NISSAN MOTOR CO., U.S.A.
3. Start engine and let it idle.
4. Set temperature lever at full cold position.
5. Turn air conditioner switch ON.
6. Turn blower fan switch ON.
7. Make sure that cooling fans-1 and -2 operate at low speed.
Fig 4: Checking Cooling Fans 1 And 2 Operation At Low Speed
Courtesy of NISSAN MOTOR CO., U.S.A.

OK or NG 

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

Without CONSULT-II 

1. Turn ignition switch OFF.
2. Reconnect cooling fan relay-2 and relay-3.
3. Turn air conditioner switch and blower fan switch OFF.
4. Disconnect engine coolant temperature sensor harness connector.
5. Connect 150Ω resistor to engine coolant temperature sensor harness connector.
   Fig 5: Connecting 150 Ohm Resistor To Engine Coolant Temperature Sensor Harness Connector

   Courtesy of NISSAN MOTOR CO., U.S.A.
6. Restart engine and make sure that cooling fans-1 and -2 operates at high speed.

OK or NG 

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

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 6: Pressure Testing Cooling System For Leaks

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

OK or NG 

1. OK : GO TO  8.
2. NG : GO TO 7.

Check the following for leak.

• Hose
• Radiator
• Water pump (Refer to WATER PUMP .)
  1. : Repair or replace.

Apply pressure to cap with a tester.

1. Radiator cap relief pressure: 
   1. 59 - 98 kPa (0.6 - 1.0 kg/cm ²  , 9 - 14 psi) 
   Fig 7: Pressure Testing Radiator Cap

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

OK or NG 

1. OK : GO TO 9.
2. NG : Replace radiator cap.

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: 
      1. 82°C (180°F) [standard] 
   2. Valve lift: 
      1. More than 8 mm/95°C (0.31 in/203°F) 
   Fig 8: Checking Thermostat Valve Opening Temperature And Valve Lift
   Courtesy of NISSAN MOTOR CO., U.S.A.
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 10.
2. NG : Replace thermostat.

Refer to "COMPONENT INSPECTION ".

OK or NG 

1. OK : GO TO 11.
2. NG : Replace engine coolant temperature sensor.

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

1. : INSPECTION END