Types of Sensors Used In A Car Engine

Most of the modern cars which we see on the road nowadays are equipped with more electronics than we could possibly imagine. These new technologies which are coming in the cars are all controlled by ECU’s which stands for the Electronic Control Unit which is also known as the brain of the automobile. It gathers information from the sensors present in the car to keep a check on the various engine parameters so as to improve the car’s performance, reduce emissions, etc. It is also used to keep a check on working parts & notify us if anything fails.

Let us have a look at various sensors used in the car’s engine nowadays along with their working –

Boost Pressure Sensor

It is a sensor that is used to measure boost pressure in the pressure lines. It is generally located on pressure lines before a turbocharger or a supercharger.

Camshaft Sensor

It is a sensor that is used to measure the position of the camshaft. It is generally located on each camshaft. This sensor works simultaneously with the crankshaft sensor so as to provide information on the position of the cylinder with respect to TDC(Top-dead center) & BDC so as to adjust the opening & closing of the inlet and exhaust valves.

Coolant temperature Sensor

It is a sensor that is used to measure the temperature of the coolant. Sometimes it is mounted high in the engine compartment on a coolant hose or screwed into the cylinder head. Based on the information coming from this sensor, ECU control ignition timing as well as fuel injection timing because more fuel is required when the engine is cold and less if hot.

Crankshaft Sensor

It is a sensor that is used to measure the position of the crankshaft. It is generally placed on the engine block, the transmission housing, or the front pulley on which the timing belt is placed. Based on the information coming from this sensor, ECU control ignition timing as well as fuel injection timing.

Exhaust Temperature Sensor

It is a sensor that is used to measure the temperature of the exhaust gas before and after DPF. It is generally located on the exhaust manifold as well as the exhaust pipe. It finds out whether the temperature stays within the limits so that it does not affect the turbo, exhaust manifolds which can damage them if it is beyond those limits.

Fuel Pressure Sensor

It is a sensor that is used to measure the pressure of fuel in fuel lines. It is generally mounted on fuel pressure rail. Based on the information coming from this sensor, ECU can change the amount of fuel to be delivered in the engine.
Fuel temperature Sensor – It is a sensor that measures the temperature of the fuel. Based on the information from this senor, ECU can increase or decrease the amount of fuel required depending on the temperature. It is generally located inside the fuel tank or sometimes under the hood.

Intake Air Temperature Sensor

It measures the temperature of the air that flows through the intake to the engine cylinder. It is generally located on intake manifold pipes near the air filter box or sometimes it is part of the MAF sensor. Based on the information coming from the sensor, ECU changes the injection timing of the ignition system on the basis of the density of air entering the combustion chamber so that fuel is injected to get the best performance output from the engine.

Knock Sensors

It monitors the knock or detonations inside the combustion cylinder. It is generally located directly on the engine block with a screw. Based on the information from the sensor, ECU adjusts the ignition or fuel so as to overcome knocking which can cause damage to the pistons as well as the engine.

MAF Sensor

It is also known as Mass Air Flow Sensor. It calculates the density and the volume of the air taken in by the engine which in return helps in the proper amount of fuel are supplied to the engine. It is generally attached to the air filter box.

MAP Sensor

It is also known as Manifold Absolute Pressure Sensor. It measures the pressure inside the intake manifold. It is capable of sensing both under as well as overpressure inside. It is generally located on the manifold or on a vacuum hose from the intake manifold. Based on the information from the sensor, ECU calculate air density and determine the engine’s air mass flow rate, which in turn determines the required fuel delivery for perfect combustion

Lambda Sensors

It is also known as O2 Sensors. It generally measures the air-fuel ratio in the exhaust gases and compares it with the ambient air to find out whether the car is running on a rich, lean, or stoichiometric fuel ratio. It is generally located on the exhaust manifold near the catalytic converter.

TPS Sensor

It is also known as Throttle Position Sensor. It generally measures the position of the butterfly valve and communicates the data to the Engine control unit. This sensor screens how far down the accelerator pedal is pushed and tells us the position of the pedal. The situation of the pedal controls the amount of air going to the engine.