AutoCodes – Honda – P0128 2020 Honda CR-V

P0128 2020 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 2020 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 342

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 2020 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 2020 Honda CR-V - Cooling System Malfunction - AutoCodes.com — P0128 2020 Honda CR-V Code - Cooling System Malfunction

What does this mean?

What are the Possible Causes of the DTC P0128 2020 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 2020 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 2020 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 2020 Honda CR-V code?

Need more information on how to fix the P0128 2020 Honda CR-V code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P0128 2020 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 2020 Honda CR-V Code

1. What does OBDII code P0128 indicate in a 2020 Honda CR-V?

- OBDII code P0128 in a 2020 Honda CR-V typically indicates a cooling system malfunction.

2. What are the common symptoms of OBDII code P0128 in a 2020 Honda CR-V?

- Common symptoms include the engine running hotter or colder than normal, a temperature gauge reading lower than usual, and a potential decrease in fuel efficiency.

3. What are the possible causes of OBDII code P0128 in a 2020 Honda CR-V?

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

4. How can I diagnose the cooling system issue causing OBDII code P0128 in my 2020 Honda CR-V?

- 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 fan is functioning correctly.

5. Can I continue driving my 2020 Honda CR-V with OBDII code P0128?

- It is not recommended to continue driving your vehicle with OBDII code P0128, as it can lead to potential engine damage from overheating or cooling system failure.

6. How can I repair OBDII code P0128 in my 2020 Honda CR-V?

- The repair process may involve replacing the thermostat, topping up coolant levels, replacing the coolant temperature sensor, or addressing any cooling fan issues identified during diagnosis.

7. Are there any DIY tips for troubleshooting OBDII code P0128 in a 2020 Honda CR-V?

- DIY tips include checking coolant levels regularly, ensuring the radiator and cooling system are free of leaks, testing the thermostat for proper function, and monitoring the temperature gauge for any abnormalities.

8. Is it necessary to reset the OBDII code P0128 after fixing the cooling system issue in my 2020 Honda CR-V?

- Yes, it is recommended to reset the OBDII code P0128 after fixing the cooling system issue to clear the fault code from the system and ensure proper monitoring of the system moving forward.

9. Can extreme weather conditions contribute to triggering OBDII code P0128 in a 2020 Honda CR-V?

- Yes, extreme weather conditions such as very cold temperatures can impact the proper functioning of the cooling system and potentially trigger OBDII code P0128 in your Honda CR-V.

10. How often should I have the cooling system checked in my 2020 Honda CR-V to prevent OBDII code P0128 from occurring?

- It is recommended to have the cooling system checked during regular maintenance intervals, typically every 30,000 to 50,000 miles, to prevent issues that could trigger OBDII code P0128.