Engine oil pressure alarm. Malfunction of the oil pressure sensor

We examined in detail how the oil pressure sensor works and what causes malfunctions. Today, as promised, we will try to understand the verification methods, what methods and how effective they are. Here are diagnostic examples for two types of oil pressure sensors.

Ignoring a malfunction of the sensor or its measurements may lead to serious engine problems in the future. For example, rapid wear of the piston group (insufficient lubrication of rubbing parts), problems with the timing belt, ignition. The driver must understand that due to a faulty sensor, he does not know whether the required pressure oil or not. Both low and low temperatures have the same negative effect on the engine. high pressure, which can even lead to “” internal combustion engine.

How to diagnose the oil pressure sensor?

As we remember, there are two variants of DDM:

Electronic (the most common now).

Mechanical.

Therefore, due to certain technological differences, the diagnostic procedure itself will also differ. But first you need to accurately determine whether the problem is in the meter or something else. The first thing you need to do is check the oil level, there is a dipstick for this. We look at the volume, read the manual and decide what to do next. Everything is fine with the amount of liquid, following the method of elimination, we are trying to determine whether everything is normal with the lubrication system, that is, whether the pump is working or not, oil is passing through the filter, whether oil is supplied to the sensor itself, maybe the channels are clogged, anything can happen. To do this you need to do the following:

We turn off the power from the sensor, as a rule, there is a terminal there, there will be no problems.

Disconnected the terminal from the DDM sensor. Using the example of Lada Kalina 2006

We unscrew the sensor from its seat and be sure to plug it with a rag or something else so that the oil does not run out and nothing gets inside the internal combustion engine.

Unscrew the DDM sensor. Auto - Lada Kalina. Photo — drive2.ru

We turn it, and the crankshaft naturally turns along with it.

Now the most important thing is seat a pressure gauge is screwed in with a thread or simply with a piece of hose, only the connection must be as tight as possible. Check the pressure in three positions: at starter speed, at idle and during the normal operating cycle of the engine. Keep in mind that the readings may vary for almost all cars, so read the manual. If the readings are close to factory values, we look for problems in the sensor or electrical circuit.

Now, as for directly checking the sensor. First, let's check the electrical DDM. So:

We remove the sensor.

We connect a pump with a pressure gauge to it, try to achieve a tight connection. You can do without a pressure gauge, but then there is a risk of applying too much pressure to the sensor, which will definitely cause it to fail and the membrane to deform.

Now we connect a multimeter to the sensor, set the resistance measurement mode, and check for an open circuit. Without pressure, the sensor should show zero resistance.

Pump at about 1.5 Bar, no more. At the same time, before doing this, check at what values ​​​​the pressure gauge needle “hangs”; you need 0 Bar.

Now look, when you apply pressure to the sensor, if the latter is working properly, the multimeter should show infinity, that is, an open circuit. Under pressure, the membrane bends, pushes the rod and the latter breaks the chain.

There is another option, easier for most drivers. Disconnect the wire from the sensor and short it to ground. In this case, if the sensor is working properly, the light on the instrument panel will not light up. Then the problem is either in the wiring or in the light bulb itself, maybe it just burned out, which happens quite often. If the light comes on, then there is definitely a problem with the oil pressure sensor.

Examination

If everything is in order with the DDM, check, as already mentioned, the wiring, terminals or the light bulb itself, maybe it’s burned out.

Now, as for mechanical sensors, a largely similar procedure can be performed with them. To check, you will need a pump with a pressure gauge and you will have to remove the sensor. We connect the pump to the sensor, keep in mind that there must be a tight connection. We begin to supply air to the sensor at different pressures, while recording the readings from the pressure gauge and from the ohmmeter (resistance). If no action is taken on the dial indicator (ohmmeter), there is most likely a problem with it. Next, the recorded readings from the pressure gauge and ohmmeter should be compared with the values ​​​​from the car manufacturer. As a rule, in technical documentation Data on so-called ideal measurements are provided. Compare them, if they differ significantly, the problem is with the sensor.

Conclusion

As you can see, the procedure for checking oil pressure sensors is slightly different, depending on their type. Of course, take this fact into account when diagnosing your car.

You should not neglect the readings from the car’s “tidy”, otherwise you may end up in serious repairs, since the cause will not be diagnosed in time. If the problems do not turn out to be with the sensor, which worked correctly and warned you, then the malfunctions can lead to wear of the piston group or even fire of the car if there are problems with the wiring.

In a modern engine, oil pressure readings are necessary both for the purpose of monitoring and optimizing the operation of the internal combustion engine. The oil pressure sensor is a device that converts mechanical force into an electrical signal. After it is decoded by the vehicle's control unit, the driver receives information about the pressure in the lubrication system, displayed on the dashboard in real time.

Purpose

Experienced motorists know that oil is supplied to places where there is friction of internal engine elements. different ways, one of which is splashing. This function requires a lot of pressure to be applied.

When it decreases, which is possible when the oil pump fails or the amount of oil in the system decreases, the friction of the components increases, resulting in jamming or accelerated wear of parts. To avoid such consequences and prevent them in a timely manner, a special element- pressure meter.

If you are interested in where the oil pressure sensor is located on your car, you should open a book on the repair and operation of the car that you own. As a rule, the oil pressure sensor on domestic cars, in particular LADA cars, should be looked for behind the cylinder head, not far from the timing belt casing.

Modern type oil pressure sensor

Having found out where the sensor is located, which is responsible for promptly notifying the driver about a drop in oil level, you should understand its structure. Modern models are a converter mounted in the cylinder block. Its readings are transmitted to an electronic scale or to an on-board computer in the form of a special electronic signal. To perform this task, a so-called intermediate converter is built into the sensor housing, which converts the force mechanical type into an electrical signal.

The role of the sensitive element in such devices is performed by a rigid metal membrane. It, in turn, is equipped with a resistor, which is distinguished by its ability to change resistance in response to deformation. The resistance is then converted into an electrical signal using a special measuring circuit, transmitted via the CAN bus or wires.

Reasons for a drop in oil pressure in the system

An engine malfunction is always indicated by too high or very low oil pressure. In the best case, it may turn out that the engine is working properly, and the oil pump is to blame, but you need to be prepared for even the most unpleasant consequences.

If the pressure is too high, it may be due to:

• blockage in the lubrication system;
• blockage of oil channels located in the walls of the cylinder block;
• clogged pressure reducing valve with wear products.

In case of very low pressure in the system, this could be caused by:

• weakening of the oil pump spring;
• wear and tear of its entire structure.

Having learned the location of the oil pressure sensor, it design features and structure, the most important thing remains - to make a correct diagnosis of why the pressure in the lubrication system has ceased to meet the norm. There are many reasons for incorrect oil pressure, and not all of them indicate serious damage.

System pressure when starting the engine winter period time may be normal. But it is worth warming up the engine until operating temperature, oil pressure can drop to almost zero. This can easily be explained by the drop in oil density that occurs when it warms up.

Video

See how the oil pressure sensor is removed on a VAZ 2112:

In device vehicle The engine plays the most important role. Romantic drivers call it “the heart of the car.” But power unit there is one weak point - the lubrication system for rubbing parts. The only control element of this system is the oil pressure sensor (OPS), which can present the driver with many surprises.

Why do you need an oil pressure sensor?

DDM is the most important component of the lubrication system of an engine unit. The device is responsible for monitoring the oil pressure that is supplied to the engine and, in case of any failures, transmits a signal to the driver’s cabin - the corresponding light comes on.

To understand the importance of the sensor in the design of a car, you will need to know how exactly the oil is supplied to the rubbing parts in the engine. Depending on the type of machine and its year of manufacture, lubricant can be supplied in various ways, including simple spraying. However, even this method involves creating required pressure so that the unit is supplied optimal quantity oils If the amount of lubricant is stable, the rubbing parts of the engine will ensure good, uninterrupted operation without rapid wear.

For timely warning of various negative factors in the lubrication system and a DDM is installed, which is sensitive to all changes in oil supply.

The driver is given a signal by sound and visual methods: a sharp squeak is heard in the cabin and a red indicator in the form of an oil can appears on the instrument panel. In some types of cars, oil pressure characteristics are displayed in a separate dial gauge, which shows Current state lubrication systems.

Did you know that the level of seat pressure can be influenced by the height of the vehicle's location relative to sea level?

Types of DDM and the principle of their operation in modern cars

The modern automotive industry uses two types of such sensors. Each type works with certain types of engines and talking about which sensor is better/worse is not acceptable.

Mechanical sensor

The device most accurately determines the oil pressure in the system and transmits the readings to a scale in dashboard.

The mechanical device has a complex design: a housing cup, a membrane, a pusher, a slider and a winding nichrome wire. Due to the use of many components mechanical sensors have a high cost.

The operation of such a device is as follows: the slider, which is located on a platform with a nichrome winding, receives the force of oil pressure, rises or lowers. His every movement is transmitted to a dial indicator in the car’s interior, so the driver will always be accurately informed about the pressure of the lubricant in the engine. The slider receives data from the effect of oil on the sensor membrane.

Electronic sensor

This type of sensor is simpler, but it cannot transmit all changes in the lubrication system to the driver. As a rule, the electronic type of device shows only two main values: normal pressure and critical.

Thus, its only purpose is to convey to the driver the information that the system pressure is zero. To do this, its design uses only a housing cup, a membrane, a pusher and a contact system with an oil pressure light in the car's interior.

Accordingly, if the pressure disappears, the membrane straightens, since nothing presses on it. The pusher immediately slides into the housing, the contacts close - an alarm signal is sent to the cabin.

On some vehicle models, two types of sensors are installed at once. This expands the driver’s ability to constantly monitor the engine lubrication system. If one device fails, you can rely on the readings of the second.

Location of the device in different types of cars

Depending on the make and model of the car, the location of the sensor may vary. Each automaker has its own approach to combining engine compartment mechanisms.

Most often, the DDM is located in close proximity to the cylinder head and oil filter. In some cases, to get to the device, you just need to open the hood and get to the sensor without dismantling other elements. In other situations, the sensor can only be removed from below, through the wheelbase.

Normal location - near the engine

Table: where are the oil pressure sensors located on popular car models

Causes and symptoms of malfunction

The driver of any vehicle should know that most often, malfunctions in the lubrication system do not present any particular difficulties in eliminating them. However, breakdowns may also occur that require the intervention of a service station specialist and specialized equipment.

Signs of a malfunction in the oil pressure sensor may include:

loss of power by the car during acceleration;

instability of the ignition switch;

sharp jolts when driving at low speeds;

inability to start the car.

The reasons why the DDM fails include:

exhausted life of the device;

membrane deformation;

short circuit in the wiring;

sensor relay failure.

Therefore, it is necessary to pay the utmost attention to such a device as the DDM, since the condition of the engine depends on its performance. If the sensor begins to “lie” and “get confused in the readings,” the rubbing parts of the power unit will wear out very quickly, which will ultimately lead to engine seizure.

How to connect an external

In some cases, vigilant and experienced car enthusiasts connect a remote oil pressure sensor to their car. This is the measure that will ensure reliable control above the engine lubrication system. On the one hand, the functions of the sensor will be provided as usual, and on the other hand, it will be possible to look at the pressure force in the system at any time.

The procedure for connecting the remote device:

Open the hood.

Install the tee (adapter) in place of the oil pressure sensor.

The sensor itself and the signaling device are connected to the adapter connectors.

The wire from the device is pulled into the cabin.

The color of the wires determines the connection to the instrument panel.

Thus, without much difficulty you can install and connect additional device for oil pressure control.

Thanks to a clear graduation scale, the driver will always know the exact pressure in the system

How to replace

Replacing the DDM in the event of its breakdown is a necessary operation. Without this device, further operation of the vehicle is impossible or unsafe.. In addition, almost any driver can change the sensor themselves.

You will need to securely tighten the new sensor, and then check the connection for leaks

Video: replacing DDM with your own hands

Thus, even as an inexperienced driver, you can both check and replace the oil pressure sensor on any car. The main thing is not to be afraid of difficulties and act carefully so as not to damage the devices, hoses and wires adjacent to the sensor.

The operation of a modern engine is impossible without additional sensors. The times when the motor was not dependent on electronics are far gone. Now all processes are controlled by an electronic control unit. But it does not act on its own. Each signal is adjusted depending on the readings of a particular sensor. In today's article we will look at one of the most important elements in this category. This is the oil pressure sensor. What is it, how does it work and where is it located on different cars? You will find out the answers to these questions below.

Purpose

During engine operation, lubricant must flow into all its components, including the crank mechanism. The oil is supplied by spraying. To form a good and dense lubricating film, the liquid must be supplied under high pressure. It can reach five atmospheres or higher. If the pressure level becomes lower than normal, the friction of the elements of the crank mechanism increases significantly. Nodes and assemblies lose their resource, production appears. To prevent this, the design of any engine has an emergency oil pressure sensor. It is he who warns the driver about the problem and allows him to stop the movement and operation of the internal combustion engine in time.

Where is the oil pressure sensor located?

This element can be located in different places. Each manufacturer places the oil pressure sensor in the engine differently. But often this part is located in the area of ​​the cylinder head. In some vehicles it can only be accessed from below (through the wheelbase).

On a Lada-Kalina car, the oil pressure sensor is located in the cylinder head socket, near the timing belt casing. Only one wire comes from this element. As for the Daewoo Lanos, the element is located at the bottom of the engine, near the oil pump. A bundle of insulated wires comes from it. Things are a little different with German cars. For example, in the Volkswagen Golf and Jetta, the first emergency oil pressure sensor is located on the bracket before the filter. And the second element is located at the outlet of the oil purifier. In Opel Astra cars, this part is located on the generator side, on the right side of the engine. There is only one sensor here, and only one wire comes from it.

But it is accessed through the right front wheel. Otherwise it is difficult to reach him. On GAZ vehicles with ZMZ engines, this element is located on the cylinder head on the right side. There is also only one wire connected to the sensor.

How is it arranged?

The design of this element is quite simple. An automobile oil pressure sensor consists of:

• Membranes.
• Movable contact.
• Cases.
• Pusher (moving contact rod).
• Membranes.

This element must be in contact with the warning lamp on the instrument panel. Let's look at how the VAZ oil pressure sensor works below.

Principle of operation

After turning on the ignition, +12 V power is supplied to one of the signal lamp contacts. The second contact of the sensor is connected to a movable rod. The operating algorithm of the element is based on the closing and opening of the second terminal of the lamp. A separate pusher is responsible for this. It shorts the lamp to ground and connects to the sensor diaphragm. Its upper part is in contact with oil system.

As the lubricant pressure increases, the force on the diaphragm element of the sensor also increases. As a result, the diaphragm bends. At the same time, the contacts are moved away. If there is no pressure in the system or below normal (usually a level of less than 0.2 Bar), the diaphragm will not bend and will remain in its original position, in which both contacts are closed. As a result, power will go to the lamp, and the corresponding icon in the shape of an oil can will light up on the dashboard.

Thus, the principle of operation of the sensor is to close the contacts, as a result of which a signal will be sent to the instrument panel. Depending on the type of vehicle, this light will flash or stay on (usually red). Sometimes a buzzer indicates insufficient oil pressure. The driver hears an obsessive squeak. The engine sends out a kind of distress signal.

What to do if the oil pressure sensor is on?

This situation occurs extremely rarely. But if the lamp comes on, you need to immediately look for a place to stop and urgently turn off the engine. It cannot work without oil pressure (even if its level on the dipstick is maximum). This will cause increased wear of friction pairs.

The motor will suffer from oil starvation. What needs to be done next? After parking, you need to go to the repair site - by tug or tow truck. But in no case should you engage the gear while driving - the piston gear will operate without oil supply at this time.

Signs of sensor malfunction

Unfortunately, characteristic features There is no malfunction of this element. You will not feel increased fuel consumption, a drop in power, acceleration dynamics or other changes in the way you drive your car. The only way to recognize a non-functioning element is to check whether the lamp lights up when the ignition is turned on. Just like the “Check” and other warning lights, it should light up when the key is turned to the third position. If the sensor icon disappears, there is most likely an open circuit. Or the lamp itself on the instrument panel burned out, which is unlikely, but theoretically possible.

Please note: after starting the engine, the sensor may remain on for some time on the instrument panel. Usually this is 3-5 seconds, during which the pump still operates at low pressure. Also, a similar lamp lights up after an oil change (the pressure sensor has nothing to do with it). Part of it should be filled into the filter and other elements of the internal combustion engine. Do not panic if the control device lights up for a short time. However, if this period is more than five seconds, it is worth thinking about the health of the power unit. The oil pump may need repair.

Reasons for failure

What cases lead to replacing the oil pressure sensor? This can happen in several cases:

• When the sensitive membrane is deformed.
• Due to a broken contact or short circuit in the wiring.
• If the sensor relay fails. But it is worth noting that not all cars have such an element.
• When the device resource is exhausted.

Since the design of the sensor is very primitive, there is practically nothing to break here. Therefore, in most cases, the part does not work precisely because of a broken contact or damage to the membrane.

Conclusion

So, we found out what the oil pressure sensor is, how it works and how it works. Despite its size, this small part plays a vital role in the operation of the engine. In critical situations, the sensor sends an alarm to the panel. This allows you to stop the engine in time and prevent it from starving of oil.

An oil pressure sensor is a device that converts mechanical force into an electrical signal of different voltages, which, after decoding, allows you to judge the pressure in the lubrication system in real time.

Why do you need an engine oil pressure monitoring sensor?

Oil is supplied to friction points in the engine different ways– including splashing (for which purpose), for which it is necessary to create pressure.

In order to save money when tuning an engine in a car that does not have a standard device for monitoring oil pressure, you can purchase and install a budget device from a Russian truck

If it decreases, which may occur due to a decrease in the amount of oil in the system or failure, the friction of the components increases, which leads to accelerated wear or jamming of parts. To prevent these consequences in a timely manner, a pressure sensor is built into the lubrication system.

Reading a signal can be implemented in different ways. Most often, the driver does not see detailed readings and can only be guided by the activation of the alarm with a pictogram depicting an oil can on the instrument panel if the pressure drops to a critical level. In some cars, the engine oil pressure is displayed on a separate scale. In the most modern cars, pressure sensor readings are used not only to monitor the condition of the engine, but also to optimize its operation.

Oil pressure sensor device

The operation of most pressure sensors is based on the principle of converting one type of energy into another. Primary transducers produce a mechanical force, which either exerts direct impact to the sensing element measuring instrument(pointer pressure gauges), or converted into an electrical signal. In modern cars, pressure sensors of the second type are used, since the electrical signal can.

Old-style sensor device

A classic dial gauge on the dashboard of old cars (for example) in combination with a sensor is a type of pressure gauge. In old-style instruments, oil pressure measurement was based on the deformation of an elastic sensing element (membrane). Deforming, the membrane pressed on the rod, compressing the liquid in a sealed tube. At the other end, the liquid pressed against another rod, which raised a mechanical needle. Such an automobile device is called a differential pressure gauge.

Depending on the country of manufacture, the oil pressure reading scale can be graduated in Pascals, Newtons per square meter, bars, atmospheres or kilogram-force per square centimeter

Modern oil pressure sensor

In more modern models measurement is carried out by a transducer sensor mounted in the cylinder block, and the readings are transmitted in the form of an electronic signal to or on an electronic scale. For this purpose, an intermediate converter is provided in the sensor housing, which converts the mechanical force into an electrical signal.

In such devices, the role of a sensitive element is performed by a rigid metal membrane equipped with a resistor that changes resistance in response to deformation. The resistance is converted by the measuring circuit into an electrical signal, which is transmitted through wires or via the CAN bus.

Oil Pressure Sensor Operation

In a serviceable engine that has warmed up to operating temperature, the oil pressure at idle should be around 2 bar. Oil pressure at high speeds (as a rule, for most engines this is .) from 4.5 to 6.5 bar. If the pressure fluctuates within acceptable limits, the contacts in the electrical converter circuit are open and the oil on the dashboard does not burn.

On average level oil pressure is affected by the height of the vehicle above sea level

Overall, the oil pressure sensor is reliable and rarely fails. Most often, troubles happen with the seal, which prevents oil from leaking out of the cylinder block. It is necessary to monitor its condition, since in the event of an oil leak, it ends up on a hot block, which can lead to a fire.

Reasons for the drop in oil pressure in the system

Too low or too high pressure always indicates a problem with the engine or at least the oil pump.

If the pressure is high, there may be a blockage somewhere in the system. Perhaps the oil channels in the walls are clogged, or perhaps clogged with wear products.

If the pressure is too low, it may be a weakening spring or general wear of the oil pump.

Situations where incorrect pressure occurs can be different, and they are not necessarily associated with breakdowns. For example, when starting the engine, the pressure in the system in which it circulates may be normal, but after warming up to operating temperature, drop to almost zero. This is due to a drop in oil density when heated.