Sensors

Crankshaft sensor

The crankshaft position sensor, or BDP sensor, is mounted on the gear ring of the flywheel, which is mounted directly on the crankshaft. This sensor counts the number of teeth and at what speed they pass the crankshaft position sensor. One tooth is omitted on the gear ring so that the crankshaft position sensor knows the position of the crankshaft. Then these signals are transmitted to the engine control unit (ECU) and the engine speed and ignition timing are determined. Because of the position of the crankshaft, the ECU knows where the upper dead point is and can time the ignition.

In case of a faulty crankshaft position sensor, the engine will no longer start because there is no input from the sensor. Another feature is that the tachometer remains at 0.

MAP sensor

The Manifold Air Pressure (MAP) sensor is a pressure sensor which is mounted in the intake manifold of some cars. This pressure sensor measures the overpressure or negative pressure in the intake manifold and sends this signal to the ECU. In this way, the MAP sensor measures the engine load, as the overpressure or negative pressure in the intake manifold is a measure of the filling ratio. Based on the signals from the intake manifold pressure (MAP) sensor, the ECU calculates the fuel injection.

Tyre pressure sensor

The tyre pressure sensor, or TPMS (Tyre Pressure Monitoring System), monitors tyre pressure for safety reasons. If the tyre pressure drops significantly, this will be communicated to the driver to warn him or her of a flat tyre in a timely manner. The tyre pressure sensor will generate a message at about half a bar deviation. If this is set to be too sensitive, a message may appear when the tyre temperature changes because the pressure drops or rises with temperature changes. This is far from ideal as it means that messages will appear continuously. When fitting new tyre pressure sensors, they must be re-learned and recalibrated in order to prevent malfunctions.

Knock sensor

Knock sensors (also called pinging sensors or detonation sensors) are mounted on the engine block to promptly detect when the engine is about to detonate. This detonation or knocking happens when the fuel mixture (petrol or gas) is not ignited by the spark plug but by the heat of the engine, which is also called self-ignition. This can cause serious engine damage, such as holes in pistons. When an engine starts to detonate, certain vibrations occur in the engine block which the knock sensor can detect. If the knock sensor detects these vibrations, the ignition timing can be adjusted back to prevent engine damage. The larger the engine block, the more knock sensors that are mounted, usually one knock sensor per two cylinders.

Air pressure altitude controller sensor

The air pressure sensor for the altitude controller is applied to cars with air suspension. Here you will find the correct air pressure sensor for your vehicle.

Reservoir level sensor

Here you will find the correct level sensor for your vehicle's windscreen washer system.

Camshaft sensor

The camshaft sensor provides the signal to the ECU (engine control unit) to determine the position of the camshaft(s) in relation to the crankshaft. This information is used to determine injection timing and ignition timing. Like the crankshaft position sensor, it is a type of Hall sensor which scans the gear ring (camshaft sprocket). Because one tooth is missing on the gear, the ECU can calculate the exact position.

A defective camshaft sensor can cause the engine to start with difficulty or not start at all and may also result in an engine malfunction indicator light.

Oil pressure sender unit

The oil pressure sender unit, as the name suggests, measures the oil pressure at certain places in the engine block. This is essential because low oil pressure can cause major engine damage and the driver should be informed of this by means of an indicator light in the dashboard. If the oil pressure sender unit is defective, this warning mechanism is no longer operational and it is impossible to know if the oil pressure has dropped.

Brake pedal position sensor

The brake pedal position sensor transmits the position of the brake pedal to the engine control unit (ECU) and the ABS module. Here you will find the correct brake pedal position sensor for your vehicle.

Water temperature sensor

The water temperature sensor often has a dual function. This sensor measures the temperature of the cooling system and transmits it to the temperature gauge on the dashboard and to the ECU. The ECU uses this signal to control the injection and ignition of the engine. Whereas, in the past, a manual choke was used, this system takes over automatically. If this water temperature sensor is defective, the ECU cannot process the information and the engine will run poorly. It is also possible that the coolant temperature can no longer be read in the dashboard.

Suspension sensor

Here you will find the right sensor for the suspension of your vehicle. This could be a sensor for the transverse acceleration or a sensor mounted on the support arm for an active undercarriage.

Eccentric shaft sensor

The eccentric shaft sensor is mounted on the cylinder head and controls the variable valve lift used in some car, e.g. BMW's Valvetronic. This sensor measures the position of the eccentric shaft and sends the information to the engine control unit (ECU). With modern systems, a faulty sensor actually always results in an engine malfunction indicator light.

Accelerator pedal position sensor

The accelerator pedal position sensor is a potentiometer and sends the position of the accelerator pedal to the engine control unit (ECU). In this way the ECU knows exactly how much power is required by the driver and adjusts injection, ignition timing and throttle valve position, among other functions. If the accelerator pedal position sensor fails, the engine may no longer respond at all to accelerator pedal movements, go into emergency running mode, and illuminate the engine malfunction indicator light.

Coolant level sensor

The coolant level sensor is usually installed in the coolant reservoir. This sensor ensures the levels of coolant in the system do not get too low and, if they do, warns the driver in a timely manner and prevents overheating. Here you will find the correct sensor for your vehicle's coolant level.

Oil level sensor

The engine oil sensor registers the amount of oil in the engine block. Usually this sensor is mounted in the sump pan of modern vehicles to be able to digitally read the engine oil level. This replaces the regular oil dipstick. If the sensor is faulty, it will not be able to gauge the oil level and, in many cases, an engine malfunction indicator light will illuminate.

Oil temperature sensor

The oil temperature sensor records the temperature of the engine oil and transmits this to the ECU. In some cases, one sensor combines the oil level sensor and the oil temperature sensor. If the oil temperature sensor malfunctions, the oil temperature gauge will not function and the engine malfunction indicator light will illuminate.

Parking sensor

Here you can find the right parking sensors for your vehicle. If these sensors do not function properly, a Parking Assistant (PDC) failure will most likely occur. It is also possible that the PDC does not work at all or is hypersensitive due to a faulty sensor.

Throttle valve sensor

Here you will find the right throttle valve sensor for your vehicle, also called the throttle valve position sensor for petrol engines. In diesel engines this is called the throttle valve. A defective sensor will illuminate an engine malfunction indicator light and may cause the engine to run in emergency running mode and give off reduced power.

Exhaust gas temperature sensor

The exhaust gas temperature sensor, also called the EGT sensor, is mounted in the exhaust to check certain elements on the basis of the temperature. These include checking the operation of the diesel particulate filter and the EGR valve. A malfunctioning exhaust gas temperature sensor will cause the engine malfunction indicator light to illuminate.

Wilmink Engine Parts also supplies various other sensors:

ABS Sensor
Outside temperature sensor
Fuel tank pressure sensor
Air temperature sensor
Speed sensor
Steering angle sensor
Exhaust gas pressure sensor
Filling pressure sensor
Fuel water sensor