Car speed sensor Lada Granta

The speed sensor (DS) is located in the gearbox and is designed to measure the exact speed of the vehicle. In the Lada Granta control system, the speed sensor is one of the main devices that maintain the machine's performance.

Principle of operation

Such a DC is found on all VAZ vehicles, and Grants' 8-valve engine is no exception. The work is based on the Hall effect. Each of the 3 contacts located on the sensor performs its own function: pulse - is responsible for the formation of pulses, ground - turns off the voltage in case of leakage, power contact - provides current transfer.

The principle of operation is quite simple:

• A special mark located on the sprocket generates impulses when the wheels of the car move. This is facilitated by the pulse contact of the sensor. One revolution is equivalent to registering 6 pulses.
• The speed of movement directly depends on the number of generated pulses.
• The pulse rate is recorded, the data obtained is transmitted to the speedometer.

As speed increases, heart rate increases and vice versa.

How to identify a malfunction

Situations in which it is necessary to replace the sensor occur infrequently. However, if you encounter certain problems, you should pay attention to them:

• The discrepancy between the speed of movement and the speed indicated by the speedometer needle. It may not work at all or work intermittently.
• Odometer failure.
• At idle, the engine runs unevenly.
• There are interruptions in the operation of the electric power steering.
• Spikes in gas mileage for no real reason.
• The electronic accelerator pedal stops working.
• Engine thrust is reduced.
• A warning light will illuminate on the instrument panel to indicate a malfunction. To determine that this particular sensor has failed, diagnostics by error code will be allowed.

To understand why these symptoms appear, you need to know where the speed sensor on the Lada Grant is located. From a technical point of view, its location is not quite correct, which causes problems in measuring speed. It is located quite low, so it is negatively affected by moisture, dust and dirt from the road surface, pollution and water violate the tightness. Errors in the operation of the DS often lead to failures in the operation of the entire engine and its main components. A defective speed sensor must be replaced.

How to replace

Before removing the speed sensor from the Lada Grant, it is worth checking the operation of the electrical circuit. Perhaps the problem is an open or discharged battery, and the sensor itself is working. To do this, you must perform the following steps:

1. After turning off the power, it is necessary to check the contacts, in case of oxidation or contamination, clean them.
2. Then check the integrity of the wires, special attention should be paid to bends near the plug, there may be breaks.
3. The resistance test is carried out in the ground circuit, the resulting indicator should be equal to 1 ohm.
4. If all indicators are correct, check the voltage and grounding of all three DC contacts. The result should be 12 volts. A low reading may indicate a faulty electrical circuit, a missing battery, or a faulty electronic control unit.
5. If everything is in order with the voltage, then the most effective way to check the sensor is to find it and change it to a new one.

Consider the sequence of actions to replace the DS:

1. To get started, first of all, disconnect the tube connecting the air filter and the throttle assembly.
2. Disconnect the power contact located on the sensor itself. To do this, bend the latch and lift it up.
   
   
3. With a key of 10, we unscrew the bolt with which the sensor is attached to the gearbox.
4. Use a flat blade screwdriver to hook and pry the device out of the hole in the gearbox housing.
   
   
5. In the reverse order, the installation of a new element is carried out.

The removed DS can be tested to see if it is repairable. In this case, it is enough to clean it, dry it, go through the sealant and install it back. For a clean or new old sensor, it is better not to save on sealant or electrical tape in order to protect it as much as possible from dirt and moisture.

After performing the replacement, it is necessary to delete the error that is already registered in the memory of the control system. This is done simply: the “minimum” battery terminal is removed (5-7 minutes are enough). Then it is put back and the error is reset.

The replacement process itself is not complicated, but laborious in most cases, because few people know where the speed sensor is located on the Grant. But the one who once found it will be able to replace it quickly enough. It is more convenient to replace it on a flyover or inspection hole, then all manipulations can be carried out much faster.