What is a steering angle sensor? What are the symptoms for steering angle sensor (SAS), failure? How does the steering sensor work? How do I reset the steering angle sensor ?….?
What is the Steering Angle Sensor?
Innovation is driven by technology, especially in the automotive sector. In the past drivers were forced to use skill and luck when faced with the decision of whether to avoid an accident. In recent years, the automotive industry has created advanced stability control systems to ensure that the driver doesn’t lose control of their vehicle when performing sudden steering maneuvers. Each manufacturer has its own name for this advanced security system. Some of the most popular are ESP, ESC and RSC. The names are distinctive, but the primary functions and components of this system are almost identical.
The following sensors are the most important in the ESP / ESC systems:
- – Deviation rate sensor
- – Sensor for lateral acceleration
- – Wheel speed sensor
- – Steering angle/steering torque sensor
These sensors are interdependent and provide information to the Electronic Stability Program module (ESP), such as speed of rotation or traction control. The steering wheel angle sensor must be reset or calibrated whenever there is any change to the steering system. This is because the sensors need to transmit correct information.
Today’s vehicles are equipped with variable effort power steering, such as LKA (Lane Keeping Assistance), EPS(Electric Power Steering), and ADAS [Advanced Driver Assistance Systems]) and semi-autonomous driving system based on steering-correct data.
How does the Steering angle sensor (SAS) work?
The steering angle sensor, also known as the SAS, is used to determine where the driver wants the vehicle to go. It matches the steering wheel with the vehicle’s tires. There may be multiple steering angle sensors in a vehicle’s steering column or front suspension. Multiple sensors are needed to measure the steering angle. This is crucial for stability control. To ensure accuracy, the two sensors are combined and compared to each other.
There are two types: digital and analog steering angle sensors. The digital version is the most common. Digital sensors use voltage differences to calculate the steering angle and direction. Analog sensors measure the angle of the input with an LED light.
An analog sensor generates a voltage signal between 5 and 0 volts when the wheels turn fully. Most vehicles produce positive voltage when they turn right, and negative voltage when they turn left. The sensor sends information to the ESP module. The advanced algorithm used by the ESP module calculates the exact angle between the steering wheel’s position and the steering wheel’s angle using a precise method.
The steering angle sensor tells you how fast your steering wheel turns. At low vehicle speeds, quick steering is normal. However, it is not common at highway speeds. The ESP will detect a driver who steers fast at highway speeds as an indication of losing control.
The ESP system gathers information from many sensors, as we have already mentioned. The ESP module compares information from sensors like wheel deflection, lateral acceleration and steering angle with the programmed information. The ESP system will activate if there is inconsistency and assist the driver in maintaining control.
If the ESP detects a loss in steering control, it will signal the powertrain control module to reduce engine torque. The PCM will reduce the vehicle’s speed by decreasing the throttle. If it fails to regain control, it will activate ESP/ABS. The correct wheels will have brakes applied to stop the vehicle skidding. (For example, if the vehicle’s understeer is detected, the rear brake is activated.
Steering Angle Sensor Malfunction Symptoms
The steering angle sensor is built to last for the life of your vehicle. Like any sensor, the steering sensor can be damaged by many things. It can show signs and symptoms when it is failing or begins to die.
The following are some of the symptoms of a bad steering angle sensor:
Traction Control and Engine Malfunction Lights On
The sensor will stop collecting or sending information if it fails. If the data sent from the steering angle sensor and the ESP is inconsistent, a fault code is stored within the engine control module (PCM/ECM). The warning light in the instrument cluster then turns on. The traction control light is what this warning light indicates for most cars. However, some cars may also indicate the check engine or additional light. These warning lights notify the driver that the vehicle’s ESP has been disabled and needs to be serviced.
Other warning lights, such as ABS and airbag light, may also be visible. If the wires of the steering angle sensor are damaged, the airbag could also be a problem.
Loose and playing steering wheel
The majority of modern cars have an electric power steering system (EPS). To ensure that the electric power steering works properly and that the power steering pump knows when to start, it is important to measure the angle of the steering wheel.
The information collected and sent to the ESP module by the steering angle sensor will not be accurate if it is damaged or incorrectly installed. The electric power steering module could make an error in its adjustments. This can cause the steering wheel to feel loose or playy. This is due to the fact that the steering input you provide is not being sent properly to the wheels.
You should contact a mechanic if your steering wheel feels loose or if it isn’t responding correctly.
The steering angle sensors of today are connected to many points in the steering system. Many mechanics forget or fail to calibrate the steering angle sensor after performing any kind of intervention. After the steering components have been aligned and replaced, the steering angle sensor must be reset. Some vehicles require the steering angle sensor to be reset after the battery has been disconnected or replaced. It could cause the check engine light and traction control light to turn on, which can lead to a misaligned steering column. If you have any of these symptoms, your mechanic should inspect the steering angle sensor.
Reset Steering angle sensor
ESP systems are found in millions of modern cars. They require calibration of the steering angle sensor after any intervention. Depending on your vehicle, there are three ways to reset the steering sensor.
Self calibration
Some vehicles can automatically calibrate themselves by turning the key and moving the steering column from the lock position to middle position. A few vehicles have a set number of commands that must all be followed in order for calibration to take place.
Take a test drive
Modern vehicles equipped with wheel speed sensors may calibrate the steering angle sensor simply by driving straight up the highway for a few second.
Resetting the computer using a diagnostic tool
Some vehicles have the ability to reset the steering angle sensor using the diagnostic tool.
