AutoCodes – Infiniti – P0128 2005 Infiniti G35

P0128 2005 Infiniti G35 Code - Thermostat Function

Quick Answer

The thermostat is a component that blocks the flow of coolant to the radiator until the engine has warmed up. Common causes include Leaking or stuck open thermostat, Low engine coolant level, Insufficient warm up time. 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 2005 Infiniti G35 indicates Thermostat Function.
Common causes: Common causes include Leaking or stuck open thermostat, Low engine coolant level, Insufficient warm up time.
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.

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Code Popularity 6,249

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Intermediate (2 / 3)

What is this?

Table of contents Created and updated by William Orellana on Apr 21, 2019

Description
Step-by-Step Diagnostic Guide
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code P0128 2005 Infiniti G35 Description

The thermostat is a component that blocks the flow of coolant to the radiator until the engine has warmed up. When the engine is cold, no coolant flows through the engine. Once the engine reaches its operating temperature, the thermostat opens. The OBDII sets when the engine coolant temperature has not risen enough to open the thermostat even though the engine has run long enough. This is due to a leak in the seal or the thermostat open stuck.

OBDII Code P0128 2005 Infiniti G35 - Thermostat Function - AutoCodes.com — P0128 2005 Infiniti G35 Code - Thermostat Function

What does this mean?

What are the Possible Causes of the DTC P0128 2005 Infiniti G35?

Leaking or stuck open thermostat
Low engine coolant level
Insufficient warm up time
Faulty engine coolant temperature sensor
Engine coolant temperature sensor harness is open or shorted
Engine coolant temperature sensor circuit poor electrical connection

How to Fix the DTC P0128 2005 Infiniti G35?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What does this mean?

Code Tech Notes

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

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0128 2005 Infiniti G35 code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

Need more information about the P0128 2005 Infiniti G35 code?

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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 2005 Infiniti G35 Code

1. What does OBDII code P0128 mean for a 2005 Infiniti G35?

The P0128 code indicates that the engine coolant temperature is below the thermostat regulating temperature.

2. What are common symptoms of a P0128 code in a 2005 Infiniti G35?

Common symptoms include the engine running colder than normal, poor fuel economy, and the Check Engine light being illuminated.

3. What are the possible causes of a P0128 code in a 2005 Infiniti G35?

Potential causes include a faulty thermostat, low coolant level, a malfunctioning coolant temperature sensor, or a problem with the cooling system.

4. How can I diagnose the cause of a P0128 code in my 2005 Infiniti G35?

Diagnosis typically involves checking the coolant level, inspecting the thermostat, testing the coolant temperature sensor, and ensuring the cooling system is functioning properly.

5. Can I continue driving my 2005 Infiniti G35 with a P0128 code?

It is not recommended to drive with a P0128 code, as it can lead to overheating and potentially damage the engine. It is best to address the issue promptly.

6. How can I repair a P0128 code in my 2005 Infiniti G35?

Repairing a P0128 code often involves replacing the thermostat, addressing any coolant leaks, checking and replacing the coolant temperature sensor if necessary, and ensuring proper coolant circulation.

7. What is the function of the thermostat in a 2005 Infiniti G35's cooling system?

The thermostat regulates the flow of coolant through the engine to maintain optimal operating temperature, ensuring efficient engine performance and longevity.

8. How important is it to address a P0128 code in a 2005 Infiniti G35?

Addressing a P0128 code promptly is crucial to prevent potential engine damage due to overheating and to maintain optimal engine performance and fuel efficiency.

9. Can a DIY enthusiast repair a P0128 code in a 2005 Infiniti G35?

Depending on your skill level, replacing the thermostat and addressing common causes of the P0128 code can be done by a DIY enthusiast with the necessary tools and knowledge.

10. How often should the thermostat be replaced in a 2005 Infiniti G35?

The thermostat in a 2005 Infiniti G35 should typically be replaced as part of routine maintenance or if issues arise, such as the triggering of a P0128 code.