AutoCodes – Honda – P0128 2009 Honda Accord

P0128 2009 Honda Accord Code - Coolant System Malfunction

Quick Answer

Indicates that the thermostat monitor has not achieved the required engine operating temperature within a specified amount of time after starting the engine. 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 2009 Honda Accord indicates Coolant System Malfunction.
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 9,019

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 Jun 14, 2020

Description
Step-by-Step Diagnostic Guide
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code P0128 2009 Honda Accord Description

Indicates that the thermostat monitor has not achieved the required engine operating temperature within a specified amount of time after starting the engine.

OBDII Code P0128 2009 Honda Accord - Coolant System Malfunction - AutoCodes.com — P0128 2009 Honda Accord Code - Coolant System Malfunction

What does this mean?

What are the Possible Causes of the DTC P0128 2009 Honda Accord?

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 2009 Honda Accord?

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 2009 Honda Accord 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 2009 Honda Accord 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 2009 Honda Accord Code

1. What are common symptoms of OBDII code P0128 on a 2009 Honda Accord?

- Common symptoms include the engine running hotter or cooler than normal, a lack of heat from the heater, and the Check Engine light being illuminated.

2. What are the possible causes of OBDII code P0128 on a 2009 Honda Accord?

- Possible causes include a faulty thermostat, low coolant levels, a malfunctioning coolant temperature sensor, or a problem with the cooling system.

3. How can I diagnose the source of OBDII code P0128 on my 2009 Honda Accord?

- You can diagnose the issue by checking the coolant level, inspecting the thermostat for proper operation, testing the coolant temperature sensor, and ensuring the cooling system is functioning correctly.

4. Is it safe to continue driving my 2009 Honda Accord with OBDII code P0128?

- It is not recommended to continue driving with this code as it can lead to overheating and potential engine damage. It is best to address the issue promptly.

5. Can I reset the OBDII code P0128 on my 2009 Honda Accord by disconnecting the battery?

- While disconnecting the battery can clear the code temporarily, it is not a permanent solution. The underlying issue causing the code needs to be diagnosed and repaired.

6. How much does it typically cost to repair OBDII code P0128 on a 2009 Honda Accord?

- The cost of repairs can vary depending on the specific cause of the code. It can range from a simple thermostat replacement to more extensive cooling system repairs.

7. What are some DIY tips for addressing OBDII code P0128 on a 2009 Honda Accord?

- DIY tips include checking and topping up coolant levels, inspecting the thermostat for proper function, and visually inspecting the cooling system components for any obvious issues.

8. Can a clogged radiator cause OBDII code P0128 on a 2009 Honda Accord?

- Yes, a clogged radiator can restrict coolant flow and cause the engine to run hotter than normal, triggering the P0128 code.

9. Will replacing the coolant temperature sensor fix OBDII code P0128 on a 2009 Honda Accord?

- While a faulty coolant temperature sensor can cause the code, it is recommended to diagnose the issue thoroughly to ensure the correct component is replaced.

10. How long does it take to repair OBDII code P0128 on a 2009 Honda Accord?

- The repair time can vary depending on the specific cause of the code and the extent of the repairs needed. Simple fixes like replacing a thermostat can be done in a few hours, while more complex issues may take longer.