Throttle valve: signs and symptoms of malfunction, causes of problems with the sensor, solution to the problem

The throttle valve (DZ) is a mechanical regulator. It is located in the passage between the air valve and the manifold. It is needed to regulate air flows that must mix with fuel. It is an important element of the intake structure of the fuel system, leading directly to the engine.

Throttle valve: signs and symptoms of a malfunction, causes of problems with the sensor, solution to the problem - all this can be found in the article.

How to understand that the throttle valve is faulty

There are several signs of a bad throttle sensor:

When starting the engine, poor performance is observed;
The consumption of fuel resources increases;
The power is not stable, there are cases of its loss;
The running engine suddenly turns off. When you turn it on again, it works for a certain time, then stalls again;
At a speed of 120 km/h, traction may be lost;
The emergency light starts flashing, indicating an error;
The car is slow to accelerate and does not climb well;
You can hear popping noises and the smell of gasoline from the exhaust pipe;
Turnover becomes unstable;

If more symptoms of a malfunction of the throttle position sensor were noticed, this indicates that you need to find the cause and eliminate it. TPS signs of malfunction may also indicate other malfunctions of vehicle components.

Damper contaminated

The design of the throttle valve is directly connected to the ventilation system through which gases escape. This may lead to contamination. Dirt, dust, oil, and resinous formations most often settle on the walls. Subsequently, noise, knocking, and extraneous sounds may be observed. The operation of this equipment becomes poor. The electronic system indicates an error on the dashboard.

If you constantly clean this unit with special products designed for treating the carburetor system, then you can avoid TPS malfunction.

Throttle sensor problems

The remote control has a position sensor. This device is responsible for the reliability of data on the operation of this unit and its transmission to the ECU center. He, in turn, processes the symptoms of TPD. Thanks to it, there is an uninterrupted supply of air and its correct ratio with fuel resources, and there is an instant response to starting the engine.

If signs of a malfunction in the TPS become obvious due to false information or its complete absence, then the car’s electrical system processes the indicators and puts the entire system into standby mode. A signal appears on the corresponding light bulb. Signs of a malfunctioning throttle position sensor may indicate major problems with the transmission system.

System depressurization

If depressurization occurs in the intake tract system, then instability in engine operation occurs. Air leaks occur in the following parts of the car:

In sealed areas of the nozzle;
On exhaust systems for gasoline vapors;
On the walls of the throttle frame;
On idle jets;
On the vacuum brake booster pipes;
On the cleaning pipes.

Due to improper air removal, improper mixing of fuel masses occurs. Emergency symptoms are detected during the operation of the intake tract. The air leaving the system does not pass through the filtration system. It contains many harmful particles of dirt, metal, and plastic, which enter the engine and threaten to lead to poor performance of the latter.

Causes of malfunctions

Reasons why repair or replacement of the TPS may be required:

The contact elements have become acidic. This problem can hardly be called a breakdown, but it refers to malfunctions that can be eliminated. During prolonged use, the sensor contacts may oxidize. This is due to the operation of the TPS under conditions of temperature changes and exposure to moisture. To eliminate the problem, you need to dismantle the controller and clean the contact elements with cotton wool treated with WD-40.
Erasing the coating based on the initial segment of the slider movement. If the resistive base is removed, the controller will not operate correctly. As the slider moves, the voltage supplied to the control module will increase. But as a result of erasing, this does not happen, since there is no resistance. This leads to problems, and sometimes the control module malfunctions.
Damage to the tips on the device. If this happens, burrs will form on the lining, which will ultimately lead to failure of the remaining elements. In some cases, the contacts will continue to function, but this will not last long, especially since the wear on the substrate will increase. With such problems, the slider and the resistive layer will refuse to contact, which will lead to the inoperability of the machine’s motor.
Slider failure. This component of the device wears out over long-term use. As a result, it may deviate from the required trajectory, which will lead to problems.

One of the reasons for the failure of the throttle position controller is shown in the video of the “Everything Yourself” channel.

Damper adaptation problem

Adaptation may spontaneously reset. This will result in:

The battery will turn off and on.
Unstable operation in the electronic center of the car. It will freeze, show incorrect information, and indicate many errors.
The engine will turn off.

The reasons that lead to this may be the following actions performed previously:

When the battery pack was removed and installed back;
The electronic system was being re-flashed;
The throttle valve was removed for repair or cleaning;
The accelerator pedal was dismantled;
Poor condition of the power cord;
Excess moisture getting into the chip.

If the electronic system is worn out, shows incorrect data, or turns off, the problem may lie in the potentiometer. It is in the middle of the throttle. Its design contains graphite ribbons that require replacement.

Throttle Actuator

There are 2 types of these devices. The first is mechanical. It can be found on cars produced before 2000. The design of this device contains a steel cable, which over time can deform, stretch and even break. The cable connects these two nodes: the accelerator pedal and the handle on the rotation axis. The pressure exerted on it damages its structure and leads to loss of integrity.

The second type is electronic. It can be found on all modern cars. The position can be adjusted using the electrical control center. In accordance with the indicators about the state of the system, the last node, analyzing it, sends commands to the throttle unit. If data is received that reads signs of a malfunctioning throttle sensor, an alarm is generated. The electrical unit, in turn, registers this. Enables emergency mode. The warning light comes on.

What are the symptoms of a malfunctioning throttle position sensor:

The vehicle does not respond to the signal sent to the main engine unit by pressing the accelerator pedal.
The speed has decreased, the car picks up speed poorly.
The dynamics deteriorate, the car takes turns poorly.
During a cold start, insufficient speed may be observed, and the engine may turn off on its own.
Alarms are issued regarding errors in the system.

There are times when the electric throttle unit starts to malfunction. Then, having detected this problem, the car switches on the emergency lights.

Location and principle of operation of the meter

The sensor is installed on the throttle valve block and is mechanically connected to its axis. Thanks to this, the device is able to solve 3 problems:

inform the controller at what angle the throttle is currently open;
signal that the air supply is completely closed (the driver has released the accelerator pedal);
monitor the speed at which the damper opens.

Based on this information, the electronic powertrain control unit (ECU) makes a decision to increase or decrease the fuel supply and fuel injection for intense acceleration when the gas pedal is sharply pressed.

The operating algorithm of the resistive sensor is as follows:

At idle, the damper is closed and air flows into the engine through a separate channel. The voltage at the output of the device does not exceed 0.5 volts; the controller supplies fuel to maintain engine idle speed.
When the driver presses the gas pedal, the sensor slider moves along the resistive film. The resistance of the electrical circuit into which the device is connected in series decreases.
The ECU “sees” the increase in voltage in the meter circuit, makes a calculation, prepares the air-fuel mixture in the required quantity and supplies it to the cylinders. The maximum voltage at wide open throttle is about 4.5 V.
When the driver sharply presses the accelerator pedal, the controller notes a similar voltage surge and delivers a portion of the enriched mixture for dynamic acceleration.

Note. The operating voltage values are indicated for a common Russian car - VAZ 2110.

The non-contact throttle position sensor functions identically. The difference lies in the method of influencing the electrical circuit. A resistive device changes resistance using a slider moving across the film, while a non-contact device changes resistance due to the magnetic-resistive effect. Thanks to this principle of operation, the TPS lasts much longer and does not create problems for the owner of the car.

Features of throttle valve repair

When these signs and symptoms of a TPS malfunction are recorded, then repair work should be carried out. Their process depends on the problem. They may come as a set or require replacement of one unsuitable part. What is most often done:

If the throttle sensors are acting up or faulty, then they should be replaced. They are not subject to repair work.
It is imperative to clean the cold start regulator and the throttle valve from dirt.
Replacing gaskets, corrugated connecting tubes, restoring the tightness of the throttle valve.
Replacing an old, out-of-service device with a new one.

Debugg

During replacement, the potentiometer is de-energized and work is performed with the ignition off. To disconnect a faulty device, first remove the connector with cables, then unscrew the fastening screws.

Attention!

The seat is cleaned before removing the old potentiometer and before installing a new one. Dirt that gets on the contacts can damage the controller.

The installation of the new sensor is carried out slowly; its seat is connected to the end of the throttle axis and begins to be smoothly turned in a circle. When the mounting holes are aligned, screw in the screws and connect the connector. The controller remembers the error. To reset it, disconnect the negative terminal of the battery for a few minutes.

If after replacement the voltage does not correspond to the specified value (0.7 V/4 V), you will need to adjust the position of the TPS. To do this, the sensor is removed, rotated 90° relative to the damper rod, and reinstalled. Measurements are taken.

Operating a vehicle with a faulty TPS reduces the overall engine life. Timely diagnostics, replacement and adjustment of the sensor can be done independently. The cost of a new device depends on the car model and manufacturer; it can range from 400 to 5,000 rubles. Products from domestic companies are cheaper than imported analogues, but they have to be replaced more often.

Cleaning the throttle valve

This part of the car must be cleaned properly. Detailed instructions:

You should remove the throttle valve. To do this, you should first remove the air duct connecting the throttle to the air filter. This can be done with a special key.
The next step is to remove the damper itself. Depending on the design features of the motor, this manipulation is performed with some differences. But the main steps are as follows: remove the fastening bolts and disassemble the superimposed connectors.
Cleaning is carried out with special products that have excellent cleaning properties and remove even the slightest deposit of oily contaminants. Carburetor cleaner is in demand. It can be found at any automotive store. Its cost is affordable.
The product is sprayed onto the surface of the damper and the dirt is removed using a dry piece of cloth. No effort required. By lightly swiping with a cloth you can quickly clean the throttle from above and inside.
If there is a protection grille, then this should also be cleaned.
Install the remote control, connect all previously removed parts, and screw on the air duct.
Check the system operation.

Replacing the throttle position sensor and adjusting the new device

In most cases, replacing the sensor is quite simple and you can do it yourself. The whole procedure consists of three main parts: dismantling the old faulty device, installing a new TPS, resetting the error from the ECU memory. In some cases, you will need to adjust the new device.

Actions must be carried out with the ignition off and the sensor de-energized. Unscrew the two fastening screws and remove the connector from the device. Hurray, the old sensor has been removed.

To install a new sensor, you must carefully connect the end of the throttle axis to the device seat. The holes must be aligned while turning the device in a circle. Next, you need to screw in the mounting screws and secure the connector.

To correctly reset the error from the ECU controller, you must leave the terminals disconnected from the battery for at least 8 hours. Within approximately this period, the controller's memory should be reset to zero. The most reliable option, if the first method does not help, is to contact a service center, where the problem will be corrected using a motor tester. On the other hand, you can risk continuing to use the vehicle in a “gentle mode”, hoping that sooner or later the ECU will reset the error on its own.

Preventive measures

The DZ has a long service life and rarely breaks down. But mechanical damage to the housing itself may occur, or repair work must be carried out in the engine system. Then it or its components can be replaced. The sensor is always in the risk zone. It cannot be repaired and often needs to be replaced with a new one.

To prevent damage to this unit, it must be cleaned regularly. According to the manufacturer's recommendation, this should be done when changing the oil or after 20,000 km. mileage If these recommended preventive measures are taken, then the throttle valve and its sensor can serve the car owner for more than one year and subsequently will not need to be replaced.

Recommendations for choosing TPS

Quite often, car manufacturers install a cheap film-resistive throttle sensor. Such a mechanism will not work for a long time, and very soon symptoms of its malfunction will begin to appear.

Therefore, when replacing, it is recommended to use a non-contact sensor, which is more expensive, but is more reliable in operation and has a long service life. Its working principle is based on the magnetoresistive effect.

Sources

https://autoleek.ru/sistemy-dvigatelja/vpusknaya-sistema/drosselnaya-zaslonka.html
https://VazNeTaz.ru/drosselnaya-zaslonka
https://seite1.ru/zapchasti/drosselnaya-zaslonka-ustrojstvonaznacheniechistkaremont/.html
https://avtozam.com/elektronika/sensor/kak-proverit-dpdz/
https://tolkavto.ru/raznoe/drosselnaya-zaslonka-eto-chto-takoe.html
https://seite1.ru/zapchasti/datchik-drosselnoj-zaslonki-prednaznachenietipyvidyneispravnostifoto/.html
https://avtoskill.ru/remont-obsluzhivaniye/kak-proverit-datchik-polozheniya-drosselnoy-zaslonki-dpdz.html
https://AvtoNov.com/%D0%BF%D1%80%D0%B8%D0%B7%D0%BD%D0%B0%D0%BA%D0%B8-%D0%BD%D0%B5% D0%B8%D1%81%D0%BF%D1%80%D0%B0%D0%B2%D0%BD%D0%BE%D1%81%D1%82%D0%B8-%D0%B4%D0 %BF%D0%B4%D0%B7/
https://autofakty.com/proverka-datchika-polozheniya-drosselnoj-zaslonki-dpdz/
https://rad-star.ru/pressroom/articles/neispravnosti-datchika-drosselnoj-zaslonki/
https://okeydrive.ru/datchik-polozheniya-drosselnoj-zaslonki-kak-proverit-zamenit-otregulirovat/
https://motorsguide.ru/system/datchik-polozheniya-drosselnoj-zaslonki

Signs and causes of throttle valve malfunction