Diagnostic Procedure: Notes

INSPECTION START
Do you have CONSULT-II?

Yes or No
1. Yes: GO TO 2.
2. No: GO TO 5.
CHECK COOLING FAN LOW SPEED OPERATION
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.
  
  Fig 1: CONSULT-II ACTIVE TEST Display Screen
  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 ".)
CHECK COOLING FAN MIDDLE SPEED OPERATION
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: CONSULT-II ACTIVE TEST Display Screen
  Courtesy of NISSAN MOTOR CO., U.S.A.
CHECK COOLING FAN HIGH SPEED OPERATION
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: CONSULT-II ACTIVE TEST Display Screen
  Courtesy of NISSAN MOTOR CO., U.S.A.
CHECK COOLING FAN LOW SPEED OPERATION
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: Identifying Cooling Fan Relay (1 Of 2)
  Courtesy of NISSAN MOTOR CO., U.S.A.
  
  Fig 5: Identifying Cooling Fan Relay (2 Of 2)
  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: Checking Cooling Fans-1 And -2 Operate At Low Speed
  Courtesy of NISSAN MOTOR CO., U.S.A.
CHECK COOLING FAN MIDDLE SPEED OPERATION
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: Checking Cooling Fan Middle Speed Operation
  Courtesy of NISSAN MOTOR CO., U.S.A.
CHECK COOLING FAN HIGH SPEED OPERATION
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: Checking Cooling Fan High Speed Operation
  Courtesy of NISSAN MOTOR CO., U.S.A.
CHECK COOLING SYSTEM FOR LEAK
Apply pressure to the cooling system with a tester, and check if the pressure drops.

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

CAUTION: Higher than the specified pressure may cause radiator damage. Pressure should not drop.

Fig 9: Applying Pressure To Cooling System With A Tester
Courtesy of NISSAN MOTOR CO., U.S.A.

OK or NG
1. OK: GO TO 9.
2. NG: Check the following for leak
  - Hose
  - Radiator
  - Water pump
    Refer to "WATER PUMP ".
CHECK RADIATOR CAP
Apply pressure to cap with a tester.

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: Checking Radiator Cap
  Courtesy of NISSAN MOTOR CO., U.S.A.
CHECK COMPONENT PARTS
Check the following.
- Thermostat (Refer to "THERMOSTAT AND WATER CONTROL VALVE ".)
- Water control valve (Refer to "THERMOSTAT AND WATER CONTROL VALVE ".)
- Engine coolant temperature sensor (Refer to "COMPONENT INSPECTION ".)
OK or NG
1. OK: GO TO 11.
2. NG: Replace malfunctioning component.
CHECK MAIN 13 CAUSES
If the cause cannot be isolated, go to "MAIN 13 CAUSES OF OVERHEATING ".
1. : INSPECTION END