2020 Kia Sedona P0598 Coolant Thermostat Heater

2020 Kia Sedona


  • 3.3L V6 Engine
  • Horsepower: Approximately 276 hp
  • Torque: Approximately 248 lb-ft


  • 8-speed automatic transmission

Fuel Economy:

  • The EPA estimated fuel economy is around 18 MPG city and 24 MPG highway.

Understanding and Addressing the P0598 Code in Your 2020 Kia Sedona

Modern vehicles are equipped with sophisticated onboard diagnostic systems that help monitor and maintain their optimal performance. These systems communicate with us through the language of trouble codes, providing valuable insights into potential issues that may arise. Owners of 2020 Kia Sedona models have reported a particular code, P0598, which indicates a concern with the Engine Coolant Thermostat Heater Control Circuit. In this article, we will delve into what this code means, its implications, and the steps to take if you encounter it in your Kia Sedona.

Decoding the P0598 Code:

P0598 is a diagnostic trouble code (DTC) that originates from the OBD-II (On-Board Diagnostics, 2nd Generation) system. This standardized system helps mechanics and technicians pinpoint specific issues within a vehicle’s various systems and components. In the case of the P0598 code on a 2020 Kia Sedona, it signifies a problem related to the Engine Coolant Thermostat Heater Control Circuit.


The Role of the Engine Coolant Thermostat Heater Control Circuit:

The Engine Coolant Thermostat Heater Control Circuit is an integral part of the engine’s cooling system. Its primary purpose is to regulate the flow of coolant through the engine to maintain an optimal operating temperature. For cold weather conditions, certain vehicles like the 2020 Kia Sedona feature an engine coolant thermostat with an integrated electric heater. This heater assists in quickly warming up the engine, which is essential for efficient fuel combustion and reduced emissions during cold starts.

Possible Causes and Symptoms:

When the P0598 code is triggered, it indicates a malfunction within the control circuit of the Engine Coolant Thermostat Heater. Several factors could contribute to this issue:

  • Faulty Thermostat Heater Element: The electric heater within the thermostat may be malfunctioning.

A vehicle’s thermostat plays a crucial role in maintaining optimal engine temperature and overall performance. It remains closed when the engine is cold, allowing it to quickly warm up for efficient combustion. Once the engine reaches the designated temperature, the thermostat opens, permitting coolant circulation to cool down the engine and prevent overheating.

  • Wiring and Connector Issues: Damaged wiring or corroded connectors in the circuit can disrupt the proper flow of electricity.
  • Temperature Sensor Malfunction: A faulty temperature sensor could lead to incorrect signals being sent to the Engine Control Module (ECM).
  • ECM Issues: Problems with the ECM, which manages the engine’s functions, can also trigger this code.

Symptoms associated with the P0598 code might include:

  • Engine operating at temperatures outside the normal range.
  • Reduced fuel efficiency due to improper engine temperature.
  • Illumination of the Check Engine Light (Malfunction Indicator Lamp, or MIL).
  • Slower engine warm-up time in colder weather.

Diagnostic and Repair Process:

If you encounter the P0598 code in your 2020 Kia Sedona, it’s advisable to follow these steps to diagnose and resolve the issue:

  1. Code Retrieval: Use an OBD-II scanner to retrieve the trouble codes and gather additional information about the problem.
  2. Visual Inspection: Inspect the wiring, connectors, and components associated with the thermostat heater circuit for any visible damage.
  3. Thermostat Heater Testing: Test the thermostat heater element’s resistance and functionality.
  4. Temperature Sensor Check: Ensure the temperature sensor is providing accurate readings to the ECM.
  5. ECM Testing: If necessary, evaluate the ECM’s functionality to rule out any internal issues.

Following the diagnosis, you’ll need to repair or replace the faulty component. We suggest consulting an experienced mechanic or technician familiar with Kia vehicles for a correct solution.

In conclusion, the P0598 code on a 2020 Kia Sedona points to a potential issue with the Engine Coolant Thermostat Heater Control Circuit. This vital component contributes to maintaining the engine’s optimal temperature, ensuring efficient performance and reduced emissions. If you’re unsure about performing the repairs yourself, seeking professional assistance of an expert Kia mechanic is recommended.

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