Hyundai Ioniq (AE): Cooling System / Thermostat. Troubleshooting

Troubleshooting
Symptoms
Possible Causes
Remedy
Coolant leakage
•
From the thermostat gasket
Check the mounting bolts
•
Check the torque of the mounting bolts
•
Retighten the bolts and check leakage again.
Check the gasket for damage
•
Check gasket or seal for damage
•
Replace gaskets and reuse the thermostat.
Cooled excessively
•
Low heater performance (cool air blowed-out)
•
Thermogauge indicates 'LOW'
Visually check after removing the radiator cap.
•
Insufficient coolant or leakage.
•
After refilling coolant, recheck.
GDS check&Starting engine
•
Check DTCs
•
Check connection of the fan clutch or the fan motor.
※ If the fan clutch is always connected, there will be a noise at idle.
•
Check the engine coolant sensor, wiring and connectors.
•
Replace the componants.
Remove the thermostat and inspect
•
Check if there are dusts or chips in the thermostat valve.
•
Check adherence of the thermostat.
•
Clean the thermostat valve and reuse the thermostat.
•
Replace the thermostat, if it doesn't work properly.
Heated excessively
•
Engine overheated
•
Thermogauge indicates 'HI'
Visually check after removing the radiator cap.
•
Insufficient coolant or leakage.
※ Be careful when removing a radiator cap of the overheated vehicle.
•
Check air in cooling system.
•
After refilling coolant, recheck.
•
Check the cylinder head gaskets for damage and the tightening torque of the mounting bolts.
GDS check&Starting engine
•
Check DTCs
•
Check the fan motor performance as temperature varies.
•
Check if the fan clutch slips.
•
Check the water pump adherence or impeller damaged.
•
Check the engine coolant sensor, wiring and connectors.
•
Check the fan motor, the relay and the connector.
•
Replace the fan clutch, if it doesn't work properly.
•
Replace the water pump, if it doesn't work properly.
Immerse the thermostat in boiling water and inspection.
•
After removing the thermostat, check it works properly.
※ Check the thermostat opens at the valve opening temperature.
•
Replace the thermostat, if it doesn't work properly.

    Removal and Installation    â€¢ Disassembly of the thermostat would have an adverse effect, causing a lowering of cooling efficiency.

    Other information:

    Hyundai Ioniq (AE) 2017-2022 Service & Repair Manual: Ambient Temperature Sensor. Description and operation

    DescriptionThe ambient temperature sensor is located at the front of the condenser and detects ambient air temperature. It is a negative type thermistor; resistance will increase with lower temperature, and decrease with higher temperature.The sensor output will be used for discharge temperature control, temperature regulation door contrl, blower m

    Hyundai Ioniq (AE) 2017-2022 Service & Repair Manual: High voltage shut-off procedures

    High Voltage Shut-off Procedures    â€¢ Be sure to read and follow the "General Safety Information and Caution" before doing any work related with the high voltage system. Failure to follow the safety instructions may result in serious electrical injuries.

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