Knock sensor VAZ 2112

The knock sensor (hereinafter DD) in the VAZ 2110 - 2115 model range is designed to measure the value of the knock coefficient during engine operation.

Where is DD located: on the stud of the cylinder block, on the front side. To open access for the purpose of prevention (replacement), you must first dismantle the metal protection.

The dynamics of vehicle acceleration, fuel consumption and idle speed stability depend on the serviceability of the DD.

Knock sensor on the VAZ 2112: location, what is responsible for, price, articles

Title/Catalog Number	Price in rubles
DD "Auto Trade" 170255	От 270
"Omegas" 171098	От 270
DAWN 104816	От 270
Auto-Electrician 160010	От 300
GEOTECHNOLOGY 119378	От 300
Original "Kaluga" 26650	От 300
Valex 116283 (8 valves)	От 250
Fenox (VAZ 2112 16 valves) 538865	От 250

Common causes of detonation

• Mixed low-octane fuels;
• The specifics of the engine design, the volume of the combustion chamber, the number of cylinders;
• Atypical operating conditions of technical means;
• Poor or rich fuel mixture;
• Incorrectly set ignition timing;
• There is a large accumulation of soot on the inner walls;
• Higher level of heat transfer.

How DD works

Functionality is based on the operation of the piezoelectric element. A piezoelectric plate is installed inside the DD case. During detonation, a voltage is created on the plate. The amount of voltage is small, but it is enough to create oscillations.

The higher the frequency, the higher the voltage. When fluctuations exceed the maximum range, the electronic control unit automatically corrects the angle of the ignition system in the direction of its decrease. The ignition works in advance.

When the oscillatory movements disappear, the ignition angle will return to its original position. Therefore, the maximum efficiency of the power unit is achieved under specific operating conditions.

If the HDD fails, the dashboard will display a "Check Engine" error.

Symptoms of DD malfunction

• The electronic engine control unit (ECU) on the dashboard signals errors: P2647, P9345, P1668, P2477.
• At idle, the engine is unstable.
• When driving downhill, the engine slows down, requiring a downshift. Although the rise is not long.
• Fuel consumption has increased for no reason.
• Difficulty starting the engine "hot", "cold";
• Unreasonable stop of the engine.

How to check the knock sensor, replace it yourself with a VAZ 2112

A message about the presence of a system error on the board does not guarantee a 100% malfunction of the DD. Sometimes it is enough to confine ourselves to preventive maintenance, purging, and the equipment's performance is restored.

In practice, few of the owners know and use it. Most often it is replaced with a new one. This is not always economically feasible.

The sudden inclusion of DD occurs after washing the car, driving through puddles, in rainy weather. Water penetrates inside the controller, the contacts close, a power surge occurs in the circuit. The ECU considers this a system error, giving a signal in the form of P2647, P9345, P1668, P2477.

For the objectivity of the data, conduct a comprehensive diagnosis using digital equipment. In "garage conditions" use a device such as a multimeter. The sensor is available to most motorists.

In the absence of a device, it can be purchased at any car shop, car market, online catalogs.

Step-by-step diagnostics

• We install the car on the viewing channel. Alternatively, we use a hydraulic lift;
• Open the hood to improve visibility;
• From under the bottom we unscrew six screws - fastening the metal protection. We remove it from the seat;
• DD is pre-installed under the exhaust manifold housing. Gently pry off the block with cables, turn off the ignition;
• We bring the conclusions of the multimeter to the limit switches;
• We measure the actual resistance, compare the results with the standards specified in the instruction manual;
• Based on the data obtained, we make a decision on the advisability of further use of the equipment.

Guide to replacing a knock sensor on a VAZ 2112

Required materials, tools:

• Open-end wrench to "14";
• necklace, lengthening necklace;
• New DD;
• Additional lighting as needed.

Regulation:

• We install the car on the viewing channel;
• Disconnect the battery power terminals;
• We unscrew and remove the metal protection of the oil pan;
• We disconnect the block with wires by carefully prying the terminals with a flat screwdriver;
• We unscrew the nut with a key - the lock, remove the DD from the seat;
• We replace the equipment with a new one;
• We put the block with wires;
• We fasten the metal protection.
• We assemble the structure in the reverse order. Replacement completed.

The average service life of a DD is unlimited, but in practice it does not exceed 4-5 years. The duration of the resource depends on the conditions of use, the climatic features of the region, the frequency of operation.