Engine-Codes.com
Engine-Codes – Infiniti – P0128 Infiniti

P0128 Infiniti Code - Thermostat Function

Quick Answer

The P0128 diagnostic trouble code (DTC) in Infiniti vehicles indicates that the engine coolant temperature is running below the thermostat regulating temperature. Common causes include Faulty thermostat, Low coolant level, Coolant leaks. 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 Infiniti indicates Thermostat Function.
Common causes
Common causes include Faulty thermostat, Low coolant level, Coolant leaks.
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 Aug 30, 2024
💬 Need more help? Ask Auto Expert for instant answers — it's free!
AutoCodes App

Fix Your Car Smarter

Try the New AutoCodes App!

Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.

AutoCodes App on Google Play

Code P0128 Infiniti Description

The P0128 diagnostic trouble code (DTC) in Infiniti vehicles indicates that the engine coolant temperature is running below the thermostat regulating temperature. The thermostat is a crucial component responsible for regulating the engine's operating temperature by controlling the flow of coolant through the engine. When the thermostat fails to function properly, it can lead to inefficient engine performance, reduced fuel efficiency, and potential long-term damage to engine components.

OBDII Code P0128 Infiniti - Thermostat Function
P0128 Infiniti Code - Thermostat Function

Common Causes of P0128 Infiniti

  1. Faulty thermostat
  2. Low coolant level
  3. Coolant leaks
  4. Stuck open thermostat
  5. Electrical issues with the coolant temperature sensor

Symptoms of P0128 Infiniti

  1. Engine running colder than normal
  2. Decreased fuel efficiency
  3. Slow engine warm-up
  4. Illumination of the check engine light
  5. Poor heater performance in the cabin

How to Fix P0128 Infiniti

  1. Perform a diagnostic scan to confirm the P0128 trouble code and check coolant levels.
  2. Inspect the thermostat for proper operation or replace it if faulty.
  3. Check for coolant leaks and repair as necessary.
  4. Test the coolant temperature sensor for accuracy and replace if needed.
  5. Refill the coolant system and bleed out any air pockets.

Cost to Fix P0128 Infiniti

The cost of repairing a P0128 code in an Infiniti can vary depending on the specific model, location, and the extent of the issue. On average, the repair costs for this issue could range from $150 to $400, including parts and labor. It is recommended to consult with a professional mechanic for a more accurate estimate based on the specific circumstances.

What does this mean?

Tech Notes for P0128 Infiniti

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.

Need more information about the P0128 Infiniti code?

Need more information on how to fix the P0128 Infiniti code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P0128 Infiniti code diagnosed by a professional: Find a repair shop in your area

Information for Specific Infiniti Models

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 Infiniti Code

No Frequently Asked Questions about P0128 Infiniti Code found.

Discuss the causes and fixes for P0128 Infiniti OBDII Code

Submit a New Comment

Code P0128 Infiniti comments

No comments found for this page.