P0198 Code Full Analysis: From Meaning to Solution

OBD2 (second generation onboard diagnostic system) plays a vital role in modern car diagnosis. It can detect and report potential faults in real time by monitoring various systems of the vehicle. Among them, P0198 code is a common one in the OBD2 system. This article will explore the meaning, possible causes, symptoms, triggering models, severity, solutions, diagnostic methods, repair costs, removal methods and preventive measures of P0198 code.

1. Meaning of P0198 code

P0198 code stands for "Engine Oil Temperature Sensor Circuit High". In the OBD2 system, each fault code consists of a letter and four digits and has a specific meaning. Among them, "P" stands for powertrain-related faults, "01" means that the fault category belongs to the fuel and air metering or injection control system, and "98" is a specific fault code, indicating that the circuit voltage of the oil temperature sensor is abnormally high.

2. Possible causes of the P0198 code

The occurrence of the P0198 code is usually related to the oil temperature sensor and its related circuits. Possible causes include:

• Oil temperature sensor failure: The sensor may not be able to accurately measure the oil temperature due to aging, damage or contamination, resulting in the output of an erroneous voltage signal.
• Circuit problem: The circuit connected to the sensor may have problems such as open circuit, short circuit, excessive resistance or poor contact, affecting the transmission of the voltage signal.
• Electronic control unit (ECU) failure: Although less common, internal ECU failures may also cause false alarms of the P0198 code.

3. Common symptoms of the P0198 code

When the vehicle has the P0198 code, it may exhibit the following symptoms:

• Check engine light illuminated: The OBD2 system will detect the fault and illuminate the check engine light on the dashboard.
• Degraded engine performance: A faulty oil temperature sensor may affect the cooling and lubrication of the engine, which in turn affects performance.
• Increased fuel consumption: Incorrect oil temperature may cause the engine to run less efficiently, resulting in increased fuel consumption.
• Possible starting difficulties: In extreme cases, if the oil temperature is too high or too low, it may affect the engine starting.

4. Which vehicles can trigger the P0198 code?

The P0198 code applies to all vehicles equipped with the OBD2 system, regardless of brand, model or year. As long as the vehicle is equipped with an oil temperature sensor and the sensor or its circuit fails, the P0198 code may be triggered.

5. Severity of the P0198 code

The P0198 code usually indicates a moderate to severe fault. Although the vehicle may still be able to drive, long-term abnormal oil temperature may cause damage to the engine, such as excessive wear, overheating or poor lubrication. Therefore, it is recommended to repair it as soon as possible.

6. Can I still drive after the P0198 code appears?

Although the vehicle may still be able to drive after the P0198 code appears, it is not recommended to drive for a long time or at high speed. Because incorrect oil temperature may cause engine performance to decline, fuel consumption to increase, and even damage key components. It is recommended to send the vehicle to a repair shop for inspection and repair as soon as possible.

7. How do I fix the P0198 code myself?

For non-professionals, it may be difficult to fix the P0198 code by yourself. Because it takes professional tools and techniques to diagnose and solve the oil temperature sensor fault. It is recommended to use car diagnostic tool for detailed fault detection and location, and seek the help of professional technicians.

8. How to diagnose the P0198 code?

Diagnosing the P0198 code usually requires the use of a professional OBD2 scanner or car diagnostic tool. The technician will connect the scanner to the vehicle's OBD2 interface, read the fault code, and view the real-time data of the oil temperature sensor. In addition, voltage tests, resistance tests, and circuit continuity checks may be required to determine the specific cause of the fault.

9. How much does it cost to repair the P0198 code in the United States?

The cost of repairing the P0198 code varies depending on the model, cause of the fault, and region. Generally speaking, the cost of replacing the oil temperature sensor can range from a few hundred dollars to a thousand dollars. If the fault involves a more complex circuit problem or ECU failure, it may require a higher repair fee. It is recommended to consult a local repair shop or dealer for an accurate quote.

10. How to clear the P0198 code?

After resolving the fault and replacing or repairing any damaged parts, the P0198 code should be cleared using a professional OBD2 scanner or car diagnostic tool. It is important not to simply clear the fault code by disconnecting the negative terminal of the battery, as this may cause the vehicle control module to lose stored data, affecting performance and possibly causing other faults.

11. How to prevent the occurrence of the P0198 error code?

Preventing the occurrence of the P0198 error code requires regular vehicle care and maintenance. This includes checking the cleanliness and accuracy of the oil sensor, maintaining the integrity and sealing of the circuit, and regularly replacing aged sensors and components. In addition, using high-quality oil and additives can also help reduce contamination and wear of the oil system.

12. Other considerations about the P0198 code

• Timely repair: Once the P0198 code is found, it should be repaired as soon as possible to avoid potential engine damage and performance degradation.
• Professional repair: For complex problems such as oil temperature sensor failure, it is recommended to seek the help of a professional technician to ensure accurate diagnosis and efficient repair.
• Follow the guidance: When clearing fault codes, it is important to follow the vehicle manufacturer's specific guidelines to avoid unexpected consequences.
• Record repair history: Keeping detailed repair records can help track the source of the problem and provide reference when problems arise in the future.

13. How to Choose a Diagnostic Tool?

When purchasing an OBD2 diagnostic tool, you should consider the following factors:

• Brand and quality: Choose a well-known brand and reliable quality products to ensure accuracy and reliability.
• Functional requirements: Choose an OBD2 scan tool with appropriate functions according to the vehicle model and repair needs. For example, some advanced tools may support more car models and more detailed diagnostic information.
• Budget: Choose a suitable OBD2 scan tool according to your budget. Prices vary depending on brand, function, and quality.
• User reviews: Check other users' reviews and feedback to understand the performance and ease of use of the product.

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In short, the P0198 code is a fault code that needs to be taken seriously. By understanding its meaning, possible causes, symptoms, and diagnosis and solutions, we can better maintain the performance and reliability of our vehicles. When encountering such problems, it is recommended to contact a professional repair technician as soon as possible for detailed inspection and repair.