AutoCodes – Infiniti – P0128 2003 Infiniti G35

P0128 2003 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 2003 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.

Save to My Repairs Step-by-Step Diagnostic Guide My Repairs

AI answers can be wrong. Verify repairs with testing. Open full chat

Code Popularity 7,138

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
Add Comment

💬 Need more help? Ask Coddy for instant answers — it's free!

Code P0128 2003 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 2003 Infiniti G35 - Thermostat Function - AutoCodes.com — P0128 2003 Infiniti G35 Code - Thermostat Function

What does this mean?

What are the Possible Causes of the DTC P0128 2003 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 2003 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 2003 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 2003 Infiniti G35 code?

Need more information on how to fix the P0128 2003 Infiniti G35 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P0128 2003 Infiniti G35 code diagnosed by a professional: Find a repair shop in your area

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 2003 Infiniti G35 Code

1. What does OBDII code P0128 indicate in a 2003 Infiniti G35?

- OBDII code P0128 in a 2003 Infiniti G35 typically indicates an issue with the thermostat.

2. What are the common symptoms of a P0128 code in a 2003 Infiniti G35?

- Common symptoms of a P0128 code include the engine running colder than normal, the temperature gauge not reaching operating temperature, and a decrease in fuel efficiency.

3. What are the potential causes of a P0128 code in a 2003 Infiniti G35?

- The potential causes of a P0128 code can include a malfunctioning thermostat, a faulty coolant temperature sensor, low coolant levels, or a problem with the cooling system.

4. How can I diagnose a P0128 code in my 2003 Infiniti G35?

- To diagnose 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 2003 Infiniti G35 with a P0128 code?

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

6. How can I repair a P0128 code in my 2003 Infiniti G35?

- The most common repair for a P0128 code involves replacing the thermostat with a new one. It is also advisable to check and replace the coolant temperature sensor if needed.

7. Are there any DIY tips for fixing a P0128 code in a 2003 Infiniti G35?

- While replacing the thermostat can be a straightforward DIY task for some, it is recommended to follow the manufacturer's instructions or seek professional help to ensure proper installation and avoid complications.

8. Will resetting the OBDII system clear a P0128 code in a 2003 Infiniti G35?

- Resetting the OBDII system may temporarily clear the code, but if the underlying issue causing the P0128 code is not addressed, it is likely to reappear. It is crucial to diagnose and fix the root cause of the problem.

9. How much does it cost to repair a P0128 code in a 2003 Infiniti G35?

- The cost of repairing a P0128 code in a 2003 Infiniti G35 can vary depending on the specific cause of the issue, the parts needed, and whether you choose to do the repairs yourself or take your vehicle to a mechanic.

10. Can a P0128 code affect the overall performance of a 2003 Infiniti G35?

- Yes, a P0128 code can impact the overall performance of your vehicle by causing inefficient fuel combustion, reduced engine efficiency, and potentially triggering the check engine light.