How Does A Coolant Temperature Sensor Work


can someone tell me where thhe coolant temperature sensor is located on a 97 Seville. But how does this car temperature sensor really work—and what's its purpose? How the Temperature Sensor Works. The engine temp sensor is different on most cars than the coolant sensor even though they both measure coolant temperature (usually). Checked oil. You can troubleshoot coolant temperature sensor problems by watching the temperature gauge on your vehicle. it just has a wire dangling off of it. A bad coolant sensor can also prevent the system from going into closed loop because the computer also considers engine coolant temperature when deciding whether or not to go into closed loop. Test coolant sensor ohms or voltage? Many inexpensive shop manuals tell you to test an engine coolant temperature sensor using an ohmmeter. Some vehicles have both a coolant temperature sensor and a temperature sending unit, which works similarly to a sensor but gives the reading to the gauge on the dash instead of to a computer. Coolant sensor While manufacturers use different types of coolant-level sensors, the simplest is a float that activates a switch. Coolant Temperature Sensor (2009+ TDI) About Us IDParts. The O2 sensor works like a miniature generator and produces its own voltage when it gets hot. You can do it at home using a digital multimeter and a cooking thermometer. The G62 temperature sensor is a fairly common component to go on the Audi A4, typically this can be diagnosed via vag-com codes such as 17664. Oxygen sensors do this through a chemical reaction inside the sensor itself; in this article we will explain the evolution and application of this very important piece of the fuel injection puzzle. If you get a sensor from the dealer it will have some red sealer on the threads that makes it ready to install. How does a CTS work? The CTS is a thermistor that measures the temperature and sends a signal back to the ECU. Do Engine Coolant TTemp Sensor and Dash Temp Gauge work independently? Hello, I bought a 2004 BMW 325ci, it overheats, it had a dtc saying something about coolant temperature circuit or sensor, I cleared, and don't know the exact DTC number. hot wire coolant fan. This is only a very crude test that only checks that the sensor resistances changes with temperature. If it closes, then the circuit is completed and the dash light comes on. The sensor modifies a voltage signal from the Engine Control Module. So If it was the green Sensor what would it make the car do? And what if it was the other one that was bad what would it do? Please give me the diffents. When the engine is cold the resistance increases. So how does that happen?. It does this through changing resistance and sends this information to the onboard computer. The thermostat needs to be opening and closing at the proper temperature levels and not sticking, and the water pump needs to be working so it can circulate the coolant thru the engine, radiator and heater core. The radiator outlet temperature sensor might be the cause of a hard to find coolant leak. Don't just buy a new one, they aren't hard to check, save it for beer money. My car is a 1998 LS400 with 118,. This will then translate to how the engine runs. i have a 92 gmc 1500 with 4. Below it can be seen circled. i have a coolant temperature sensor (the one that's in the thermostat housing) that is not connected to anything. At start up it appears that all eight cylinders get two pulses of fuel, all eight cylinders at the same time. When the engine is cold, no coolant flows through the engine. Most (ECT) sensors operate using electrical resistance to measure the temperature of the coolant. The effect creates a temperature difference by transferring heat between two electrical junctions. Latemodel Restoration Supply also offers your coolant temp sensor connector, wire terminal to your Mustang sending unit. All of the previously mentioned topics can affect the operating temperature of the engine coolant. As the engine warms, it will rise steadily to 200 to 230 degrees Fahrenheit. People normally figure this out in the winter when their heater "stops working". Various Engine Sensors Types of Engine Sensors: A thermocouple sensor is a temperature measuring device. How does this wire get. First, ive noticed on ******** that there are 3 different coolant temperature sensors?. How to Save on Coolant Temperature Sensor Replacement If you know for sure that the sensor is the issue, then you can replace it without much trouble. Many forums suggest this is due to a faulty “Blue” temperature sensor. Without a properly operating cooling system, the engine will run hot which will cause the engine to operate inefficiently and may result in serious damage. It warmed up to about 215 220 and I am thinking that the temp senor is not the problem but for 22 dollars I am considering this a future job done now. My car is a 1998 LS400 with 118,. The radiator outlet temperature sensor might be the cause of a hard to find coolant leak. It will also alert you for if the temperature within the system is rising for some reason. How does an intake air temperature sensor work? Most intake air temperature sensors are either positive temperature coefficient or negative temperature coefficient thermistors. The heater core and radiator need to be kept cleaned out and leak free to be able to disperse the heat from the engine properly. Mixing the orange and green colored engine coolants will produce a brown coolant which may be a customer satisfaction issue as it looks like rust is present. The Engine Coolant Temperature sensor (ECT) is located in a coolant passage in the engine usually near the thermostat. The Coolant Temperature Sensor, also referred to as Engine Coolant Temperature Sensor, is a very important monitoring device in order for your vehicle's engine to operate efficiently. There are about two commonly used coolant sensors today. TEST 1: Checking the Temperature with the Key On Engine Off. This is the latest DS18B20 1-Wire digital temperature sensor from Maxim IC. This article shows how to replace the thermostat and coolant temperature sensor on an a4 chassis mk4 TDI. Get them at NAPA. So maybe I should get both sensors (temp sender and temp sensor)? Just not actually sure where the sensors are located. What is the abbreviation for Coolant Temperature Sensor? What does CTS stand for? CTS abbreviation stands for Coolant Temperature Sensor. The sensor is a temperature sensor with a negative temperature coefficient. The one for the ECM. Back to your temp sensor. They are typically 2 pin devices. The fault was:-. Low Coolant Alarm. Unlike Your Steering Wheel in Seconds with These Two Tricks; How to Paint Your Car Wheels Like a Pro; Step 1: Locating the Coolant Temperature Sensor. The coolant level sensor is the electronic sensor that is responsible for measuring the coolant level of your engine. What is Engine Coolant / Antifreeze This guide explains ‘What is engine coolant / antifreeze, what it does, why you should use it, what type of antifreeze / coolant to use and where to put it’. The ECM determines when. One of the things that will help you solve a ECT temperature problem is knowing how it works. Set the multimeter to the resistance setting, and connect the test leads to terminals 2 and 4. Coolant level sensor; how does it work?It's from a 1993 Pontiac Grand Am. Most modern vehicles use two engine coolant temperature sensors, one for the gauge and and one for the computer. To help determining whether a coolant temperature sensor is functioning correctly, different possible deviations from the example signal are mentioned along with probable causes. It may well come back to life next time you start the car, and this is a telltale sign that the sensor's on its last legs. Lower Your Coolant Temperature High temperatures can cause lots of problems. The modified signal returns to the ECM as the engine coolant temperature input. If in doubt about when to flush your car’s cooling system, consult your vehicle handbook or the instructions provided by the coolant/antifreeze. The computer will send another signal to the engine temperature gauge, and alert the driver if the temperature exceeds the specified range for that vehicle. This article shows how to replace the thermostat and coolant temperature sensor on an a4 chassis mk4 TDI. With a lab scope a coolant temperature sensor is measured from an engine in a warming up stage. Again - thanks for the help. The sensor keeps tabs on the operating temperature and alerts the on-car computer when there's a potential problem. The temperature that the sensor reads is then sent to the on-board computer or engine control system as a signal. Does the coolant sensor have anything to do with the heavy smoke? The turbo hoses are not broke or cracked. After the warranty ran out I discovered the real problem was foam in the coolant causing the sensor to show low coolant. The coolant sensor just operates the gauge or light on the dash and on the newer cars in some cases will also send that info to the computer in order for the computer to compare the information for a more. The coolant temp sensor is usually located on the intake manifold or the water inlet to the engine. The only thing I can think of, is that my manual is outdated and my model uses just the one sensor that sports the one wire. asadi wrote: >Asking those more knowledgeable than I, I pose the following > >The 'Auto Zone' diagnostic trouble code was for the coolant temperature >sensor. Bad Coolant Temperature Sensor Symptoms. Get them at NAPA. Dip the sensor in boiling water. Add to Compare. But what does this sensor do, and why does it matter?. I had to do some searching before I finally found it. Does your car have air conditioning? If it does, are you sure that the controls are not set for defrost and that the fan speed control is Off? It's possible that the engine coolant temperature sensor has become too sensitive, and is triggering the fans to come on a bit too early. This is accomplished by blocking the circulation of coolant between the engine and radiator until the engine has reached its predetermined temperature. Oxygen sensors work through a chemical reaction. (In general, Evans does not recommend raising the fan-on temperature more than about 25⁰F. Engine Coolant Temperature Sensors. AC Fan/Compressor Not Working - How To Test /Repair Broken HVAC Run Start Capacitor Air Condition HD - Duration: 26:33. engine coolant temperature. This sensor is usually on top of the engine somewhere, plugged into a coolant passage, not in the radiator. It is the job of the ambient temperature sensor to measure the external temperature of the vehicle as a reference point for the computer to make calculations. On most vehicles, the coolant temperature sensor (CTS) can be found somewhere near the engine thermostat, which. 3 engine's major components. The coolant temperature sensor is what tells the car's computer what the engine's running temperature is. The Ford basic part# is 6G004. mine seems to only have one wire. If the engine is warmed up, you can bypass the temp sensor with a jumper wire at the temp sensor harness. Coolant temperature gage does not work replace temp sensor in block still does not work put a paper clip in plug and - Answered by a verified Ford Mechanic We use cookies to give you the best possible experience on our website. Steve83 wrote:The one up front is the Engine Coolant Temp sensor (ECT), which is strictly for the computer. Cummins Diesel Coolant Temperature Sensor, part number 4954905. As near as I can tell it is located underneath the intake manifold on the driver's side cylinder head. The fault was:-. Connect temperature sensor to computer. Coolant Temp Sensor Lube Mobile, the Mobile Mechanics can diagnose and perform repairs on your car Coolant Temp Sensor. depend on the engine's temperature. This is usually close to or in the thermostat housing, which is at the end of the hose coming from the radiator. The thermostat needs to be opening and closing at the proper temperature levels and not sticking, and the water pump needs to be working so it can circulate the coolant thru the engine, radiator and heater core. This sensor mounts using 3/8 pipe and has a 2-wire connector. It also doesn't require any external calibration to provide typical accuracies of ±1°C at +25°C and ±2°C over the −40°C to +125°C temperature range. How Does a MAP Sensor Work? When the engine in your car is not working, the pressure in the intake chamber is the same as the barometric pressure outside. Needs an EGR coolant temp sensor. How do I check to verify the temperature sensor is operating properly on a 5045E trac My temperature gauge stopped working on my JD 5045E tractor recently and I need help to see if the temperature sensor is working properly. This blog ended up being pretty long as there is a lot of useful information to share on Pt100 sensors. They come equipped with sensors and gauges to help alert owners to potential problems or maintenance needs. P0116 Description. Most pro's test actual voltage coming out of the engine coolant temperature sensor. The TMP36 is a low voltage, precision centigrade temperature sensor. This happens because the PCM has increased fuel delivery to meet the fuel map for the indicated (not the actual) engine operating temperature. is located on the right rear in the block, just below the ignition coil. is in the very front by the radiator in the multiple outlet. engine coolant temperature sensor is faulty. See the diagram below for where to test voltage. The thermostat in most cars is about 2 inches (5 cm) in diameter. The engine coolant temperature sensor is located on the cylinder head, usually found beside or near the engine thermostat in the water jacket. The coolant temperature sensor on a Chevrolet engine is used by the vehicle's computer to determine how hot or cold the coolant flowing through the engine block is at any given time, so that the computer knows how to properly run the engine. The truck is burning coal heavy up to 40 mph. I loosen the sensor to finger tight, place a vacuum pump on the rad fill (or pressure reservoir) and just swap the old sensor for the new. If one is faulty, then this can seriously affect the idling of your car. The coolant sensor just operates the gauge or light on the dash and on the newer cars in some cases will also send that info to the computer in order for the computer to compare the information for a more. Coolant Temperature Sensor Basics. What do they do? Determine the exact temperature of the engine coolant. One of the things that will help you solve a ECT temperature problem is knowing how it works. 2 Throws a CEL and goes into limp mode on the way home yesterday. Oxygen sensors do this through a chemical reaction inside the sensor itself; in this article we will explain the evolution and application of this very important piece of the fuel injection puzzle. How it Works. But how does this car temperature sensor really work—and what's its purpose? How the Temperature Sensor Works. So I assumed it was the temp sensor. Gauge on dashboard unresponsive. Whether your BMW's coolant level is too low or the operating temperature is too high, these sensors send urgent information so you can react as necessary. (If the vehicle only has one sensor, it's a coolant temp sensor and provides the readings to both the gauge and computer. It monitors and because of the way it is wired into the system, sends electrical signals back to the engine control module that uses the data to adjust the fuel enrichment, ignition timing and other critical engine functions. Just did this job today and found some better ways to do it, over what I've read on some Audi sites so thought I'd publish my own guide. To help determining whether a coolant temperature sensor is functioning correctly, different possible deviations from the example signal are mentioned along with probable causes. These sensors come in many different forms and are used for a wide variety of purposes, from simple home use to extremely accurate and precise scientific use. You can test your Engine Coolant Temperature sensor in a pan of water on the stove with a meat thermometer and an ohmmeter. Temperature gauges are built into the car's instrument housing on the dashboard. The sensor modifies a voltage signal from the Engine Control Module (ECM). Get them at NAPA. The right interval will depend on a range of factors - from the age and condition of your car, to the type of driving you do most often and the variety of coolant/antifreeze in the reservoir. On that generation there's only one sensor unit that is used by both the engine control module and the temperature gauge. Join the rubber hoses together with a hose splice from Home Depot rather than plug them up. One is a coolant temperature sensor and the other is a coolant level sensor. This sensor is almost always ntc in design (negative temperature coefficient). However, most people don’t realize that the temperature sensor may be malfunctioning. When the sensor is bad you will notice a problem with the needle rising steadily. The O2 sensor works like a miniature generator and produces its own voltage when it gets hot. Generally speaking, Engine sensors are the electro-mechanical devices which monitor various engine parameters. Truck runs great with coolant sensor unplugged. The voltage signal, produced by the sensor, is passed to the ECU. This means that as temperature goes up resistance and voltage goes down or vise-versa. engine coolant temperature sensor is faulty. The thermostat needs to be opening and closing at the proper temperature levels and not sticking, and the water pump needs to be working so it can circulate the coolant thru the engine, radiator and heater core. I need some help troubleshooting the problem. i have a 92 gmc 1500 with 4. Nevada_545 said, "The coolant temp sender for the gauge has one wire, dark green. As the coil or spiral unwinds it pulls the linkage on the needle, which in turn shows a temperature reading on the gauge face. You can do that, but it's not a very accurate test. The CTS is immersed in the engine coolant and contains a variable resistor that usually operates on the NTC (Negative Temperature Coefficient) principle. The computer uses this and other inputs to calculate the correct amount of fuel delivered. How it Works. to put in an original equipment engine coolant temp sensor in and if this does not work I am putting it in the. still dont turn on replace fan assembly. Step 4 - Check the engine coolant temperature (ECT) sensor. Do Engine Coolant TTemp Sensor and Dash Temp Gauge work independently? Hello, I bought a 2004 BMW 325ci, it overheats, it had a dtc saying something about coolant temperature circuit or sensor, I cleared, and don't know the exact DTC number. Generally speaking, Engine sensors are the electro-mechanical devices which monitor various engine parameters. engine coolant temperature. asadi wrote: >Asking those more knowledgeable than I, I pose the following > >The 'Auto Zone' diagnostic trouble code was for the coolant temperature >sensor. operating temperature, the gauge rests at the mid-point of the temperature scale. circuit uses the same temperature sensor as the. Therefore; with a 180 degree water thermostat in the engine, and the probe installed next to the thermostat, the Water Temp gauge should read about 180 degrees under normal operating conditions. You can do it at home using a digital multimeter and a cooking thermometer. You still need to keep topping off the radiator until you get it repaired. What is the abbreviation for Coolant Temperature Sensor? What does CTS stand for? CTS abbreviation stands for Coolant Temperature Sensor. If the speedometer and tachometer are functioning properly, that leaves three other options. The coolant temperature sensor uses a “mushroom” shaped key way where it inserts into the sensors, while the open element intake air temperature sensor uses a “rectangular” connector key way. Now, with this special sensor, the engine will adjust itself so. I bought speedhut gauges that come with a temp sensor fitting into an 1/2" NPT adapter (two pieces on the left). Best Answer: Yes you can but it not do any good. Engine Coolant Temperature Sensors. What's interesting is that we let the hot coolant flow through the another heater core and make the air blow through it using blower, thus using this heat to keep ourselves warm in car in winters. As temperature rises resistance decreased and vise vera. The coolant temperature sensor, abbreviated as CTS, in your car is an important device that enables the control unit to give alerts if the engine is. Many late-model cars and trucks use electric radiator fans. it only has one wire. It doesn't touch the fluid in the reservoir so how does it detect if the coolant level is low? (see phot. The ECM controls the fan for engine temp and sends a signal to the cluster and to the climate control if car has ECC. You can test your Engine Coolant Temperature sensor in a pan of water on the stove with a meat thermometer and an ohmmeter. And though high heat can be caused by numerous things, it's the job of the EOT sensor and the engine coolant temp sensor to detect these conditions and let you know about it before things get to that critical stage. Richard Lloyd 2,356,128 views. So the thermostat, be it a standard-temperature OE model or a low-temperature design, not only helps the engine warm up quickly and sets the point at which coolant is allowed to flow more freely. doesn't appear contaminated with coolant. If your coolant temperature consistently runs higher than 100 °C, it's time to start looking for problems. Also is there one or two? reason why I ask about one or two is because many vehicles use 2 sensors, 1 sensor, and one sender for the gauge. The O2 sensor works like a miniature generator and produces its own voltage when it gets hot. If there is no bung ont he crossover or you cant find the sender then someone has replaced the coolant crossover. Obviously if the coolant temp sensor says it's 190 degrees out but the air is only 30 degrees something is up. there are two types in use. Steps to Test a Coolant Temperature Sensor. Do not confuse this sending unit with the other switches or sensors used to signal the engine control unit or air conditioning regarding temperature of the coolant. Steve83 wrote:The one up front is the Engine Coolant Temp sensor (ECT), which is strictly for the computer. The first is it looking down near the steering shaft. The coolant temperature sensor is located on the passenger side radiator tank about 1/3 of the way down. If the engine is cold, the coolant sensor will tell the CPU to perform a closed loop operation and raise the idle speed to quickly heat up the engine. But anyways im getting a check engine light for the coolant temp sensor (p0125) and also my gauge does not work on my dash. Many forums suggest this is due to a faulty “Blue” temperature sensor. Your radiator fan may not be turning on due to a blown fuse, an issue with the wiring, or a failed coolant temperature sensor. 3 engine's major components. If the temperature rises up the sensor is reduces the voltage of the sensor. The CTS is immersed in the engine coolant and contains a variable resistor that usually operates on the NTC (Negative Temperature Coefficient) principle. Various Engine Sensors Types of Engine Sensors: A thermocouple sensor is a temperature measuring device. QUOTE=toxicwaste29;477227]Here is a short brief write up for replacing the coolant temp sensor on a 3. Assuming this is not a diesel engine. The viscosity of the oil is optimized for just this temperature. Now on my 91, I can't seem to find this 'other' sensor (not that it's a big deal) but I'm curious to how the computer gets the engine coolant temperature without this sensor. But what does this sensor do, and why does it matter?. The coolant temp sensor is usually located on the intake manifold or the water inlet to the engine. As temperature rises resistance decreased and vise vera. Coolant Temp Sensor for all 6. The core or element of the sensor is Zirconia ceramic with a thin layer of platinum. Usually a problem with the coolant temperature sensor will cause a few symptoms that alert the driver of a potential problem that should be thoroughly inspected. A compromise is a wall temperature of 90 °C. This is the coolant temp sensor for most later TDIs, including PD engined A4 chassis cars. To fix the coolant sensor: Behind the engine block on the driver's side lives the sensor. It will also alert you for if the temperature within the system is rising for some reason. Engine Coolant Temperature Sensor (ECT) Tech Tip: After sitting overnight, the Engine Coolant Temperature should equal the air temperature. The coolant level sensor is the electronic sensor that is responsible for measuring the coolant level of your engine. This is an analog device evaluates the coolant's temperature and sends this information to the engine computer. A while back I wrote about thermocouples, so I was thinking it's time to write about RTD temperature sensors, especially on the Pt100 sensor which is a very common temperature sensor in the process industry. NOTE: THIS IS A BAM (225) ENGINE SENSOR PLEASE CHECK IF YOURS IS DIFFERENT APX (225) IS A DIFFERENT SENSOR PART NUMBER. You seemed to confirm that noting that the temp gauge reading was the same with the swapped location. The sensor keeps tabs on the operating temperature and alerts the on-car computer when there's a potential problem. A coolant temperature sensor (CTS) (also known as an ECT sensor or ECTS (engine coolant temperature sensor) is used to measure the temperature of the coolant/antifreeze mix in the cooling system, giving an indication of how much heat the engine is giving off. The ECM uses temperature data from the coolant temperature sensor to: vary injector pulse width, increasing on-time for a richer mixture when the engine is cold, and decreasing on-time as the engine warms up; increase idle speed when the engine is cold, to prevent stalling; and turn the electric cooling fan on and off. • Engine coolant temperature sensor • The sensor for the intake manifold air temperature • The sensor for the intake manifold pressure • Speed/timing sensors • Throttle position sensor At engine start-up, the ECM determines the top center position of the number 1 cylinder from the speed/timing sensors. After looking up other threads on this page my cars symptoms matched as well. 2 8v mk2 punto i keep getting the same problem over and over againPO115 engine coolant temperature circuit malfunction i have changed the coolant sensor 3 General: Coolant temperature sensor fault PO115 - The FIAT Forum. Once the engine reaches its operating temperature (generally about 200 degrees F, 95 degrees C), the thermostat opens. These products are shortlisted based on the overall star rating and the number of customer reviews received by each product in the store, and are refreshed regularly. Spray some good contact cleaner on it and fire it up and see if that fixed it. I replaced the sensor and it didn't change anything. The engine coolant temperature (ECT) sensor test is simple and can help you fix your car faster. So if you want to test this, the best thing to do is get an OBDII scanner and go out in an OBDII car and monitor the ECT sensor and watch how coolant temps regulate and spike as load changes. Get them at NAPA. The thermostat needs to be opening and closing at the proper temperature levels and not sticking, and the water pump needs to be working so it can circulate the coolant thru the engine, radiator and heater core. An engine coolant temperature sensor measures coolant temperature. What is Engine Coolant / Antifreeze This guide explains ‘What is engine coolant / antifreeze, what it does, why you should use it, what type of antifreeze / coolant to use and where to put it’. Does the ECT sensor send information to the ECM only? or does it also send information to the guage? Can the ECT work sporadically? or is it an all or nothing kind of deal?. if try to fount the coolant temperature sensor (CTS)(Green color) Please star by looking around the [Engine Head] AFTER REMOVING THE TOP COVERS in 4 Cly. The coolant temperature sensor is a variable resistor whose resistance changes as a function of temperature. Terminal Type: Flat Pin. This "thermistor" works just like a coolant temperature sensor. It has a square back and faces toward the engine and is held in place by a spring clip. Usually a problem with the coolant temperature sensor will cause a few symptoms that alert the driver of a potential problem that should be thoroughly inspected. If the fan does not turn on, you will need to replace it. Coolant Temperature Sensor monitors the temperature of the water in the engine. As noted above, ground the single connector with key on and the temp gauge should shoot quickly to the red if the circuit is intact. Here is the location of the coolant temp. The engine coolant temperature (ECT) sensor test is simple and can help you fix your car faster. If temperature gauge does not indicate cold, go to step 3). It is recommend that you use a 1/4-inch ratchet with a long socket on it so you don't torque it too much. The sensor modifies a voltage signal from the Engine Control Module (ECM). Replacing the coolant temperature sensor on your SLK230 is a relatively easy job and can be accomplished in under an hour. The ECT works by changing its internal resistance according to coolant temperature and therefore also changing the voltage drop across itself. If those don't solve the problem, try replacing the coolant temperature sensor. This product is designed to be placed inline on any hose. Also is there one or two? reason why I ask about one or two is because many vehicles use 2 sensors, 1 sensor, and one sender for the gauge. Compare the most helpful customer reviews of the best rated products in our Automotive Replacement Coolant Temperature Sensors store. temperature gauge not working. It measures and controls the temperature such as in the case of Engine Coolant Temperature. As the coolant warms up the alcohol in the Bourdon tube expands. I would suspect a faulty sensor, but it was replaced. TEMPERATURE SENSOR PRODUCT DATA COOLANT TEMPERATURE SENSOR PART NUMBER 12146312 FEATURES • Design for Manufacturability • Cost Effective • Robust Design • Few Components & Assembly Processes • Thermistor Technology • 100% Calibration Certified Thermal & Electrical Properties Mechanical Characteristics. The float may have become stuck, the magnet of the switch may have fallen off, or the wiring for the sensor may be. But how does this car temperature sensor really work—and what's its purpose? How the Temperature Sensor Works. Now on my 91, I can't seem to find this 'other' sensor (not that it's a big deal) but I'm curious to how the computer gets the engine coolant temperature without this sensor. If you get a sensor from the dealer it will have some red sealer on the threads that makes it ready to install. i have a coolant temperature sensor (the one that's in the thermostat housing) that is not connected to anything. How it Works. Hello All, I have a keyless remote that does not work. How does a CTS work? The CTS is a thermistor that measures the temperature and sends a signal back to the ECU. This is the latest DS18B20 1-Wire digital temperature sensor from Maxim IC. The sensor itself is a thermocouple, in which electrical resistance changes relative to temperature. Do yourself a favor and do NOT replace the factory overtemp switch with another one of the same temp. Nevada_545 said, "The coolant temp sender for the gauge has one wire, dark green. Coolant Temperature Sensor Basics. If your coolant temp sensor is responding as it usually does, then there is coolant making contact with it. Assuming this is not a diesel engine. As near as I can tell it is located underneath the intake manifold on the driver's side cylinder head. Just thought I would share this, I replaced the coolant temp sensor the one that is wired to the Engine management system in my VS ute yesterday. It is usually installed in the coolant reservoir or radiator, and measures the amount of coolant in the system to make sure that it is always at the proper level. Ok does this mean I check out the one at the back of the engine? I need to check the one that controls the gauge inside on the dash. Each sensor has a unique 64-Bit Serial number etched into it - allows for a huge number of sensors to be used on one data bus. GM 2 Wire Coolant Temperature Sensor Connector $11. This is vital information for the PCM because many control functions vary with temperature. The right interval will depend on a range of factors - from the age and condition of your car, to the type of driving you do most often and the variety of coolant/antifreeze in the reservoir. But does read low coolant on the readout until it get up to around 135 degrees. It can help the control unit in your engine system to detect when the coolant is not functioning well and your vehicle is overheating. The coolant temperature sensor checks how hot the engine's coolant is running. It does this through changing resistance and sends this information to the onboard computer. During hot and cool driving the thermostat will open and close as you drive to regulate the engine coolant temperature. is normally by the back side of the fire wall 6Cly. That switch is the "kiss your engine goodbye light" and you need to be told it is getting too hot before you reach that 244 degree threashold. Refill cooling system. I bought speedhut gauges that come with a temp sensor fitting into an 1/2" NPT adapter (two pieces on the left). Not to mention the moisture in the air is draining onto your bathroom floor. The ECM uses temperature data from the coolant temperature sensor to: vary injector pulse width, increasing on-time for a richer mixture when the engine is cold, and decreasing on-time as the engine warms up; increase idle speed when the engine is cold, to prevent stalling; and turn the electric cooling fan on and off. Obviously if the coolant temp sensor says it's 190 degrees out but the air is only 30 degrees something is up. Connect temperature sensor to computer. The temperature that the sensor reads is then sent to the on-board computer or engine control system as a signal. If temperature gauge indicates cold, go to next step. Most modern vehicles use two engine coolant temperature sensors, one for the gauge and and one for the computer. That means a leaky heater circuit gets looped rather than just plugged up. How Do Thermoelectric Coolers (TEC) Work? | II-VI Marlow Thermoelectric coolers work according to the Peltier effect. The CTS is immersed in the engine coolant and contains a variable resistor that usually operates on the NTC (Negative Temperature Coefficient) principle. You can troubleshoot coolant temperature sensor problems by watching the temperature gauge on your vehicle. I got this code PO115 which is Coolant Temp Sensor Circuit But the code reader did not really tell me what Sensor. , and on the 6 cyl. Your radiator fan may not be turning on due to a blown fuse, an issue with the wiring, or a failed coolant temperature sensor. Replacing the coolant temperature sensor on your SLK230 is a relatively easy job and can be accomplished in under an hour. 6 190E Coolant Temperature Sensor Wiring i have some questions about the coolant temperature sensor on the m103 2. Usually, these other units are mounted near the coolant temperature sensor used for engine control. It doesn't touch the fluid in the reservoir so how does it detect if the coolant level is low? (see phot. There could be a problem in the wiring to the PCM.