Scan Tool Testing and Procedures

ON BOARD DIAGNOSIS LOGIC
If the cooling fan or another component in the cooling system malfunctions, the 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.

a. 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 "Antifreeze Coolant Mixture Ratio", "RECOMMENDED FLUIDS AND LUBRICANTS".
b. After refilling coolant, run engine to ensure that no water flow noise is emitted.





OVERALL FUNCTION CHECK

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.
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".





DIAGNOSTIC PROCEDURE
Perform FINAL CHECK by the following procedure after repair is completed.
1. Warm up engine. Run the vehicle for at least 20 minutes. Pay attention to engine coolant temperature gauge on the instrument panel. If the reading shows an abnormally high temperature, another part may be malfunctioning.
2. Stop vehicle and let engine idle. Check the intake and exhaust systems for leaks by listening for noise or visually inspecting the components.
3. Allow engine to cool and visually check for oil and coolant leaks. Then, perform "OVERALL FUNCTION CHECK".





MAIN 12 CAUSES OF OVERHEATING
For more information, refer to "OVERHEATING CAUSE ANALYSIS".