Diagnostic Procedure: Notes

INSPECTION START
Do you have CONSULT-II?

Yes or No

Yes: GO TO 2.

No: GO TO 4.
CHECK COOLING FAN LOW SPEED OPERATION
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.
3. Make sure that cooling fans-1 and -2 operates at low speed.
Fig 1: Generic Scan Tool - Active Test
Courtesy of NISSAN MOTOR CO., U.S.A.

OK or NG

OK: GO TO 3.

NG: Check cooling fan low speed control circuit. (Go to "PROCEDURE A ".)
CHECK COOLING FAN HIGH SPEED OPERATION
With CONSULT-II
1. Touch "HI" on the CONSULT-II screen.
2. Make sure that cooling fans-1 and -2 operates at higher speed than low speed.
Fig 2: Generic Scan Tool - Active Test
Courtesy of NISSAN MOTOR CO., U.S.A.

OK or NG

OK: GO TO 6.

NG: Check cooling fan high speed control circuit. (Go to "PROCEDURE B ".)
CHECK COOLING FAN LOW SPEED OPERATION
Without CONSULT-II
1. Turn ignition switch OFF.
2. Disconnect cooling fan relay-3.
  
  Fig 3: Identifying Throttle Control Motor Relay And Cooling Fan Relay
  Courtesy of NISSAN MOTOR CO., U.S.A.
3. Start engine and let it idle.
4. Turn air conditioner switch ON.
5. Turn blower fan switch ON.
6. Make sure that cooling fans-1 and -2 operates at low speed.
Fig 4: Identifying Cooling Fan
Courtesy of NISSAN MOTOR CO., U.S.A.

OK or NG

OK: GO TO 5.

NG: Check cooling fan low speed control circuit. (Go to "PROCEDURE A ".)
CHECK COOLING FAN HIGH SPEED OPERATION
Without CONSULT-II
1. Turn air conditioner switch and blower fan switch OFF.
2. Stop engine and turn ignition switch OFF.
3. Reconnect cooling fan relay-3.
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 fans-1 and -2 operates at higher speed than low speed.
Fig 5: Identifying Cooling Fan And Engine Coolant Temperature Sensor Harness Connector
Courtesy of NISSAN MOTOR CO., U.S.A.

OK or NG

OK: GO TO 6.

NG: Check cooling fan high speed control circuit. (Go to "PROCEDURE B ".)
CHECK COOLING SYSTEM FOR LEAK
Apply pressure to the cooling system with a tester, and check if the pressure drops.

Testing pressure: 157 kPa (1.57 bar, 1.6 kg/cm ² , 23 psi)

CAUTION: Higher than the specified pressure may cause radiator damage.

Pressure should not drop.

Fig 6: Applying Pressure To Cooling System With Tester
Courtesy of NISSAN MOTOR CO., U.S.A.

OK or NG

OK: GO TO 9.

NG: GO TO 8.
DETECT MALFUNCTIONING PART
Check the following for leak.
- Hose
- Radiator
- Water pump (Refer to "WATER PUMP ".)
  Repair or replace.
CHECK RADIATOR CAP
Apply pressure to cap with a tester and check radiator cap relief pressure.

Radiator cap relief pressure: 59 - 98 kPa (0.59 - 0.98 bar, 0.6 - 1.0 kg/cm ² , 9 - 14 psi)

Fig 7: Checking Radiator Cap Relief Pressure
Courtesy of NISSAN MOTOR CO., U.S.A.

OK or NG

OK: GO TO 11.

NG: Replace radiator cap.
CHECK THERMOSTAT
1. Remove thermostat.
2. Check valve seating condition at normal room temperatures.
  It should seat tightly.
3. 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)
  
  Fig 8: Checking Valve Opening Temperature And Valve Lift
  Courtesy of NISSAN MOTOR CO., U.S.A.
4. Check if valve is closed at 5°C (9°F) below valve opening temperature.
  For details, refer to "THERMOSTAT AND WATER CONTROL VALVE "
  
  OK or NG
  
  OK: GO TO 12.
  
  NG: Replace thermostat.
CHECK ENGINE COOLANT TEMPERATURE SENSOR
Refer to "COMPONENT INSPECTION ".

OK or NG

OK: GO TO 13.

NG: Replace engine coolant temperature sensor.
CHECK MAIN 12 CAUSES
If the cause cannot be isolated, go to "MAIN 12 CAUSES OF OVERHEATING ".

INSPECTION END