P0128 Mitsubishi Code - Coolant Thermostat 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 Mitsubishi indicates Coolant Thermostat 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.
Code P0128 Mitsubishi Description
What are the Possible Causes of the DTC P0128 Mitsubishi?
- 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 Mitsubishi?
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.
Code Tech Notes
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the P0128 Mitsubishi 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 Mitsubishi code?
Need more information on how to fix the P0128 Mitsubishi code? Get Access to Factory Service Manuals
Need Help with the Code?
Get the P0128 Mitsubishi code diagnosed by a professional: Find a repair shop in your area
Frequently Asked Questions about P0128 Mitsubishi Code
1. What does the OBDII code P0128 mean on a Mitsubishi?
P0128 indicates that the engine’s coolant temperature is not reaching the expected threshold in a timely manner, often due to a thermostat malfunction.
2. What are the common symptoms of code P0128?
Symptoms include an illuminated check engine light, poor fuel efficiency, lower engine temperature readings, and reduced cabin heater performance.
3. What causes code P0128 on a Mitsubishi?
Common causes include a stuck-open thermostat, low coolant levels, a faulty coolant temperature sensor, or issues with the cooling system.
4. Can I drive my Mitsubishi with a P0128 code?
While it’s possible to drive, prolonged use can lead to poor fuel economy and increased engine wear due to improper operating temperatures.
5. How do I fix a P0128 code on a Mitsubishi?
Repairs may involve replacing the thermostat, refilling coolant, checking for leaks, or replacing the coolant temperature sensor.
6. How much does it cost to fix a P0128 code?
The cost varies, but replacing a thermostat typically costs $150-$300, including parts and labor, depending on the model.
7. Will clearing the P0128 code fix the problem?
Clearing the code doesn’t resolve the underlying issue; you must identify and repair the cause to prevent the code from returning.
8. Can a P0128 code affect fuel economy?
Yes, an engine running cooler than designed can cause inefficient combustion, leading to lower fuel efficiency.
9. How can I diagnose a P0128 code on a Mitsubishi?
Diagnose by checking coolant levels, inspecting the thermostat, testing the coolant temperature sensor, and ensuring the cooling system is functioning properly.
10. What happens if I ignore a P0128 code?
Ignoring the code can lead to reduced engine performance, higher fuel consumption, and potential long-term damage due to improper engine temperatures.
Discuss the causes and fixes for P0128 Mitsubishi OBDII Code
Code P0128 Mitsubishi comments
No comments found for this page.
Fix Your Car Smarter
Try the New AutoCodes App!
Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.
