Replacing the abs sensor Renault Logan

The Anti-Lock Brake System (ABS) prevents the wheels from locking up when braking, eliminating the risk of losing control of the vehicle and keeping the vehicle stable while driving. Due to the reasonable cost, this equipment is massively installed on modern cars. An important role in the operation of the system is played by sensors that are mounted on the hubs and record the speed of rotation of the wheels.

The purpose of the ABS sensor and the principle of operation

The ABS sensor is one of the three main components of the system, which also includes the control module and valve body. The device determines the blocking moment of the wheel by the frequency of its rotation. When this undesirable event occurs, the electronic control unit receives a signal from the sensor and acts on the valve body installed in the line immediately after the main brake cylinder.

ABS sensor with cable and connector

The block reduces or even stops the supply of brake fluid to the blocked wheel cylinder. If this is not enough, the solenoid valve will direct the fluid into the exhaust line, relieving pressure already in the brake master cylinder. When wheel rotation is restored, the control module depressurizes the valves, after which pressure in the hydraulic line is transferred to the wheel brake cylinders.

Each wheel of the car is equipped with an ABS sensor.

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How ABS works

With the advent of the latest braking system, the safety of the car during critical braking has increased. The system began to be installed in the 70s The ABS system includes a control unit, a hydraulic unit, wheel brakes and speed sensors.

The main device of Abs is the control unit. It is he who receives signals from sensors-sensors in the form of the number of wheel revolutions and evaluates them. The received data is analyzed and the system draws a conclusion about the degree of wheel slip, about its deceleration or acceleration. The processed information comes in the form of signals to the electromagnetic valves of the hydraulic unit that performs the control task.

Pressure is supplied from the master brake cylinder (GTZ), which ensures the appearance of a pressure force on the caliper brake cylinders. Due to the force of pressure, the brake pads are pressed against the brake discs. Regardless of the situation and how hard the driver presses the brake pedal, the pressure in the brake system will be optimal. The advantages of the system are that each wheel is analyzed and the optimal pressure is selected, which prevents the wheels from blocking. Full braking occurs due to the pressure in the brake system, regulated by the ABS.

This is the principle of ABS. On rear-wheel drive and all-wheel drive vehicles, there is only one sensor, which is located on the rear axle differential. Information about the possibility of blocking is taken from the nearest wheel, and the command about the required pressure is transmitted to all wheels.

The device that controls the solenoid valves can operate in three modes:

1. When the inlet valve is open and the outlet valve is closed, the device does not prevent the pressure from rising.
2. The intake valve receives the corresponding signal and remains closed, while the pressure does not change.
3. The exhaust valve receives a signal to reduce pressure and opens, and the inlet valve closes and the pressure drops when the check valve is turned on.

Thanks to these modes, pressure reduction and increase occur in a stepped system. If problems occur, the ABS system is disabled and the brake system works without it. On the dashboard, the corresponding indicator gives out about problems with the ABS.

The need to replace the device

A malfunction in the ABS system is signaled by a control lamp located on the dashboard of the car. In normal mode, the indicator lights up when the engine is started and goes out after 3-5 seconds. If the controller behaves incorrectly (turns on when the engine is running or flashes randomly when the car is moving), this is the first sign of a sensor malfunction.

The ABS light should turn off 3-5 seconds after starting the engine

In addition, a possible malfunction of the device is indicated by:

• the appearance of an error code on the on-board computer screen;
• constant blocking of the wheels during heavy braking;
• lack of characteristic vibration of the brake pedal when pressed;
• the parking brake indicator worked when the parking brake was released.

If any of these problems occur, you should run a full device diagnostic. In this matter, you should not trust highly paid car service masters - an independent check of the ABS sensor takes a little time and is carried out without expensive equipment. If the diagnostics reveals that the device has failed, it will have to be replaced with a new one.

Renault Logan 1.4 2006 Replacement ABS

Replacing the ABS sensor on the left rear wheel on your own.

If the abs sensor is faulty, then it does not send the necessary commands to the system, and the automatic locking system ceases to perform its functions - when braking, the wheels lock up. If the inscription on the dashboard lights up and does not go out, then you need to urgently contact the service.

The induction type sensor is an induction coil that works in conjunction with a toothed metal disk located in the wheel hub. Often the cause of the malfunction is a broken cable. It is this malfunction that we determine with the help of a tester, a soldering iron and pins for repair. The pins are connected to the connectors and the tester measures the resistance of the abs sensor, which should be within the limits specified in the instruction manual. If the resistance tends to zero, this indicates the presence of a short circuit. If it goes to infinity, then there is a break in the chain.

Then the wheel is checked and the resistance is checked, it should change, in this case the sensor is working. If damage is found during the inspection, they must be repaired. Breaks should only be connected by welding, not by twisting, to avoid new breaks, oxidation, etc. Each device has its own brand, wire color and polarity. We must adhere to these data.

If the sensor is broken, you need to learn how to remove the abs sensor and replace it. When choosing a device, you must first of all focus on quality.

For a complete diagnosis of sensors, it is necessary not only to check the contacts of the device with a tester, but also to ring all its wiring. One of the reasons for incorrect operation is a violation of the integrity of the wiring. If the devices are working properly, the resistance indicators are as follows:

• leg - right front abs sensor (7 25 ohms);
• insulation resistance level - more than 20 kOhm;
• leg - right rear abs sensor (6-24 ohms).

Many cars have a self-diagnosis system. In them, error codes are displayed on the information display, which can be decrypted using the operating instructions.

Diagnostics and replacement of the ABS sensor Renault Logan

Attention driver! Considering the complexity of the design, its importance in the brake system, it is not recommended to fix the malfunction on your own, replace the cable, contact plate, there are special services for these purposes.

The workshop manager, at his discretion, may use one or more diagnostic methods. In fact, there are many methods for determining the operability of a sensor; any generally accepted one can be used in your practice.

The easiest option: start the car engine, wait a few seconds until the lamp goes out, quickly press the brake pedal 5 times. Thus, the self-monitoring system is activated, a detailed report on the status of each of the ABS sensors will be displayed on the central instrument panel.

The second way: jack up the desired wheel with a jack, remove it from its regular place, disassemble the plastic casing under the wheel arch, check the quality of the connection of the contact plate on it. At the same time, check the fixation of the sensor on the rear wall of the brake cylinder.

Method number 3 - completely disassemble the sensor and check its performance on a special diagnostic stand.

To replace the sensor with a new one, you will need a new sensor, a set of tools, a jack, a screwdriver.

The wheel must be removed from the seat, disconnect the connector on the wheel arch, unscrew the ABS sensor from the back of the brake cylinder. A new one is installed to replace the faulty one. Assembly is carried out in reverse order.

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What can be malfunctions

If you hear a creaking sound when you press the brake pedal, then this is normal. This sound appears when the modulators are working. In the event of an ABS malfunction, the indicator on the instrument panel lights up after the ignition is turned on and does not go out, it continues to burn when the engine is running.

There are four ABS fault conditions:

1. The self-test detects an error and disables the ABS. The reason may be an error in the control unit or the presence of a broken wiring in the right rear abs sensor, or any other. Angular velocity measurement signals are not received.
2. After turning on the power, the ABS successfully passes self-diagnosis and turns off. The reason may be a broken wire, oxidation of the contacts, poor contact at the points of contact, a break in the power cable, a short circuit of the sensor to ground.
3. After turning on the ABS, it passes a self-test and detects an error, but continues to work. This can happen if there is an open in one of the sensors.

To troubleshoot, it is necessary to check the clearance, tire pressure, the condition of the wheel sensor rotor (comb). If the comb is chipped, it must be replaced. Check the condition of the devices and the cables that fit them. If these measures did not help, then the reason lies in the electronics. In this case, for accurate diagnosis, you need to get a code.

Some nuances

Replacing the sensors that are installed on the steering knuckles of the front wheels is much faster, since access to these parts is more convenient:

1. The car is raised on a jack, the desired wheel is removed.
2. The bolts that secure the sensor are unscrewed, and the device is removed from the seat.
3. The wiring harness is loose and the connector plug is disconnected.
4. Installing a new sensor is carried out in reverse order.

Attention! When installing a new sensor, make sure that dirt does not get into the place of its landing.

Before replacing the sensor, it is necessary to eliminate the causes that can lead to its malfunction. Particular attention should be paid to specific problem areas that each car model has. For example, all FORD vehicles manufactured before 2005 suffer from power outages resulting from frequent short circuits, and the quality of the wiring insulation is considered a critical point in the ABS system of these vehicles. In this case, it will be possible to repair the sensor instead of replacing it completely.

Fair pricing

In working with clients, we practice an individual approach, without templates and stereotypes. To increase the flow of customers, we hold promotions, discounts and bonuses.

In order to save a little on repairs, we offer our customers to buy spare parts directly in our store with their subsequent installation.

Checking the quality of work performed

After replacing the sensor, its performance is checked. To do this, it is enough to accelerate to a speed of 40 km / h on a flat and safe section of the road and brake sharply. If the car stops without pulling to the side, the vibration is transmitted to the pedal, and a specific sound is heard from the brake pads - the ABS system is working properly.

Today, you can easily find and buy any ABS sensor, from expensive original devices to analog parts at an affordable price. Remember that the competent selection of system elements plays an important role in its proper functioning. When choosing a sensor, read the manufacturer's instructions and make sure it fits the car, and this review will help you replace the device yourself.

Quality assurance

We provide a quality guarantee for all work performed. We document the originality of the products sold. We have been cooperating with the manufacturer of spare parts and components for a long time, so quality problems never arise.

When the customer provides his set of consumables, we check the quality and compliance with the established standards without fail. All questions and non-standard situations are resolved during personal conversations with the client.