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Engine-Codes – Nissan – P0128 2002 Nissan Altima Sedan

P0128 2002 Nissan Altima Sedan Code - Thermostat Function

Quick Answer

The P0128 code on a 2002 Nissan Altima Sedan indicates that the engine coolant temperature is below the thermostat regulating temperature. Common causes include Faulty thermostat, Low coolant level, Coolant temperature sensor malfunction. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means
P0128 2002 Nissan Altima Sedan indicates Thermostat Function.
Common causes
Common causes include Faulty thermostat, Low coolant level, Coolant temperature sensor malfunction.
Severity
High - diagnose this code as soon as possible.
Can I drive?
Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
What is this?
Table of contents Created and updated by William Orellana on Sep 10, 2024
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Code P0128 2002 Nissan Altima Sedan Description

The P0128 code on a 2002 Nissan Altima Sedan indicates that the engine coolant temperature is below the thermostat regulating temperature. The thermostat is a crucial component of the vehicle's cooling system, responsible for regulating the engine temperature by controlling the flow of coolant. When the engine is cold, the thermostat remains closed to allow the engine to warm up quickly. Once the engine reaches the optimal operating temperature, the thermostat opens to allow the coolant to circulate and maintain a stable temperature.

OBDII Code P0128 2002 Nissan Altima Sedan - Thermostat Function
P0128 2002 Nissan Altima Sedan Code - Thermostat Function

Common Causes of P0128 2002 Nissan Altima Sedan

  1. Faulty thermostat
  2. Low coolant level
  3. Coolant temperature sensor malfunction
  4. Leaking or blocked radiator
  5. Air in the cooling system

Symptoms of P0128 2002 Nissan Altima Sedan

  1. Check engine light is illuminated
  2. Engine running colder than normal
  3. Poor fuel efficiency
  4. Heater not blowing hot air
  5. Engine overheating

How to Fix P0128 2002 Nissan Altima Sedan

  1. Begin by checking the coolant level in the radiator and reservoir to ensure it is at the proper level.
  2. Inspect the thermostat for any signs of damage or corrosion. Replace the thermostat if necessary.
  3. Check the coolant temperature sensor for proper operation and replace if faulty.
  4. Inspect the radiator for leaks or blockages, addressing any issues found.
  5. Bleed the cooling system to remove any air pockets and ensure proper circulation.

Cost to Fix P0128 2002 Nissan Altima Sedan

The cost of repairing a P0128 code on a 2002 Nissan Altima Sedan can vary depending on the specific cause of the issue. In general, the cost of replacing a thermostat ranges from $150 to $300, including parts and labor. However, additional costs may be incurred if other components need to be replaced or if there are underlying issues with the cooling system. It's recommended to consult with a professional mechanic for a more accurate estimate based on the specific circumstances of the vehicle. Keep in mind that labor rates and diagnostic fees can also impact the overall cost of repairs.

What does this mean?

Tech Notes for P0128 2002 Nissan Altima Sedan

If cooling system is not leaking and the fluid level is OK, replacing the thermostat usually takes care of the problem.

When is the Code Detected?

The engine coolant temperature does not reach to specified temperature even though the engine has run long enough.

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About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P0128 2002 Nissan Altima Sedan Code

1. What does OBDII code P0128 on a 2002 Nissan Altima Sedan indicate?

The OBDII code P0128 on a 2002 Nissan Altima Sedan indicates an issue with the thermostat function.

2. What are the common symptoms of a P0128 code on a 2002 Nissan Altima?

Common symptoms of a P0128 code on a 2002 Nissan Altima include engine overheating, a decrease in fuel efficiency, and the temperature gauge reading lower or higher than normal.

3. What are the possible causes of a P0128 code on a 2002 Nissan Altima Sedan?

Possible causes of a P0128 code on a 2002 Nissan Altima include a faulty thermostat, low coolant level, a malfunctioning coolant temperature sensor, or a stuck open thermostat.

4. How can I diagnose the cause of a P0128 code on my 2002 Nissan Altima Sedan?

To diagnose the cause of a P0128 code, you can start by checking the coolant level, inspecting the thermostat for proper operation, testing the coolant temperature sensor, and ensuring there are no leaks in the cooling system.

5. Can I continue driving my 2002 Nissan Altima with a P0128 code?

It is not recommended to continue driving your 2002 Nissan Altima with a P0128 code as it can lead to potential engine damage due to overheating.

6. How can I repair a P0128 code on my 2002 Nissan Altima Sedan?

To repair a P0128 code on a 2002 Nissan Altima, you may need to replace the thermostat, refill the coolant, reset the trouble code with an OBDII scanner, and monitor the temperature gauge for normal operation.

7. Are there any preventive maintenance tips to avoid a P0128 code on my 2002 Nissan Altima Sedan?

To prevent a P0128 code on your 2002 Nissan Altima, it is recommended to regularly check the coolant level, replace the thermostat at the manufacturer's recommended intervals, and have the cooling system inspected during routine maintenance.

8. Can a DIY enthusiast fix a P0128 code on a 2002 Nissan Altima Sedan?

A DIY enthusiast with mechanical skills and the necessary tools can potentially fix a P0128 code on a 2002 Nissan Altima by following repair guides or consulting with automotive forums for assistance.

9. Is it important to address a P0128 code promptly on a 2002 Nissan Altima Sedan?

Yes, it is important to address a P0128 code promptly on a 2002 Nissan Altima to prevent potential engine damage and ensure the vehicle operates safely and efficiently.

10. How much does it typically cost to repair a P0128 code on a 2002 Nissan Altima Sedan?

The cost to repair a P0128 code on a 2002 Nissan Altima can vary depending on the exact cause of the issue, but it may range from $100 to $300 for parts and labor.

Discuss the causes and fixes for P0128 2002 Nissan Altima Sedan OBDII Code

Submit a New Comment

  • My radiator was leaking! I fix that. The code came back on (p0128). Then I fix the thermostat. The code came on again! My heater is blowing hot air. What next? Do I need to change any sensors?

    Reply to Comment

  • Try bleeding the cooling system one more time, just to make sure there is no air in the system. If you are sure there is no air in the system, then you have to replace the Coolant Temperature Sensor.

    Reply to Comment