Diagnostic Procedure: Notes

1. Start engine and let id idle.
2. Make sure that cooling fan (crankshaft driven) operates normally.

OK or NG 

OK (With CONSULT-III)>>GO TO  2.

OK (Without CONSULT-III)>>GO TO  4.

NG: Check cooling fan (crankshaft driven). Refer to "COOLING FAN ".

With CONSULT-III 

1. Start engine and let it idle.
2. Select "COOLING FAN" in "ACTIVE TEST" mode with CONSULT-III, and touch "MID" on the CONSULT-III screen.
3. Make sure that cooling fan operates.

OK or NG 

OK: GO TO  3.

NG: Check cooling fan middle speed control circuit. (Go to "PROCEDURE A ".)

With CONSULT-III 

1. Select "COOLING FAN" in "ACTIVE TEST" mode with CONSULT-III and touch "HI" on the CONSULT-III screen.
2. Make sure that cooling fan operates at higher speed than middle speed.

OK or NG 

OK: GO TO  6.

NG: Check cooling fan high speed control circuit. (Go to "PROCEDURE B ".)

Without CONSULT-III 

1. Disconnect engine coolant temperature sensor harness connector.
2. Connect 200Ω resistor to engine coolant temperature sensor harness connector.
3. Start engine and let it idle.
4. Make sure that cooling fan operates.

OK or NG 

OK: GO TO  5.

NG: Check cooling fan middle speed control circuit. (Go to "PROCEDURE A ".)

Fig 1: Connecting 200Ω Resistor To Engine Coolant Temperature Sensor Harness Connector

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

Without CONSULT-III 

1. Disconnect 200Ω resister to the engine coolant temperature sensor harness connector.
2. Connect 150Ω resistor to engine coolant temperature sensor harness connector.
3. Start engine and let it idle.
4. Make sure that cooling fan operates at higher speed than middle speed.

OK or NG 

OK: GO TO  6.

NG: Check cooling fan control circuit. (Go to "PROCEDURE B ".)

Fig 2: 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.

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

OK or NG 

OK: GO TO  7.

NG: Check the following for leak. Refer to "LEAK CHECK ".

• Hose
• Radiator
• Water pump

Fig 3: Checking Cooling System For Leak

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

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 

OK: GO TO  8.

NG: Replace radiator cap.

Fig 4: Applying Pressure To Cap With Tester

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

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 

OK: GO TO  9.

NG: Replace malfunctioning component.

If the cause cannot be isolated, go to "MAIN 13 CAUSES OF OVERHEATING ".

>> INSPECTION END