The temperature of the coolant in an internal combustion engine is measured by a coolant temperature sensor (CTS). The sensor typically sits inside the engine block or cylinder head, and it communicates the coolant temperature to the powertrain control module (PCM) or engine control module (ECM) via a signal.
The ECM or PCM uses this data to modify the fuel injection and ignition timing, turn on the radiator fan, and control other cooling system elements. Poor engine performance, higher fuel consumption, and other problems can be brought on by a broken CTS.
This article discusses how to trick a Coolant Temp sensor, with all the relevant information you need to know. So stick around until the end to find out what you’ve been looking for. And don’t forget to leave a comment if you have any questions to ask.
Table of Contents
What does a coolant temperature sensor do, and why it is important?
As mentioned, an internal combustion engine’s coolant temperature is measured by a coolant temperature sensor (CTS), which then transmits a signal to the powertrain control module or engine control module (PCM).
The fuel injection and ignition timing, as well as the radiator fan and other cooling system components, are modified by the ECM or PCM using this data. This assists in making sure the engine is running at its ideal temperature, which can enhance performance and fuel efficiency while also guarding against engine damage brought on by overheating.
Why is CTS important in a vehicle?
It’s crucial because the engine performance is directly impacted by the coolant’s temperature. The coolant is less efficient at removing heat from the engine when it is cold, which can cause the engine to run poorly or stall.
The coolant may become less efficient at removing heat when the engine is hot, which could lead to overheating and damage.
In order to ensure that the engine operates at peak efficiency and avoids overheating, the CTS assists the engine control module in determining the ideal temperature. The engine control module will then adjust the fuel injection, ignition timing, and other parameters accordingly.
CTS also contributes to the vehicle’s emissions-control system. When the engine is in its warm-up phase, the engine’s computer uses the CTS signal to determine when to adjust the air/fuel mixture. This enhances fuel efficiency and lowers emissions.
In conclusion, CTS is critical for engine performance, fuel economy, and emission control. It also aids in preventing overheating-related engine damage.
What causes a coolant temperature sensor to go bad?
There are several factors that can cause a coolant temperature sensor (CTS) to go bad, including:
Age and wear:
Due to exposure to heat and vibration over time, the CTS may eventually become worn out or damaged. This may result in the sensor losing accuracy or malfunctioning completely.
The CTS may pick up dirt, debris, or other substances, which may obstruct its ability to precisely gauge the coolant temperature.
The CTS is a part of the electrical system, and just like other parts of the electrical system, it is susceptible to damage from corrosion, short-circuits, and overvoltage.
If the engine overheats frequently, it can cause the CTS to malfunction or fail.
If the CTS is not installed properly, it can cause the sensor to malfunction or fail.
It’s crucial to remember that a failing CTS can also result from other engine or cooling system problems, like a damaged thermostat or low coolant levels. To avoid making the mistake of assuming the problem is the CTS, it is advised to have a professional diagnose the problem.
How to tell if your coolant temp sensor is bad (bad CTS symptoms)
There are a few signs that your coolant temperature sensor (CTS) may be bad and need to be replaced. Some of the most common symptoms include:
Engine runs poorly or stalling:
The engine control module (ECM) or powertrain control module (PCM) may not be receiving accurate information about the coolant temperature if the CTS is not functioning properly. The engine may run poorly or stall as a result of this.
Check Engine Light:
A malfunctioning CTS can trigger the check engine light to come on.
Poor fuel economy:
The engine control module (ECM) or powertrain control module (PCM) may not be able to correctly adjust the fuel injection and ignition timing if the CTS is not functioning properly. This may result in poor fuel efficiency.
The engine control module (ECM) or powertrain control module (PCM) may be unable to correctly activate the radiator fan and other cooling system components if the CTS is not functioning properly. The result could be overheating.
A malfunctioning CTS can cause the engine to run richer or leaner, which can affect the vehicle’s emissions.
It’s important to remember that these symptoms can also be brought on by other problems, so it is advised to have the problem professionally diagnosed. A mechanic can test the sensor’s functionality and check the CTS signal using a scan tool. To prevent any further problems, the CTS should be replaced if it is discovered to be defective.
How to test the coolant temp sensor?
There are a few ways to test a coolant temperature sensor (CTS) to determine if it is functioning properly.
Here are a few methods:
In this test, the CTS resistance will be measured using a multimeter. The multimeter must be set to the “Ohms” setting and the sensor must be taken out of the engine to conduct this test. The multimeter’s reading ought to fall within the parameters set by the car’s creator.
In this test, the CTS signal’s voltage will be measured using a multimeter. The multimeter must be set to the “Volts DC” setting and the sensor must be connected to the engine in order to conduct this test. The multimeter should display a voltage reading while the engine is running that falls within the parameters set by the car’s maker.
Scan Tool Test:
In this test, the CTS signal will be read using a scan tool. The sensor can still be attached to the engine and tested while it is running. The coolant temperature reading from the scan tool should be visible, and it should fall within the manufacturer’s recommended range.
It’s crucial to remember that these tests are only intended to serve as general guidelines; the precise procedure will depend on the make and model of the vehicle. For the precise process for your vehicle, it is advised to consult a repair manual or a qualified mechanic.
It’s also crucial to keep in mind that a failed CTS may not always point to a defective sensor; it could also be caused by other problems like a broken thermostat or low coolant; as a result, it’s advised to have a professional diagnose the problem.
How to trick the coolant temp sensor?
It is not advised to “trick” a coolant temperature sensor (CTS), as doing so could seriously harm the engine of your car and void the warranty. The CTS is crucial to the engine’s performance, fuel economy, and emission control.
It also aids in preventing overheating-related engine damage. The engine may run poorly, stall, overheat, emit more pollutants, or have lower fuel efficiency if the sensor is bypassed or interfered with.
In some jurisdictions, tampering with the CTS or any other part of the vehicle is also prohibited and may result in fines or other consequences.
But if you still want to trick the coolant temp sensor here is how to do it.
There are several ways you can deceive your coolant temperature sensor. Installing a resistor in the wiring harness is one approach. The sensor will read a lower temperature as a result than what is actually there.
There is also the option of inserting a filter directly between the sensor and the ECU. As a result, the ECU will receive inaccurate information about the coolant temperature and will adjust as a result. It’s easy to boost your race car’s performance by tricking the coolant temperature sensor.
How much time and cost it takes to replace the Coolant temperature sensor?
The vehicle’s make, model, and the sensor’s precise location will all affect how long and how much it will cost to replace a coolant temperature sensor.
A mechanic should be able to replace the sensor in most cases in an hour or less, and the sensor itself can cost between $20 and $50. However, the cost of labor will vary based on the mechanic and the location. To get a precise estimate for a specific vehicle, it is best to get a quote from a nearby mechanic.
Some related FAQs.
What is normal coolant temp at idle?
The majority of experts concur that your engine should operate between 195 and 220 degrees. The needle should always maintain a position directly in the middle of your gauge.
Can a temp sensor affect engine starting?
You may have a bad engine coolant temperature sensor if you have starting issues but the “check engine” light doesn’t come on (ECT). They are quick and simple to swap out.