На что влияет датчик охлаждающей температуры жидкости: Чем опасна поломка датчика температуры охлаждающей жидкости

Датчик температуры охлаждающей жидкости: 7 признаков неисправности.

Содержание статьи

Что такое датчик температуры охлаждающей жидкости (ДТОЖ)

Назначение

Датчиков в автомобиле существует множество. Все они контролируют работу различных систем автомобиля и его двигателя. Если датчики выдают некорректные показания, то работоспособность автомобиля ставится под угрозу. То же самое можно сказать и о ДТОЖ.

ДТОЖ предназначен для поддержания стабильной работы двигателя внутреннего сгорания (далее ДВС). За счёт ДТОЖ автомобиль быстрее прогревается и меньше достигает слишком высоких температур. Некоторые путают ДТОЖ с датчиком указателя температуры охлаждающей жидкости. Это — два совершенно разных прибора.

ДТОЖ предоставляет свои показания электронному блоку управления двигателем, а второй датчик уведомляет водителя о температуре рабочей жидкости в системе охлаждения. Выход из строя второго датчика не приводит к серьёзным последствиям в отличие от первого.

Говоря о ДТОЖ, следует также упомянуть о назначении системы охлаждения двигателя, так как работа этих двух агрегатов неразрывно связана. Чаще всего используется жидкостная система охлаждения, главной задачей которой является отведение тепла от двигателя.

Кроме этого, система также несёт функции охлаждения масла в системе смазки, воздуха, который циркулирует в системе турбонаддува, отработавших газов, рабочей жидкости коробки передач. Также у неё имеется функция нагревания воздуха в системах вентиляции и отопления.

Работа столь важной системы автомобиля напрямую зависит от такой маленькой детали, как ДТОЖ. Поэтому не стоит недооценивать датчик и пренебрегать его диагностикой.

Устройство и принцип работы

ДТОЖ по своему устройству напоминает резистор. Конструкция датчика предусматривает изменение его сопротивления электрическому току при колебаниях температуры окружающей среды. Эти изменения фиксируются и используется для подачи команд ДВС.

Предшественниками современных ДТОЖ были термореле. Термореле были установлены в системах впрыска. Когда контакты находились в открытом положении, двигатель нагревался. Если контакт замыкался — значит двигатель уже достаточно прогрелся (достиг рабочей температуры).

В основе устройства современных ДТОЖ лежит термистор, который и устанавливает зависимость сопротивления от температуры. В основе термистора лежат оксиды кобальта и никеля. При росте температуры в этих веществах растёт количество свободных электронов, за счёт чего и падает сопротивление.

Некоторые термисторы в ДТОЖ характеризуются отрицательным температурным коэффициентом. При этом термистор выдаёт максимальные показатели при холодном двигателе. На датчик подаётся напряжение около 5 вольт. После этого по мере прогревания силового агрегата сопротивление понижается. Электронный блок управления (далее ЭБУ) двигателем следит за изменением напряжения и рассчитывает температуру жидкости. После нагревания двигателя ЭБУ начинает обеднять топливную смесь. Неисправность ДТОЖ может также привести к ошибочному обогащению топливной смеси. Результатом этого будет усиленное загрязнение атмосферы и преждевременный выход из строя свечей.

Если количество оборотов двигателя при запуске будет недостаточным — может произойти остановка двигателя. Уплывающая команда ЭБУ на повышение оборотов может это предотвратить. Для поддержания управляемости в процессе запуска двигателя клапан рециркуляции должен быть закрыт до тех пор, пока двигатель не достигнет своей установленной рабочей температуры.

Здесь результатом неисправности ДТОЖ будут плавающие обороты двигателя. Двигатель при этом тоже может остановиться. Угол зажигания также зависит от функционирования датчика, так как этот параметр регулируется системой. Выброс вредных газов при такой регулировке значительно снижается. В конечном итоге мощность и тяга двигателя, а также уровень потребления топлива напрямую зависят от работы ДТОЖ.

Таким образом, ДТОЖ очень важен для корректного функционирования автомобиля.

Место установки датчика

Где находится датчик температуры охлаждающей жидкости в автомобиле? У разных моделей место установки ДТОЖ различается. Чаще всего он устанавливается в головке блока цилиндров возле корпуса термостата или на нём. Обязательным является расположение датчика возле отводящего патрубка, по которому охлаждающая жидкость поступает обратно в радиатор. Такое расположение необходимо для точности передачи данных в ЭБУ.

Виды датчиков

ДТОЖ классифицируются по принципу зависимости от изменения сопротивления:

1. ДТОЖ с отрицательным температурным коэффициентом. Принцип работы таких датчиков заключается в том, что внутреннее сопротивление уменьшается по мере роста температуры и наоборот.
2. ДТОЖ с положительным температурным коэффициентом. Принцип работы противоположен предыдущей разновидности датчиков. В этих датчиках сопротивление увеличивается при росте температуры.

В настоящее время наиболее популярен первый тип датчиков. Иногда в автомобиле встречаются сразу два датчика: основной и дополнительный.

Основной датчик выполняет функцию передачи значения температуры на ЭБУ, а дополнительный — включение вентилятора.

Неисправности ДТОЖ и их признаки

Принято считать, что ДТОЖ достаточно надёжен из-за своей нехитрой конструкции. Однако рано или поздно практически каждый агрегат автомобиля подвергается износу. В случает с ДТОЖ имеет место быть нарушение градуировки. Такое нарушение приводит к незапланированному изменению сопротивления и некорректной работе ЭБУ.

Самым явным признаком выхода из строя ДТОЖ является отсутствие включения в работу вентилятора во время того, как температура повышается выше установленных значений.

Этот показатель не считается достоверным, если в автомобиле присутствуют одновременно основной и дополнительный датчики. В этом случае на неисправность точнее укажет окисление проводки или выход из строя дополнительного датчика. Основные признаки неисправности ДТОЖ следующие:

• падение оборотов двигателя или самопроизвольная его остановка на холостом ходу;
• более длительное время прогрева автомобиля;
• учащённый выход двигателя за рамки оптимального температурного режима во время работы;
• увеличенный расход топлива;
• снижение контроля над автомобилем у водителя;
• дым из выхлопной трубы приобретает чёрный оттенок;
• нарушение стабильности работы двигателя.

Кроме этого иногда возможны детонационные постукивания в двигателе. На некоторых старых моделях автомобилей есть специальный контроллер. Когда стрелка этого контроллера выходит за пределы критической зоны, автомобиль необходимо немедленно остановить. В этом случае порой тоже имеет место неисправность ДТОЖ. А в более современных моделях о перегреве двигателя водителей уведомляет бортовой компьютер. Но такое сообщение не всегда указывает на неисправность именно датчика. Часто это происходит из-за обрыва проводки и её окисления.

Причины возникновения неисправностей

Поломка ДТОЖ достаточно редко беспокоит автолюбителей вследствие своей простой конструкции. Но причин выхода из строя всё же достаточно. Использование некачественного антифриза и моторного масла приводит к разрушению поверхности ДТОЖ. Чувствительный элемент датчика может покрываться осадком в виде кристаллов. Причина может крыться и в производственном браке. Не стоит покупать ДТОЖ на барахолках и различных дешёвых рынках автозапчастей. ДТОЖ, купленный на таком рынке, зачастую не будет отвечать заявленным параметрам и малейшие повреждения приведут к выходу датчика из строя. Утечка антифриза может привести к износу прокладки. Скачок напряжения в бортэлектросети и коррозия контактов также могут быть причиной выхода из строя датчика.

90000 Symptoms of a Bad or Failing Coolant Temperature Switch (Sensor) 90001 90002 The coolant temperature sensor, also known as the coolant temperature switch, is an engine management system sensor that is used to monitor the temperature of the engine’s coolant. Most coolant temperature sensors operate using electrical resistance to measure the temperature of the coolant. This signal is then sent to the computer so that changes can be made to the engine’s timing and fuel calculations for optimal performance, as engines require more fuel when they are cold, and less fuel when they are fully warmed up.The computer will also scale back engine performance settings if it detects that the engine temperature is too high, in order to protect the engine from possible damage due to overheating. 90003 90002 Because temperature plays such a vital role in engine performance calculations, any problem with the coolant temperature sensor can quickly translate into an engine performance issues. 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.90003 90006 1. Poor fuel economy 90007 90002 One of the first symptoms associated with a problem with the coolant temperature sensor is poor fuel economy. If the coolant temperature sensor goes bad it can send a false signal to the computer and throw off the fuel and timing calculations. It is not uncommon for the coolant temperature sensor to fail and send a permanently cold signal to the computer. This will cause the computer to think the engine is cold, even when it is not, and as a result will use more fuel than necessary.This will reduce fuel economy, and may hinder engine performance. 90003 90006 2. Black smoke from engine 90007 90002 Another symptom of a possible problem with the coolant temperature sensor is black smoke from the vehicle’s exhaust. If the coolant temperature sensor fails and sends a cold signal to the computer, this can confuse the computer and cause it to unnecessarily enrich the fuel mixture. If the fuel mixture becomes excessively rich to the point where the fuel can not be adequately burned in the combustion chamber, it will burn up in the exhaust pipes and cause black smoke.In severe cases, the black smoke may be considerable enough to warrant not driving the vehicle. 90003 90006 3. Overheating engine 90007 90002 Another symptom of a problem with the coolant temperature sensor is an overheating engine. The coolant temperature sensor can also fail in a manner that causes it to send a permanently hot signal. This can cause the computer to incorrectly compensate for a lean signal, which can result in overheating, and even misfires or engine ping. 90003 90006 4.Check Engine Light comes on 90007 90002 An illuminated Check Engine Light is another symptom of a potential problem with the coolant temperature sensor. For some vehicles the computer will set off a Check Engine Light if it detects a problem with the sensor’s signal or circuit. The Check Engine Light will remain on until the issue is addressed. 90003 90002 The coolant temperature sensor is one of the most important engine management sensors, as its reading plays a key role in calculations which affect engine performance.For this reason, if you suspect that your coolant temperature sensor is having an issue, have the vehicle inspected by a professional technician from YourMechanic. They will be able to diagnose your vehicle and determine if you need a coolant temperature switch replacement. 90003 .90000 Engine Coolant Sensors 90001 90002 The engine coolant temperature (ECT) sensor is a relatively simple sensor that monitors the internal temperature of the engine. Coolant inside the engine block and cylinder head (s) absorbs heat from the cylinders when the engine is running. The coolant sensor detects the change in temperature and signals the Powertrain Control Module (PCM) so it can tell if the engine is cold, warming up, at normal operating temperature or overheating. 90003 90002 The coolant sensor is extremely important because the sensor’s input to the PCM affects the operating strategy of the entire engine management system.That’s why the coolant sensor is often called the «master» sensor. 90003 90002 Many of the fuel, ignition, emissions and drivetrain functions handled by the PCM are affected by the engine’s operating temperature. A different operating strategy is used when the engine is cold than when it is warm. This is done to improve cold driveability, idle quality and emissions. Consequently, if the coolant sensor fails or is giving the PCM a false reading, it can upset a lot of things. 90003 90008 HOW THE COOLANT SENSOR AFFECTS ENGINE OPERATION 90009 90002 Input from the coolant sensor may be used by the PCM for any or all of the following control functions: 90003 90002 * Start up fuel enrichment on fuel injected engines.When the PCM receives a cold signal from the coolant sensor, it increases injector pulse width (on time) to create a richer fuel mixture. This improves idle quality and prevents hesitation while the cold engine is warming up. As the engine approaches normal operating temperature, the PCM leans out the fuel mixture to reduce emissions and fuel consumption. A faulty coolant sensor that always reads cold may cause the fuel control system to run rich, pollute and waste fuel. A coolant sensor that always reads hot may cause cold driveability problems such as stalling, hesitation and rough idle.90003 90002 * Spark advance and retard. Spark advance is often limited for emission purposes until the engine reaches normal operating temperature. This also affects engine performance and fuel economy. 90003 90002 * Exhaust gas recirculation (EGR) during warm-up. The PCM will not allow the EGR valve to open until the engine has warmed up to improve driveability. If EGR is allowed while the engine is still cold, it may cause a rough idle, stalling and / or hesitation. 90003 90002 * Evaporative emissions control canister purge.Fuel vapors stored in the charcoal canister are not purged until the engine is warm to prevent driveability problems. 90003 90002 * Open / closed loop feedback control of the air / fuel mixture. The PCM may ignore the oxygen sensor rich / lean feedback signal until the coolant reaches a certain temperature. While the engine is cold, the PCM will remain in «open loop» and keep the fuel mixture rich to improve idle quality and cold driveability. If the PCM fails to go into «closed loop» once the engine is warm, the fuel mixture will be too rich causing the engine to pollute and waste gas.This condition may also lead to spark plug fouling. 90003 90002 * Idle speed during warm-up. The PCM will usually increase idle speed when a cold engine is first started to prevent stalling and improve idle quality. 90003 90002 * Transmission torque converter clutch lockup during warm-up. The PCM may not lockup up the torque converter until the engine has warmed up to improve cold driveability. 90003 90002 * Operation of the electric cooling fan. The PCM will cycle the cooling fan on and off to regulate engine cooling using input from the coolant sensor.This job is extremely important to prevent engine overheating. Note: On some vehicles, a separate coolant sensor or fan switch may be used for the cooling fan circuit only. 90003 90008 TYPES OF COOLANT SENSORS 90009 90002 Most coolant sensors are «thermistors» that change resistance as the temperature of the coolant changes. Most are the «NTC» (Negative Temperature Coefficient) type where resistance drops as the temperature goes up. With this type of sensor, resistance is high when the engine is cold.As the engine warms up, the internal resistance of the sensor drops until it reaches a minimum value when the engine is at normal operating temperature. 90003 90032 90002 A typical GM coolant sensor, for example, may have around 10,000 ohms resistance at 32 degrees F and drop to under 200 ohms when the engine is hot (200 degrees). A Ford coolant sensor, by comparison, may read 95,000 ohms at 32 degrees and drop to 2,300 ohms at 200 degrees. 90003 90002 Resistance specifications will vary depending on the application, so any sensor that does not read within its specified range should be replaced.90003 90002 Coolant sensors have two wires (input and return). A 5-volt reference voltage signal is sent from the PCM to the sensor. The amount of resistance in the sensor reduces the voltage signal that then returns to the PCM. The PCM then calculates coolant temperature based on the voltage value of the return signal. This number can be displayed on a scan tool, and may also be used by the instrument panel cluster or driver information center to display the temperature reading of the coolant.90003 90002 On some applications, a «dual range» coolant temperature sensor may be used. When the coolant reaches a certain temperature, the PCM changes the reference voltage to the sensor so it can read the coolant temperature with higher accuracy (higher resolution). 90003 90002 On some older vehicles, a different type of coolant sensor may be used. Some of these are essentially an on / off switch that opens or closes at a predetermined temperature. The sensor may be wired directly to a relay to turn the electric cooling fan on and off, or it may send a signal to a warning light on the instrument panel.These older coolant sensors are typically single wire sensors. On other older applications, a single wire variable resistor temperature sensor that grounds through the threads may be used to send a temperature signal to a gauge on the instrument panel. These are typically called temperature «senders» rather than sensors. 90003 90008 COOLANT SENSOR LOCATION 90009 90002 The coolant sensor is typically located near the thermostat housing in the intake manifold. On a few vehicles, the coolant sensor may be located in the cylinder head, or there may be two coolant sensors (one for each cylinder bank in a V6 or V8 engine) or one for the PCM and a second for the cooling fan.90003 90002 The sensor is positioned so the tip will be in direct contact with the coolant. This is essential to produce a reliable signal. If the coolant level is low, it may prevent the coolant sensor from reading accurately. 90003 90008 COOLANT SENSOR SYMPTOMS 90009 90002 Because of the coolant sensor’s central role in triggering so many engine functions, a faulty sensor (or sensor circuit) will often cause cold driveability and emission problems. A bad coolant sensor can also cause a noticeable increase in fuel consumption, and it may cause a vehicle to fail an emissions test if it prevents the engine management system from going into closed loop.90003 90002 Keep in mind that many coolant sensor problems are more often due to wiring faults and loose or corroded connectors than failure of the sensor itself. 90003 90002 The coolant sensor’s impact on the engine management system, cold driveability, emissions and fuel economy can also be influenced by the thermostat. If the thermostat is stuck open, the engine will be slow to warm up and the coolant sensor will read low. Or, if someone installed the wrong thermostat for the application or removed the thermostat altogether, it will prevent the engine from reaching normal operating temperature and cause the coolant sensor to read low.90003 90002 A faulty coolant sensor may also cause the engine to overheat if it fails to energize the cooling fan relay when the engine gets hot. 90003 90002 A faulty coolant sensor may also cause inaccurate coolant temperature gauge readings on the instrument panel. 90003 90008 COOLANT SENSOR DIAGNOSTIC FAULT CODES 90009 90002 On 1996 and newer vehicles with OBD II onboard diagnostic systems, a faulty coolant sensor may prevent some of the system monitors from running.This will prevent the vehicle from passing an OBD II emissions test because the test can not be done unless all the required system monitors have run and passed. 90003 90002 The OBD II system should catch the fault, turn on the Check Engine Light or Malfunction Indicator Lamp (MIL), and set one of the following diagnostic trouble codes: 90003 90002 90068 P0115 …. Engine Coolant Temperature Circuit 90032 P0116 …. Engine Coolant Temperature Circuit Range / Performance 90032 P0117…. Engine Coolant Temperature Circuit Low Input 90032 P0118 …. Engine Coolant Temperature Circuit High Input 90032 P0119 …. Engine Coolant Temperature Circuit Intermittent 90032 90074 90003 90002 On older pre-OBD II vehicles, the Check Engine light may come on if the coolant sensor is shorted, open or is reading out of range. GM coolant sensor codes include codes 14 & 15, Ford codes are 21, 51 & 81, and Chrysler codes are 17 & 22. 90003 90008 COOLANT SENSOR DIAGNOSIS 90009 90002 A visual inspection of the coolant sensor will sometimes reveal a problem such as severe corrosion around the terminal, a crack in the sensor, or coolant leaks around the sensor.But in most cases, the only way to know if the coolant sensor is good or bad is to measure its resistance and voltage readings. 90003 90002 On vehicle systems that provide direct access to sensor data with a scan tool, the coolant sensor’s output can usually be displayed in degrees Centigrade (C) or Fahrenheit (F). The coolant sensor should read low (or ambient temperature) when the engine is cold, and high (around 200 degrees) when the engine is hot. No change in the reading or a reading that obviously does not match engine temperature would indicate a faulty sensor or a wiring problem.90003 90002 The internal resistance of a coolant sensor can also be checked with an ohmmeter or DVOM (digital volt ohm meter) and compared to specifications. If the sensor is open, shorted or reads out of range, it must be replaced. 90003 90002 If the resistance of a coolant sensor is within specifications and changes as engine temperature changes, but the engine is not going into closed loop, the fault is in the wiring or PCM. Further diagnosis will be needed to isolate the problem before any parts are replaced.90003 90002 One trick here is to use a sensor simulator tool to feed a simulated temperature reading through the sensor’s wiring harness to the PCM. If the wiring continuity is good but the PCM fails to go into closed loop when you send it a «hot coolant» signal, the problem is in the PCM. 90003 90008 COOLANT SENSOR VOLTAGE CHECKS 90009 90002 You can also use a voltmeter or digital storage oscilloscope (DSO) to check the sensor’s output. Specs vary, but generally a cold coolant sensor will read somewhere around 3 volts.As the engine warms up and reaches operating temperature, the voltage drop should gradually decrease down to about 1.2 to 0.5 volts. If you’re using a scope to display the voltage signal, you should get a trace that gradually slopes from 3 volts down to 1.2 to 0.5 volts in three to five minutes (or however long it normally takes the engine to reach normal operating temperature) . 90003 90002 If the voltage drop across the coolant sensor reads at or near 5 volts, it means the sensor is open or it has lost its ground connection.If the voltage is close to zero, the sensor is shorted or it has lost its reference voltage. 90003 90002 When working on тисяча дев’ятсот вісімдесят п’ять and up Chrysler products, watch out for a sudden voltage increase as the engine warms up. This is normal and is produced by a 1000 ohm resistor that switches into the coolant sensor circuit when the sensor’s voltage drops to about 1.25 volts. This causes the voltage to jump back up to about 3.7 volts, where it again continues to drop until it reaches a fully warmed up value of about 2.0 volts. 90003 90002 Sometimes a coolant sensor will suddenly go open or short when it reaches a certain temperature. If your voltmeter has a «minimum / maximum» function, you can catch sudden voltage fluctuations while the sensor is warming up. If you are viewing the voltage pattern on a scope, a short will appear as a sudden drop or dip in the trace to zero volts. An open would make the trace jump up to the VRef voltage line (5 volts). 90003 90002 If the coolant sensor reads normally when cold (high resistance and 3 or more volts), but never seems to reach normal temperature it could be telling the truth! An open thermostat or the wrong thermostat may be preventing the coolant from reaching its normal operating temperature.90003 90008 COOLANT SENSOR REPLACEMENT 90009 90002 Most coolant sensors are not replaced unless they have failed. A coolant sensor that is shorted, open or reading out of range obviously can not provide a reliable temperature signal and must be replaced for the engine management system to function properly. But many experts also recommend installing a new coolant sensor if you are replacing or rebuilding an engine. Why? Because coolant sensors can deteriorate with age and may not read as accurately as they did when they were new.Installing a new sensor can eliminate a lot of potential problems down the road. 90003 90002 It is also a good idea to replace the coolant sensor and thermostat if the engine has experienced a case of severe overheating. Abnormally high engine temperatures can damage these components and may cause them to misbehave or fail prematurely. 90003 90002 Replacing a coolant sensor requires draining some of the coolant from the cooling system. You do not have to drain the entire radiator.Just open the drain valve and let out enough coolant so the coolant level in the engine is below the sensor. 90003 90002 This would be a good time to check the condition of the coolant, and to replace it if the coolant is more than three years old (conventional coolant) or five years old (long life coolant). A coolant change and a flush would also be a good idea if the coolant shows any signs of contamination. 90003 90002 The threads on the coolant sensor may be pre-coated with sealer to prevent coolant leaks.Tighten the sensor carefully to prevent damage. 90003 90002 Once the new sensor has been installed, you can refill the cooling system. Make sure all the air is out of the cooling system. Air trapped under the thermostat may cause the engine to overheat or the coolant sensor to not read correctly. 90003 90008 Click Here to Download or Print This Article. 90009 90032 90119 90068 90121 90032 Click Here to Learn More about Sensor Guide 90074 90032 90125 A quick reference guide to basic sensor operation and testing.90126 90119 90032 90008 90130 Related Articles: 90009 Causes of Engine Overheating 90002 Electric Cooling Fan Relay Problems 90003 90002 Making Sense of Engine Sensors 90003 90002 Understanding Engine Management Systems 90003 90002 All About Onboard Diagnostics II (OBD II) 90003 90002 90141 Click Here to See More Carley Automotive Technical Articles 90003 90008 Need Factory Service Manual Information for Your Vehicle? 90009 Mitchell 1 DIY eautorepair manuals 90002 90003.90000 How Long Does a Coolant Temperature Switch (Sensor) Last? 90001 90002 The coolant temperature switch (CTS) provides you with alerts when the engine temperature is rising or when it is overheating. It is also called the coolant temperature sensor, and it is an important part of keeping you safe and your vehicle running well. 90003 90002 Coolant from inside the cylinder heads and engine block absorbs heat from the cylinders while your vehicle is running. The CTS detects these changes in temperatures and alerts the powertrain control module (PCM).The message the sensor sends to the PCM affects the overall operation of the engine because much of the fuel, emissions, ignition, and drivetrain functions are handled by the PCM. Therefore, these functions are affected by the operating temperature of the engine. 90003 90002 If the PCM gets a cold reading from the CTS, the injector pulse width is increased to create a richer fuel mixture. This prevents hesitation while the engine is warming up. Once the engine is warm, the PCM reduces the mixture to make it leaner.The PCM cycles the cooling fan on and off to make sure the engine stays cool and to prevent it from overheating. The PCM cycles this by using information from the coolant temperature sensor. 90003 90002 The coolant temperature switch can go bad over time, whether it is due to wear and tear, or an electrical issue. At some point, your coolant temperature switch may need to be replaced by a professional mechanic. 90003 90002 Since the CTS can go bad, you should be aware of the symptoms it gives off before it completely fails.90003 90002 Signs your coolant temperature switch needs to be replaced include: 90003 90014 90015 Poor fuel economy 90016 90015 Black smoke coming from the exhaust pipe 90016 90015 Trouble starting your vehicle even after reaching normal operating temperature 90016 90015 Your vehicle fails an emissions test 90016 90015 You vehicle is constantly overheating 90016 90015 The temperature sensor is not consistent and behaves erratically 90016 90015 Check Engine Light comes on 90016 90015 Engine stalls or has a rough idle 90016 90031 90002 The CTS is an important part of your vehicle, because without it, your engine will run poorly and overheat on a regular basis.Eventually, if left as is, the engine will go bad and the vehicle will become inoperable. 90003 .90000 How Coolant Temperature Sensors Work Explained Under 5 Minutes 90001 90002 A coolant temperature sensor sends feedback information to the computer 90003 90002 How Does it Work? 90003 90006 An engine coolant temperature sensor also described as an ECTS (electronic coolant temperature sensor) is designed to tell the car’s computer how hot the engine is running. This information is then used to make fine adjustments to the operating system designed into the computer which will affect engine performance.Adjustments are then made to the individual fuel injectors pulse width which is responsible for controlling fuel mixture and also control the cam timing and ignition advance. Together these three adjustments are the final result of the engine’s power output and fuel economy capabilities. 90007 90006 The car’s temperature gauge or temperature warning light is controlled by the computer which relies on the readings of the coolant sensor. If the sensor is malfunctioning the gauge reading will be too cold, too hot or the warning light will be on constantly.The coolant sensor’s location is designed to monitor the engines coolant temperature where the coolant is the hottest which is usually at the upper coolant hose outlet or in the cylinder head near the combustion chambers. The coolant temperature sensor is comprised of a metal housing filled with a composite which varies the resistance through its internal circuit as the engine temperature increases or decreases. 90007 90006 When there is a coolant leak or the engine has a blown head gasket the sensor can be fooled because of the air or exhaust trapped in the cooling system which the sensor can not read.This is why certain conditions can exist that will be puzzling to the car’s driver for example; it is obvious the engine is overheating due to the steam being produced from under the hood but the temperature gauge will read cold with no temperature warning light on. This is because the sensing part of the sensor does not have coolant around it so there is nothing to read. 90007 90006 SPONSORED LINKS 90007 90006 A coolant temperature switch was used in older cars to turn the engine temperature warning light on.This simple one wire temperature sender was also used to give feedback information to the temp gauge in the dash. Today’s coolant temp senders have two wires, one wire is feed a small amount of voltage from the computer while the second wiring is read by the computer and the engine temperature determined. 90007 90006 90017 90007 90006 A coolant sensor wiring connector is held in place using a safety clip. There is also a weather pack seal that is designed to keep moister from the sensors electrical connectors which will cause corrosion and will alter the sensors readings.If the sensor housing is cracked it will allow moisture into the electrical connections when this happens the coolant sensor should be replaced. 90007 90002 Get Questions? 90003 90006 If you have any engine coolant temperature sensor questions please visit our forum. If you need car repair advice, please ask our community of mechanics is happy to help you and it is always 100% free. 90007 90006 We hope you enjoyed this guide and video. We are creating a full set of car repair guides.Please subscribe to our 2CarPros YouTube channel and check back often for new videos which are uploaded almost every day. 90007 90006 SPONSORED LINKS 90007 90006 Article published 2019-01-22 90007 .