Diagnostic Procedure: Notes

Do you have CONSULT-II?

Yes or No 

1. Yes: GO TO 2.
2. No: GO TO 5.

With CONSULT-II 

1. Start engine and let it idle.
2. Perform "COOLING FAN" in "ACTIVE TEST" mode with CONSULT-II and touch "LOW" on the CONSULT-II screen.
   CAUTION: Never change cooling fan speed from "LOW" to "HI" or from "HI" to "LOW" directly. Change the speed through "MID" to prevent cooling fan motor from damage.
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: Display Cooling Fan In Active Test Mode

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

With CONSULT-II 

1. Perform "COOLING FAN" in "ACTIVE TEST" mode with CONSULT-II and touch "MID" 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 4.
2. NG: Check cooling fan middle speed control circuit. (Go to "PROCEDURE B ".)

Fig 2: Display Active Test Mode

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

With CONSULT-II 

1. Perform "COOLING FAN" in "ACTIVE TEST" mode with CONSULT-II and touch "HI" on the CONSULT-II screen.
   CAUTION: Never change cooling fan speed from "LOW" to "HI" or from "HI" to "LOW" directly. Change the speed through "MID" to prevent cooling fan motor from damage.
2. Make sure that cooling fan-2 operates at higher speed than middle speed.

OK or NG 

1. OK: GO TO 8.
2. NG: Check cooling fan high speed control circuit. (Go to "PROCEDURE C ".)

Fig 3: Display Active Test Mode

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

Without CONSULT-II 

1. Turn ignition switch ON.
2. Disconnect cooling fan relay-1 and -3.
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.
   Fig 4: Locating Cooling Fan Relay-1

   Courtesy of NISSAN MOTOR CO., U.S.A.
   Fig 5: Locating Cooling Fan Relay-3

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

OK or NG 

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

Fig 6: Identifying Cooling Fan And Its Operating Conditions

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

Without CONSULT-II 

1. Turn ignition switch OFF.
2. Reconnect cooling fan relay-1 and disconnect cooling fan relay-2.
3. Disconnect engine coolant temperature sensor harness connector.
4. Connect 200Ω 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 7.
2. NG: Check cooling fan middle speed control circuit. (Go to "PROCEDURE B ".)

Fig 7: Connecting 200Ω Resistor To Engine Coolant Temperature Sensor Harness Connector

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

Without CONSULT-II 

1. Turn ignition switch OFF.
2. Reconnect cooling fan relay-3.
3. Turn air conditioner switch and blower fan switch OFF.
4. Disconnect 200Ω resistor then connect 150Ω resistor to engine coolant temperature sensor harness connector.
5. Restart engine and make sure that cooling fan-2 operates at higher speed than middle speed.

OK or NG 

1. OK: GO TO 8.
2. NG: Check cooling fan high speed control circuit. (Go to "PROCEDURE C ".)

Fig 8: Connecting 150Ω 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) 

OK or NG 

1. OK: GO TO 9.
2. NG: Check the following for leak
   • Hose
   • Radiator
   • Water pump

     Refer to "WATER PUMP ".

Fig 9: 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 10.
2. NG: Replace radiator cap.

Fig 10: Applying Pressure To 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: 82°C (180°F) [standard] 
   2. Valve lift: More than 10 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 11: Checking Thermostat

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

OK or NG 

1. OK: GO TO 11.
2. NG: Replace thermostat

Refer to "COMPONENT INSPECTION ".

OK or NG 

1. OK: GO TO 12.
2. NG: Replace engine coolant temperature sensor.

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

1. INSPECTION END