Where is the Toyota Overlord s knock sensor?

Detect engine knocking to suppress the occurrence of knocking phenomena. When the engineer adjusts the knock sensor, the vibration pattern of the knock is written into the electronic control unit. If the knock sensor detects a vibration pattern, the ECU determines the engine knock and then delays the ignition advance angle.

Currently, advanced knock sensors can even tell which cylinder is knocking and delay the ignition advance angle of that cylinder separately. 

The knock sensor is mounted in the middle of the engine block. For example, a four-cylinder engine is installed between cylinders 2 and 3, or one between cylinders 1 and 2 and one between cylinders 3 and 4. It is used to measure engine shake and adjust the ignition advance angle in case of engine knocking.

Usually piezoelectric ceramics. When the engine vibrates, the ceramic inside is squeezed to produce an electrical signal. Because this electrical signal is very weak, the connecting wires of ordinary knock sensors are wrapped with shielded wires.

Knock sensors are AC signal generators, but they are very different from most other AC signal generators in cars. In addition to detecting the speed and position of rotating shafts like magnetoelectric crankshaft and camshaft position sensors, they also detect vibration or mechanical pressure. Unlike stators and magnetoresistors, they are typically piezoelectric devices.

They are made of special materials that can sense mechanical pressure or vibration (for example, when the engine starts knocking, it can generate alternating voltage).

Engine damage can occur due to premature ignition, poor exhaust gas recirculation, and engine knocking caused by low-quality fuel. The knock sensor provides a knock signal to the computer, prompting the computer to readjust the ignition timing to prevent further knocking. They actually act as "oxygen sensors" in the ignition timing feedback control loop.

The working principle of the knock sensor: when the engine vibrates or knocks the cylinder, the piezoelectric ceramic produces a voltage peak, and the greater the knock or vibration, the greater the peak. The engine control unit (ECU) processes the signals received by the detonation sensor, and if a detonation is determined, the ignition is postponed and the detonation continues.

When the engine control unit ECU does not receive the signal from the knock sensor, the ignition time is advanced to ensure the optimal output of the engine. Therefore, the purpose of using a knock sensor is to improve the dynamic performance of the engine without knocking.

Mounted in the cylinder block, somewhere.

In the middle of the engine block side.

Hello, generally the knock sensor is on the cylinder block, either in front or in the back.

What is engine super knocking.

Engine "super knocking", also known as low-speed premature ignition, is an abnormal combustion phenomenon unique to supercharged direct-injection gasoline engines. When the engine inhales the mixture of fuel vapor and air, in the process of compression, due to the mixture of low ignition point substances in the fuel, it will cause the gas mixture to automatically deflagrate before the ignition of the spark plug, forming a new ignition point, and the flame spreads outward at a speed several times higher than the normal combustion, so that the cylinder wall is affected and vibrates, which is called detonation. To put it simply, knocking is a manifestation of abnormal pressure in the combustion chamber caused by abnormal combustion.

A phenomenon when detonation occurs.

The engine will emit a crisp and discontinuous metal knocking sound when a slight knock occurs, while a continuous metal knocking sound will occur when the engine will have a continuous metal knocking sound during a severe and continuous knock, and the engine power will also be significantly reduced.

What are the causes of detonation?

1 The air-fuel ratio is incorrect, and the mixture is too dilute to increase the combustion temperature, thereby increasing the engine temperature.

2. The octane number of fuel is too low, the octane number is an indicator of anti-detonation, the higher the octane number, the stronger the anti-detonation, and the lower the conversely, it is easy to detonation.

3. The cleanliness of the fuel is insufficient, and some physical substances and chemical impurities contained in the fuel, including some aromatic substances, will cause spontaneous combustion and detonation during the compression process of the engine.

4. Excessive carbon deposition in the combustion chamber, due to the serious carbon deposition, the actual volume of the cylinder becomes smaller, the compression ratio increases, and at the same time, the carbon deposition in the high-temperature environment will always burn red due to the poor heat dissipation ability, so that the high-temperature compressed mixture is not only ignited by the sequential spark plug, but also randomly ignited by the high-temperature carbon deposition in the cylinder, resulting in detonation.

5. The engine temperature is too high, the engine is too hot in the environment, the inlet air temperature is too high, or the engine cooling water circulation is poor, which will cause the engine to detonate at high temperature.

6 The ignition angle is too early, so that the piston can gain power as soon as it enters the power stroke after the compression stroke is completed, it is usually ignited before the piston reaches the top dead center. Ignition too early will cause most of the oil and gas to burn when the piston is still compressing the stroke, and the unburned oil and gas will be subjected to great pressure and spontaneous combustion, resulting in detonation.

The methods to solve detonation are as follows.

1. Use fuel that conforms to the compression ratio of the engine.

2. Avoid "drag gear" driving.

3. Regularly clean the carbon deposits and fuel injectors in the oil circuit.

4. Avoid high temperatures: check the coolant water level regularly, check and change the engine oil regularly, avoid long-term intense driving, and monitor the water temperature frequently when driving in summer.

5. Appropriate selection of high-quality fuel additives. For example, fuel additives containing PNF stock solution can solve the problem of engine knocking to a certain extent.

Toyota's knock sensors are right on the cylinder block, and if memory serves, there should be two.

Engine block.

1. General central location.

It is used to detect whether the engine is detonating.

to condition the ignition timing.

Generally behind the engine, on the cylinder block, next to the oil filter cartridge seat. There is a plug with a wire on it, which is located on the front oil duct of the oil filter.

The electronic oil pressure sensor consists of a thick film pressure sensor chip, a signal processing circuit, a housing, a fixed circuit board device, and two leads. The signal processing circuit is composed of a power supply circuit, a sensor compensation circuit, a zeroing circuit, a voltage amplification circuit, a current amplification circuit, a filter circuit and an alarm circuit.

Figure 1 is a structural diagram of the sensor, and Figure 2 is a block diagram of the sensor. The thick film pressure sensor is a new type of strain pressure sensor that appeared in the 80s of the 20th century, which is developed by using the piezoresistive effect of the thick film resistance printed and sintered on the ceramic elastomer. Four thick film resistors are directly printed and sintered on a ceramic elastic diaphragm and connected to form a Wheatstone bridge through a conduction belt.

When the measured liquid level pressure acts on the ceramic elastomer, the elastic diaphragm produces deflection deformation, and at the same time, the thick film resistance imprinted on the elastic diaphragm also produces strain of the same magnitude, and the resistance value of two thick film resistors decreases under compressive strain. The other 2 tensile strains increase the resistance value. In this way, the measured pressure value is converted into a bridge output signal, and the signal size is proportional to the pressure.

Behind the intake manifold, the intake manifold needs to be disassembled.

The speed sensor is located on the right rear side of the engine gearbox and is usually fixed with an M8 screw.

The vehicle speed sensor detects the speed of the electronically controlled car, and the control computer uses this input signal to control engine idling, torque locking of the automatic transmission, shifting of the automatic transmission, opening and closing of the engine cooling fan, cruise control and other functions. The output signal of the vehicle speed sensor can be a magnetoelectric AC signal, or a Hall digital signal or a photoelectric digital signal, the vehicle speed sensor is usually installed in the drive axle housing or transmission housing, and the vehicle speed sensor signal line is usually installed in the shielded jacket, which is to eliminate the electromagnetic and radio frequency interference generated by the high-voltage electric fire wire and the vehicle-mounted ** or other electronic equipment, which is used to ensure that electronic communication is not interrupted and prevent the deterioration of driving performance or other problems. Magnetoelectric and photoelectric sensors are the two most widely used vehicle speed sensors in automobiles, and magnetoelectric sensors are widely used in various automobiles in Europe, North America and Asia to control vehicle speed (VSS), crankshaft angle (CKP) and camshaft angle (CMP), and can also be used to feel the speed and position signals of other rotating parts, such as compressor clutches.

Speed? The speed of the vehicle is calculated by the ECU through the wheel speed sensor (the rotational speed of the wheels).

1) Check whether the engine is obviously overheating, and if so, find out the cause first. (There are many related causes of engine overheating, pay attention to analysis).

2) Check if the engine knocks due to the failure of the ignition system.

If the ignition advance angle is too large, the mixture will burn too fast, resulting in engine knock combustion. The reasons for the ignition advance angle are as follows: the crankshaft position sensor is installed in the wrong position (or loose), the timing belt is installed in the wrong tooth, the operation program of the power control module is faulty, the air intake detected by the flow sensor in the air is too small, and the detonation sensor is slow to respond.

3) Check if the pressure in the fuel system is too low.

If the pressure of the fuel system is too low, causing the mixture to be too thin, the combustion rate of the mixture will decrease, and the heat transferred through the cylinder wall to the coolant after the mixture is burned will increase, resulting in a high engine temperature. The engine temperature is too high, which is prone to detonation and combustion.

4) Check if the fuel is contaminated.

The lower the designation (i.e., octane number) of gasoline, the less resistant the gasoline is to knock off, and the more susceptible the engine is to detonation combustion when using this gasoline as fuel. In addition, if impurities are added to the gasoline with a relatively high grade, it will also cause the anti-knock ability of the gasoline to decrease.

5) Check whether the engine knocks due to the failure of the engine cooling system.

The actual working temperature of the engine is determined by the heat generated by the combustion of the mixture per unit time and the heat emitted by the heat dissipation system, if the cooling system is faulty, the former will be greater than the latter, the temperature of the engine will be higher and higher, and the tendency to detonation and combustion will be greater and greater.

6) Check if the pressure of the cylinder is too much.

If the pressure of the cylinder is too high, the combustion rate of the mixture increases, and the likelihood of detonation combustion in the engine increases. The reason for the excessive pressure of the cylinder is that the cylinder head, piston or cylinder gasket model is not the same as the working volume of the cylinder and the cylinder pressure.

7) Check whether there is too much carbon deposits in the combustion chamber of the engine.

If a large amount of carbon deposits are accumulated in the cylinder, the hot spots formed by the carbon deposits may ignite the mixture in advance during the cylinder compression process, resulting in a sudden increase in the pressure in the cylinder during further compression, and detonation and combustion will occur. The causes of carbon deposition are as follows: the mixture is too concentrated, the ignition energy is relatively poor, the quality of gasoline is relatively poor, and the engine burns oil for some reason, etc., which can be checked separately.

8) Check if the EGR system is working properly.

If the exhaust gas recirculation system works within the working range, the system fails and cannot make the exhaust gas enter the cylinder to participate in the combustion, which will inevitably cause the combustion temperature of the mixture to rise, so that the engine will overheat and be prone to detonation combustion.

9) Check if the application and calorific value range of the spark plug are correct.

Hello, not a detonation. Look at the plug should be the water temperature.