One of the most important and common problems related to BMW E39 that you can face as an owner of this generation of cars is the problem of bmw e39 brake pressure sensor fault or malfunctioning. We provide practical solutions to check it and learn how to replace it.

BMW E39 Brake Pressure Sensor Fault

The brake sensor, as the name suggests, is an upgraded system containing a sensor for the brake system in order to increase the level of car safety.
The brake sensor is a part of the ABS brake system. In order to be able to perform properly in protecting passengers, ABS brakes regularly receive wheel and vehicle Speed information and adjust their performance by evaluating them.
It is important and vital that each brake sensor works in harmony with each other. If the information is not received and sent to the main ABS module for analysis due to failure or problem of any of the sensors, or if it is contradictory, the performance of ABS brakes will suffer.

BMW E39 Brake Pressure Sensor Fault Symptoms

Symptoms of sensor failure (BMW E39 Brake Pressure Sensor Fault) include the following:

1. The ABS warning light turns on
2. Loss of Anti-lock brakes
3. Loss of stability and instability in the steering wheel
4. Pulsating brake Pedal when braking
5. Receiving the error code through the car’s central computer

The ABS warning light turns on

The ABS warning system tries to warn when the anti-lock brakes fail or have a serious problem by keeping the warning light on. At first it may simply cause the ABS warning light to come on.
However, the traction and stability control warning lights may also illuminate when other systems are not functioning properly. In other cases, it can even be expected that the wheel speed sensors will stop recording the speedometer.

Loss of Anti-lock Brakes (ABS)

One of the most dangerous signs that can indicate a problem with the car’s brake sensor is the complete failure of the anti-lock brakes.
In this case, the brake either loses its function in general, or the anti-lock function of the brake is felt to be out of order. This is one of the most dangerous signs of the loss of the BMW 39 brake pressure sensor.

Loss of Stability and Instability in the Steering Wheel

As mentioned, the coordinated information of the brake sensors is processed in the computer. But when one of the sensors or all the sensors fail, the ABS module actually fails. Failure of the ABS module leads to the loss of performance and stability of the car and lack of control over the traction stability of the car.

Pulsating brake Pedal when braking

When the wheels of the car move on a flat track, naturally, all ABS sensors reach a constant rate by measuring the speed of each wheel, and this constant rate is analyzed in the ABS module.
But when one of the sensors is faulty and out of reach, the system assumes that the vehicle has entered a slippery road or at least one of the wheels is spinning and the friction does not affect the wheel. . In this case, the ABS module tries to keep the car’s path stable with a reaction that is similar to kicks and hits on the brake pedal.

Error Code through the Car’s Central Computer

Scan tool (automotive) is one of the most important and practical devices that helps the repairmen to easily find out which of the sensors is out of the cycle through troubleshooting and using the general error codes related to the wheel speed sensor.

Based on this, the following error codes all indicate 3 general problems related to:

1. Sensor failure – 2. Disconnection of the wire connected to the sensor and 3. Or the sensor is dirty.

Error code: C0221 – C0225 – C0235 – C0222 – C0226 – C0236 – C0223 – C0227 – C0237 – C0229 – C0238

BMW E39 Brake Pressure Sensor Fault reset

Accurate troubleshooting is the most important step in resetting problems and solving sensor problems. Since the sensors in the cars are installed in a place where it is not possible to check it simply, one of the most important reasons for their failure can be due to the dirtiness of the sensor surface.

Since small magnetic units are used in the structure of the sensors, these sensors have a special ability to get dirty and accumulate scale when facing rainy weather and muddy paths. Therefore, if you see any cut in the wire or break in the sensor, make sure the surface of the sensors is clean.

BMW E39 Brake Pressure Sensor fault Fix

The E39 sensor is a cheap part, and in case of damage or failure, the best way is to replace it with a new sensor. There are two heads in each sensor piece.
The head with the sensor is connected to the wall of the brake pads and the other part of the sensor wire is connected to the output box connected to the ABS module.

1. The first step is to remove the car rim and tire. The location of the sensor does not allow checking without removing the rim.

2. Follow the sensor wire coming out of the pad as shown below. One end of each sensor wire is connected to the brake pad and the other end to a box connected to the car chassis.

3. First, to release the sensor, open the screw connecting the sensor wire to the input of the pad with a special wrench.

4. After opening the screw, remove the sensor and to open the other side of the sensor wire, refer to the opposite box connected to the car chassis. Open it

5. The other side of the wire, which is connected through a plastic clip, opens easily with a little pressure.

6. Remove the wire completely and connect the new sensor wire exactly like the old wire and fasten the end of the sensor wire in place .