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. Disconnect cooling fan relay-2 and relay-3.
2. Turn ignition switch ON.
   Fig 1: Disconnecting Cooling Fan Relay-2 & Relay-3

   Courtesy of NISSAN MOTOR CO., U.S.A.
3. Perform "COOLING FAN" in "ACTIVE TEST" mode with CONSULT-II.
4. Make sure that cooling fans-1 and -2 operate at low speed.
   Fig 2: Displaying ACTIVE TEST Mode With Consult-II

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

OK or NG 

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

WITH CONSULT-II 

1. Turn ignition switch OFF.
2. Reconnect cooling fan relay-2 and relay-3.
3. Turn ignition switch ON.
4. Perform "COOLING FAN" in "ACTIVE TEST" mode with CONSULT-II.
5. Make sure that cooling fan-1 operates at high speed.
   Fig 3: Displaying ACTIVE TEST Mode With Consult-II

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

OK or NG 

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

Without CONSULT-II 

1. Disconnect cooling fan relay-2 and relay-3.
2. Start engine and let it idle.
3. Set temperature lever at full cold position.
4. Turn air conditioner switch ON.
5. Turn blower fan switch ON.
   Fig 4: Disconnecting Cooling Fan Relay-2 & Relay-3

   Courtesy of NISSAN MOTOR CO., U.S.A.
6. Make sure that cooling fans-1 and -2 operate at low speed.
Fig 5: Checking Cooling Fan Operation
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 .)

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.
6. Restart engine and make sure that cooling fan-1 operates at high speed.
   Fig 6: Connecting Resistor To Engine Coolant Temperature Sensor Harness Connector

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

OK or NG 

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

Apply pressure to the cooling system with a tester, and check if the pressure drops.

Testing pressure: 157 kPa (1.6 kg/cm2, 23 psi) 

OK or NG 

1. OK: GO TO  8.
2. NG: GO TO 7.

Fig 7: Applying Pressure To Cooling System With Tester

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

Check the following for leak.

• Hose
• Radiator
• Water pump (Refer to "WATER PUMP ".)

  Repair or replace.

Apply pressure to cap with a tester.

Radiator cap relief pressure: 

59 - 98 kPa (0.6 - 1.0 kg/cm2, 9 - 14 psi) 

Fig 8: Checking 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.

   Valve opening temperature: 

   82°C (180°F) [standard] 

   Valve lift: 

   More than 8 mm/95°C (0.31 in/203°F) 

3. Check if valve is closed at 5°C (9°F) below valve opening temperature.
   Fig 9: Checking Thermostat

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

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