AutoCodes – Acura – P0128 Acura

P0128 Acura Code - Cooling System Malfunction

Quick Answer

The thermostat is closed when the engine coolant temperature is low, and it stops the circulation of engine coolant to speed up engine warm-up. Common causes include Low engine coolant level, Leaking or stuck open thermostat, Faulty Engine Coolant Temperature (ECT) Sensor 1. 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 Acura indicates Cooling System Malfunction.
Common causes: Common causes include Low engine coolant level, Leaking or stuck open thermostat, Faulty Engine Coolant Temperature (ECT) Sensor 1.
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 31,897

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 Aug 03, 2023

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 Acura Description

The thermostat is closed when the engine coolant temperature is low, and it stops the circulation of engine coolant to speed up engine warm-up. When the engine coolant temperature increases, the thermostat opens and circulates the engine coolant to control its temperature. When the engine coolant temperature decreases, the opening area of the thermostat is reduced to regulate the engine coolant temperature. If the thermostat sticks open, engine warm-up is delayed, and exhaust emissions are adversely affected. The Powertrain Control Module (PCM) measures the rise in the coolant temperature after the engine starts at the engine block and at the radiator, and it estimates the characteristics of the engine coolant temperature by calculations based on those two temperatures and the driving conditions. When the Engine Coolant Temperature (ECT) Sensor 2 immediately increases from the starting value, it is defined as the thermostat stuck open. When ECT Sensor 1 does not reach a specified value at a certain condition, it is defined as a thermostat malfunction.

OBDII Code P0128 Acura - Cooling System Malfunction - AutoCodes.com — P0128 Acura Code - Cooling System Malfunction

What does this mean?

What are the Possible Causes of the DTC P0128 Acura?

Low engine coolant level
Leaking or stuck open thermostat
Faulty Engine Coolant Temperature (ECT) Sensor 1
Faulty Engine Coolant Temperature Sensor 2
Faulty Intake Air Temperature (IAT) Sensor
Faulty Manifold Absolute Pressure (MAP) Sensor
Faulty Crankshaft Position (CKP) Sensor
Faulty Barometric Pressure (BARO) Sensor
Faulty Radiator Fan

How to Fix the DTC P0128 Acura?

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

When troubleshooting a 2000-2001 Accord or 2001-2002 Civic, if the PGM Tester tells you there is a DTC P0128 (Cooling System Malfunction) or P1486 (Cooling System Malfunction) set, it's really reporting the same thing. DTC P0128 is an SAE or generic Diagnostic Trouble Code (DTC) while P1486 is a manufacturer-specific DTC. Since these DTCs are similar, the PGM Tester sometimes reports a P0128 when it detects a P1486 or vice versa.

User Submitted Video

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0128 Acura 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 Acura code?

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

Need Help with the Code?

Get the P0128 Acura 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 Acura Code

1. What are the common symptoms of an OBDII code P0128 in an Acura?

The common symptoms include the engine running hotter or colder than normal, a decrease in fuel economy, and the temperature gauge showing unusual readings.

2. What are the possible causes of a P0128 code in an Acura?

Possible causes include a faulty thermostat, a malfunctioning coolant temperature sensor, low coolant levels, a leaking or stuck open thermostat, or issues with the cooling fan.

3. How can I diagnose a P0128 code in my Acura?

You can diagnose a P0128 code by checking the coolant level, inspecting the thermostat for proper operation, testing the coolant temperature sensor, and ensuring that the cooling fan is functioning correctly.

4. Can I still drive my Acura with a P0128 code?

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

5. How do I repair a P0128 code in my Acura?

To repair a P0128 code, you may need to replace the thermostat, coolant temperature sensor, or address any cooling system issues. It is recommended to have a professional mechanic diagnose and repair the problem.

6. Will resetting the check engine light resolve a P0128 code in my Acura?

Resetting the check engine light may temporarily remove the warning, but if the underlying issue causing the P0128 code is not addressed, the light will likely come back on. It is essential to diagnose and repair the problem.

7. Can a P0128 code be triggered by a faulty coolant temperature sensor?

Yes, a faulty coolant temperature sensor is a common cause of a P0128 code. If the sensor is not reading the coolant temperature correctly, it can lead to improper engine cooling operation.

8. What are the potential risks of ignoring a P0128 code in my Acura?

Ignoring a P0128 code can lead to engine overheating, which can cause severe damage to the engine components and result in costly repairs. It is crucial to address cooling system issues promptly.

9. How long does it typically take to repair a P0128 code in an Acura?

The repair time for a P0128 code can vary depending on the exact cause of the issue. Simple fixes like replacing a thermostat may take a couple of hours, while more complex problems could take longer.

10. Is it possible to prevent a P0128 code from occurring in my Acura?

Regular maintenance of the cooling system, including checking coolant levels, inspecting the thermostat, and addressing any leaks promptly, can help prevent a P0128 code from occurring in your Acura.

Discuss the causes and fixes for P0128 Acura OBDII Code

Submit a New Comment

LeAnder Bean
Date: February 24, 2018 at 6:51 pm

My 2002 acura tl s type almost redlines between switching gears and jerks the car hard i dont know what it is can someone help me.

Reply to Comment
OBDIITech
Date: February 26, 2018 at 4:17 pm

The symptoms you have described sounds like you may have a problem with the transmission and it's not related to the P0128 code. You should start by checking the transmission fluid level and condition. Do you have any more codes besides the P0128 code?

Reply to Comment