To begin with the engine temp sensor and the coolant temp sensor are different.
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.
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.
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.
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.
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 sensor works with the vehicle’s ECU, continually monitoring the coolant temperature to make sure the engine is running at the optimum temperature.
To get an accurate reading of the current engine temperature, the ECU sends a regulated voltage to the CTS. The resistance of the sensor varies with temperature, this is how the ECU can monitor temperature changes. The ECU uses this reading to calculate the coolant temperature, and from there adjusts the fuel injection, fuel mix, and ignition timing, and controls when the electric cooling fan is switched on and off. This information is also used to send an accurate reading of the engine temperature to a gauge on the dashboard.
Some vehicle ( certain Nissans ) are equipped with both sensors, one to handle the dashboard function while the other works in conjunction with the ECU for engine management.
Btw with your take, ect fooling the ecm should rather take out fuel when it sense the car is running hot but not adding ( run rich). Ecm run rich at cold start not operating temperature.
Ummmmm, think you need to read this.
By changing the amount of fuel in the mixture, you are changing the types of collisions that can occur. And it’s not exactly straight forward, but some molecules are better at exchanging energy with others. To make the fuel molecule fall apart, they need to collide with other fuel molecules with some energy of with other oxygen molecules with more energy. <font color="red]If you add more than the usual amount of oxygen (run lean), you also need to make that oxygen hotter[/color] so the molecules have more energy when they collide and can make the fuel vibrate hard enough to fall apart. Conversely, if you run fuel-rich, you have more fuel molecules that can collide with one another and fall apart, [color=red”>but fewer oxygen molecules for them to combine with and give off heat. This (and some other effects) makes the final flame temperature lower.
Can you educate me a bit here ?