AutoCodes – Honda – P0128 2021 Honda CR-V

P0128 2021 Honda CR-V 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 2021 Honda CR-V 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.

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Code Popularity 311

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
Cost to Diagnose
FAQs
Comments
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Code P0128 2021 Honda CR-V 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 2021 Honda CR-V - Cooling System Malfunction - AutoCodes.com — P0128 2021 Honda CR-V Code - Cooling System Malfunction

What does this mean?

What are the Possible Causes of the DTC P0128 2021 Honda CR-V?

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 2021 Honda CR-V?

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 is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0128 2021 Honda CR-V 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 2021 Honda CR-V code?

Need more information on how to fix the P0128 2021 Honda CR-V code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P0128 2021 Honda CR-V 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 2021 Honda CR-V Code

1. What are the common symptoms of OBDII code P0128 in a 2021 Honda CR-V?

The common symptoms of OBDII code P0128 in a 2021 Honda CR-V include the engine running hotter than normal, a decrease in fuel economy, and the Check Engine light illuminating on the dashboard.

2. What are the possible causes of a Cooling System Malfunction in a 2021 Honda CR-V triggering code P0128?

Possible causes of a Cooling System Malfunction in a 2021 Honda CR-V triggering code P0128 include a faulty thermostat, low coolant levels, a malfunctioning coolant temperature sensor, or issues with the radiator or water pump.

3. How serious is OBDII code P0128 in a 2021 Honda CR-V?

OBDII code P0128 in a 2021 Honda CR-V indicates a potential issue with the cooling system, which is crucial for the engine's proper functioning. It is essential to address this code promptly to prevent overheating and potential engine damage.

4. Can I continue driving my 2021 Honda CR-V with OBDII code P0128?

It is not recommended to continue driving your 2021 Honda CR-V with OBDII code P0128, as it signifies a cooling system malfunction. Driving with this issue can lead to overheating, engine damage, and potential safety hazards.

5. How can I diagnose and repair OBDII code P0128 in my 2021 Honda CR-V?

To diagnose and repair OBDII code P0128 in your 2021 Honda CR-V, start by checking the coolant level, inspecting the thermostat, testing the coolant temperature sensor, and examining the radiator and water pump for any issues. Depending on the findings, you may need to replace faulty components or perform a cooling system flush.

6. Can a DIY enthusiast fix OBDII code P0128 in a 2021 Honda CR-V?

While some DIY enthusiasts may have the skills to address OBDII code P0128 in a 2021 Honda CR-V, it is often recommended to seek professional assistance, especially when dealing with the cooling system. Improper repairs can lead to further complications and costly damage.

7. How much does it cost to repair OBDII code P0128 in a 2021 Honda CR-V?

The cost to repair OBDII code P0128 in a 2021 Honda CR-V can vary depending on the underlying issue causing the cooling system malfunction. Expenses may include parts, labor, and diagnostic fees, with the total cost ranging from a few hundred to over a thousand dollars.

8. Will resetting the Check Engine light resolve OBDII code P0128 in a 2021 Honda CR-V?

Resetting the Check Engine light may temporarily turn off the warning indicator, but it will not address the root cause of OBDII code P0128 in a 2021 Honda CR-V. It is crucial to diagnose and repair the cooling system issue to prevent further complications.

9. How often does OBDII code P0128 occur in 2021 Honda CR-V vehicles?

OBDII code P0128, indicating a cooling system malfunction, can occur in 2021 Honda CR-V vehicles due to various factors such as wear and tear, component failures, or maintenance issues. Regular maintenance and prompt attention to cooling system problems can help minimize the occurrence of this code.

10. Can extreme weather conditions contribute to triggering OBDII code P0128 in a 2021 Honda CR-V?

Extreme weather conditions, such as very high or low temperatures, can potentially contribute to triggering OBDII code P0128 in a 2021 Honda CR-V. It is essential to ensure that the cooling system is properly maintained and functioning optimally to prevent issues in varying weather conditions.