Engine Sensors for Cars

The Rise of Engine Sensors

New vehicles are increasingly equipped with more engine sensors, sometimes more than 100 sensors per vehicle in high-end cars – and that trend looks set to continue.
Valeo has been a global powertrain sensors specialist for more than 40 years. They bring that experience and expertise to the independent aftermarket with an Original Equipment (OE) quality range of engine sensors.

A Continuous Range Extension

Over 320 individual part numbers are currently available for the 9 types of engine sensors, including speed sensors, camshaft sensors, mass airflow meters, crankshaft sensors, oil pressure sensors, air intake temperature sensors, knock sensors, TMAP sensors and oil level sensors. Valeo continues to extend its engine sensor range and offers a one-stop-shop purchasing experience.

Added Value

Reasons to Choose Valeo Engine Sensors

• A premium range in which you can trust
• OE specifications - no compromise on performance and durability
• Perfect fit and easy installation
• Genuine technical support to help you service more efficiently

NOx sensors

What is a NOx sensor?
A NOx sensor is an electronic device that measures the concentration of nitrogen oxides (NO) in the exhaust gases of internal combustion engines, primarily diesel engines. It is used to monitor and optimize the performance of the exhaust aftertreatment system, such as the Selective Catalytic Reduction (SCR) catalyst.

Function of the NOx sensor ?
The combustion in vehicles produces Nitric oxide (NO), which converts into Nitrogen dioxide (NO₂) when it is mixed with oxygen (O) at high temperatures. NO₂ is a very pollutant gas for the environment.
To reduce the influence of NO₂ pollution the use of NOx sensors that work in combination with the (SCR) system are required.

How it operates?
The upstream NOx sensor continuously monitors the NOx content of the exhaust.
The Engine Control Unit (ECU) receives this signal and calculates the urea dose required to neutralize the NOx in the SCR catalyst.The urea injector sprays the calculated amount of urea into the hot exhaust gas.
 

The exhaust gases pass through the SCR catalyst, where the urea reacts chemically with NOx to convert it into nitrogen and water.The downstream NOx sensor verifies the efficiency of the SCR reaction by measuring the NOx concentration after the catalyst. The ECU adjusts the urea dosing in real-time to maintain emissions within regulatory limits.

NOTE: In some applications there is a possibility to just have one NOx sensor post the SCR catalyst.

Symptoms of a faulty NOx sensor?

• Check Engine Light (MIL) Activated
• Failed Emissions Test
• Reduced Engine Performance / Limp Mode
• Poor Fuel Efficiency
• SCR System Warnings
• Inconsistent NOx Sensor Readings

Speed Sensor

What is A Speed Sensor?

The speed sensor contains a pulse generator that converts the mechanical rotating movement into an electric signal to the speedometer through the Electrical Control Unit (ECU). This is mechanically driven from the gearbox in vehicles without ABS (before 2004). Inside the gearbox, the output shaft contains a gear wheel which rotates with the shaft. Linked to this gear wheel, and driven by it, is a small pinion gear, speedometer drive pinion.

Oxygen Sensor

What is An Oxygen Sensor?

Oxygen sensors, also known as Lambda sensors, are critically important for your vehicle. They work by comparing measurements of the remaining oxygen concentration in the exhaust gases and the oxygen content in the ambient air. They are the most effective way to monitor and regulate the combustion process. They control the air-fuel mixture ratio and ensure that the engine works at the optimum level.

Mass Airflow Meter

What Is a Mass Airflow Meter?

The Mass Airflow Meter measures the air density flowing into the vehicle’s air intake. The information provided helps the ECU deliver the proper mix of air-fuel mixture to the engine and the spark timing. The MAF measures the volume of air and compensates for its density.

Camshaft Sensor

What is A Camshaft Sensor?

The camshaft sensor monitors the engine speed and valve position and determines which cylinder is firing to synchronize the injector and the coil firing sequence. It sends signals to the Engine Control Module (ECM) to control the fuel injection, ignition timing and other functions. The camshaft sensor is essential for maintaining correct engine timing and proper engine function.

Crankshaft Sensor

What is A Crankshaft Sensor?

The crankshaft sensor detects the rotation speed and position of the crankshaft. This sensor sends information to the ECU to control the timing of fuel injection and the ignition system. It measures the RPM speed and is often mounted near the flywheel, which is a rotating TDC target (top dead centre.)

Oil Pressure Sensor

What is An Oil Pressure Sensor?

The oil pressure sensor measures the oil pressure in the sump and delivers the data to the ECU and the engine oil pressure gauge. In case of low engine oil pressure, the ECU will inform the driver and adopt control measures automatically to protect the engine.

Air Intake Temperature Sensor

What is An Air Intake Temperature Sensor?

The air-intake temperature sensor is mounted on the air intake manifold, detecting the mass airflow and sending a signal to the ECU. It detects boosts in air temperature by working in two stages with the mass airflow sensor, which also includes a temperature sensor.

Knock Sensor

What is A Knock Sensor?

The knock sensor detects the engine noises through different frequencies and sends a signal to the ECU. The ECU uses this information to limit the spark advance to prevent detonation from occurring. Every vehicle is equipped with a knock sensor for the control unit to the ignition system to anticipate a knock or detonation.

TMAP Sensor

What is A TMAP Sensor?

The temperature manifold air pressure sensor (TMAP sensor) detects the mass airflow and the pressure and sends this information as a signal to the ECU.

Oil Level Sensor

What is An Oil Level Sensor?

The oil level sensor ensures that the engine oil level does not become dangerously low without being noticed, which could cause damage to the engine. It can measure the oil level continuously, both in the dynamic and static range.