Does your OBD 2 scanner display the P0128 error code? Most makes and models of vehicles can be affected by this generic trouble code. During engine operation, your powertrain control module detects an abnormal temperature reading and signals the code.
This occurs when your thermostat doesn’t read a temperature correctly or doesn’t read any temperature at all. Intake air temperature sensor readings, vehicle running time, and engine coolant temperature sensor readings are used to reach this conclusion.
What Does Honda P0128 Mean?
The Honda P0128 code indicates that the coolant thermostat temperature is below the regulating temperature. When a vehicle’s engine reaches and maintains the correct temperature, the engine control module (ECM) records the time it takes.
In order to maintain the efficient air-to-fuel ratio of 14.7:1, the powertrain control module enters a “closed-loop” with the fuel system when the engine operating temperature reaches the correct level.
Within 15 minutes of starting the engine, most ECMs require the engine coolant temperature sensor to record temperatures over 160°F. During operation, the recorded engine temperature must not fall below 160°F once the 160°F threshold has been reached.
Both of these criteria must be met in order for the PCM to record. The Honda P0128 code is triggered if either fault is recorded again on the next engine start.
Why Does The P0128 Code Appear?
Most often, the error code is caused by a leaking cooling system or a malfunctioning thermostat. Until the engine reaches the appropriate temperature, the thermostat prevents coolant from entering the radiator.
By doing this, you’ll be able to ensure that the engine reaches the optimal temperature within the set timeframe.
When a thermostat malfunction, the optimal temperature cannot be reached within the time, resulting in an error code. Other possible causes of the error code include:
- Warm-Up Time Insufficient
- Engine Coolant Temperature (ECT) sensor malfunction
- Low engine coolant level
- The thermostat is stuck open
P0128 Code Symptoms: What Are They?
There are other symptoms that can indicate there’s something wrong with the coolant thermostat besides the check engine light turning on:
- Temperature fluctuations in the engine
- It takes too long for the vehicle to warm up
- Fuel efficiency has been reduced
- Low readings on the temperature gauge
- An idle that is higher than normal
What Can You Do To Fix The P0128 Error?
You can start by repairing low coolant levels, which is the easiest fix. To start your engine, turn it off and let it cool sufficiently before opening the coolant reservoir. Coolant systems are pressurized under normal operation.
You can compare the levels and strength of your coolant with those recommended in your service manual once your engine and coolant system are cool enough to inspect safely.
Despite the likely cause of this trouble code being the thermostat, inspecting it can be a challenge. There may be no visible signs of damage to a faulty thermostat.
A stuck engine coolant thermostat is the most common cause of P0128. It is simple to check this by feeling the radiator hose and watching how hot the coolant becomes when it flows through the hose.
If you open a hot coolant system without being careful, you could suffer burns and other injuries. If you are having problems, you should always seek expert assistance. You may be asked to replace or repair the following:
It is possible that they will ask you to replace the thermostat. It may be necessary to replace the coolant temperature sensor or the wiring and other components of the damaged sensor.
It is recommended that the hose is barely warm when the thermostat opens. The radiator hose should rapidly warm up when the thermostat opens and hot coolant flows. Radiator hoses that heat slowly indicate a stuck thermostat or a prematurely opening thermostat.
How Much Does It Cost To Diagnose Honda Code P0128?
Most shops begin diagnosing your car with an hour of “diag time” (labor time spent in labor diagnosing the problem). The cost of diagnosing Honda’s P0128 code is one hour of labor.
A vehicle’s make, model, and even the type of engine can affect the diagnosis time and labor rate for auto repair. The average auto repair shop charges between $75 and $150 per hour.
The cost of this typically ranges between $75 and $150, depending on the shop’s labor rate. In most cases, if you ask a shop to perform your repairs, they will apply this diagnosis fee to your repairs. It will be possible for a shop to give you an accurate estimate for Honda P0128 code repairs from there.
The Cost Of Repairing P0128
In order to fix the underlying issue associated with the Honda P0128 code, one or more of the following repairs may be necessary. Depending on the type of repair, the estimated cost of repair includes both the cost of the necessary parts and the cost of labor.
- The purge control valve is faulty
- Valve for venting is faulty
- Canister for charcoal
- The fuel tank
- Evaporative emissions hoses
- Gas cap that is loose or damaged
P0128: How Serious Is It?
There is no need for you to take immediate action in response to this error code. The only problem is that if you don’t get it right away, your engine may be damaged. Here’s how it works.
It will not be possible to burn the condensation if the coolant doesn’t get hot enough, resulting in water getting on the oil. Your car’s engine can be damaged by this process over time.
Is It Possible To Drive With This Problem For A Long Time?
Due to the fact that this is not a serious issue, you should be able to drive your car for as long as you like. You won’t have to worry about your car suddenly stopping. This issue won’t interfere with your driving. It can, however, cause expensive damage in the long run.
Can I Drive With The P0128 Code?
In spite of the code, the check engine light will still stay illuminated, so you can still drive your car. Neither will it hinder the vehicle’s operation nor cause the vehicle to shut down suddenly.
It’s only the temperature gauge that isn’t reaching optimal levels that will be the problem. Your car’s engine and performance may be damaged over time as a result of this. The best thing to do is to have it checked by a professional.
The running temperature of your engine is often the cause of trouble code P0128, but faulty thermostats are by far the most common cause. Different vehicles have different thermostat locations and different issues associated with damaged thermostats.
It is also related to this issue for most vehicles with trouble code P0125. Make sure this code is fixed within the next month to avoid overheating. Whenever a code appears on your vehicle, take it to a reputable mechanic for diagnosis.
As a result, you might end up with more repairs and higher expenses in the long run if you let the damage progress to other parts of the vehicle. Detect code p0128 symptoms early on, and fix what needs to be fixed to avoid this problem.