Scan Tool Testing and Procedures
Cooling System Operation:
COOLING FAN CONTROL
The ECM controls the cooling fan corresponding to the signals sent from the vehicle speed and engine coolant temperature. The control system has 2-step control [ON/OFF].
CONSULT REFERENCE VALUE IN DATA MONITOR MODE
Specification data are reference values.
Terminal 36:
ECM TERMINALS AND REFERENCE VALUE
Specification data are reference values and are measured between each terminal and 32 (ECM ground).
ON BOARD DIAGNOSIS LOGIC
If the cooling fan or another component in the cooling system malfunctions, engine coolant temperature will rise. When the engine coolant temperature reaches an abnormally high temperature condition, a malfunction is indicated.
CAUTION: When a malfunction is indicated, be sure to replace the coolant following the procedure in the"Changing Engine Coolant", "ENGINE MAINTENANCE". Also, replace the engine oil.
1. Fill radiator with coolant up to specified level with a filling speed of 2 liters per minute like pouring coolant by kettle. Be sure to use coolant with the proper mixture ratio. Refer to "Anti-freeze Coolant Mixture Ratio", "RECOMMENDED FLUIDS AND LUBRICANTS".
2. After refilling coolant, run engine to ensure that no water-flow noise is emitted.
OVERALL FUNCTION CHECK
Use this procedure to check the overall function of the cooling fan. During this check, a DTC might not be confirmed.
WARNING:
- NEVER REMOVE THE RADIATOR CAP WHEN THE ENGINE IS HOT. SERIOUS BURNS COULD BE CAUSED BY HIGH PRESSURE FLUID ESCAPING FROM THE RADIATOR.
- WRAP A THICK CLOTH AROUND CAP. CAREFULLY REMOVE THE CAP BY TURNING IT A QUARTER TURN TO ALLOW BUILT-UP PRESSURE TO ESCAPE. THEN TURN THE CAP ALL THE WAY OFF.
With Consult
1. Check the coolant level in the reservoir tank and radiator. Allow engine to cool before checking coolant level. If the coolant level in the reservoir tank and/or radiator is below the proper range, skip the following steps and go to "Diagnostic Procedure".
2. Confirm whether customer filled the coolant or not. If customer filled the coolant, skip the following steps and go to "Diagnostic Procedure".
3. Turn ignition switch "ON".
4. Perform "COOLING FAN" in "ACTIVE TEST" mode with CONSULT.
5. Make sure that cooling fan operates.
6. If NG, go to "Diagnostic Procedure".
Without Consult
1. Check the coolant level in the reservoir tank and radiator. Allow engine to cool before checking coolant level. If the coolant level in the reservoir tank and/or radiator is below the proper range, skip the following steps and go to "Diagnostic Procedure".
2. Confirm whether customer filled the coolant or not. If customer filled the coolant, skip the following steps and go to "Diagnostic Procedure".
3. Turn ignition switch "OFF".
4. Disconnect engine coolant temperature sensor harness connector.
5. Connect 150 Ohm resistor to engine coolant temperature sensor harness connector.
6. Start engine and make sure that cooling fan operates.
Be careful not to overheat engine.
7. If NG, go to "Diagnostic Procedure".
WIRING DIAGRAM
DIAGNOSTIC PROCEDURE
MAIN 12 CAUSES OF OVERHEATING
COMPONENT INSPECTION
COOLING FAN RELAY
Check continuity between terminals 3 and 5.
If NG, replace relay.
COOLING FAN MOTOR
1. Disconnect cooling fan motor harness connector.
2. Supply cooling fan motor terminals with battery voltage and check operation.
Cooling fan motor should operate.
If NG, replace cooling fan motor.