The steering angle sensor is a small but crucial part of your vehicle that can affect multiple important safety systems; yet many service professionals and drivers often overlook this component. Without appropriate calibration and working conditions, this simple sensor can cause serious problems.
Where is it? How does calibration work? What is the replacement cost? This article explains what you need to know about the steering angle sensor and some of the things you probably didn’t know.
What is a Steering Angle Sensor?
A steering angle sensor is an instrument that can assist a driver in controlling their vehicle. The sensor records the steering wheel angle and then relays a signal to the electronic stability control system in the vehicle.
The electronic stability control system uses the signal to adjust the braking and throttle of the vehicle. This ultimately can help mitigate possible accidents from occurring, or at the very least, minimize the effects of an accident.
In today’s vehicles, steering angle sensors are growing in prevalence and are generally viewed as a positive safety measure.
Where Can I Find the Steering Angle Sensor?
Inside the steering column (typically close to the steering wheel), there is a sensor cluster in which the steering angle sensor exists. The sensor cluster has a number of steering angle sensors to ensure the information is accurate.
The electronic speed control module needs two signals to confirm the orientation of the steering wheel.
Types of Steering Angle Sensors
There are two types of steering angle sensors: digital and analog. Digital sensors use a small LED light and process the data on the angle position and rate of turn. The analog version measures voltage differences to accomplish this.
The digital steering angle sensors will send data about the rate of turn, the angle of the wheel, the direction of turn, and various other things directly to the vehicle’s main computer.
If the steering angle sensor notices a difference between the steering wheel position and the direction the vehicle is heading, it will make a stability action to aid the driver in keeping control of the vehicle.
If your vehicle is in an understeer state, for example, the inside rear brake will be applied to correct the situation automatically.
If your vehicle is in an oversteering state, the stability system will apply the brake only to the outside rear wheel to steer the vehicle in the correct direction.
If any steering angle sensor fails or stops working, you should see a warning light on your dashboard alerting you of the issue. At that point, your stability system is in jeopardy of not working as intended.
Calibration and Diagnostics
In certain Toyota models, when you don’t have your steering position centered, you may need to disconnect or replace the car battery, which can result in the symptoms of the car trying to drive itself, and at times, you may also notice the output of the engine dropping.
If you are seeing any of these symptoms, you now need to use a good quality automotive scan tool, so you can get a reading on the faults.
Make sure you understand that not all scanners will call out the same fault. If your scan did not show any engine codes to show the reason for the power loss, you may have noticed that the SAS is showing a -560º reading as the steering is centered.
Why would that be?
When you disconnected the battery, did the wheels travel completely left or did the wheels remain in the center position?
It moved left, because it was in the garage where I was putting the battery in and to replace the battery I had to push the car out of a tight parking area.
After I took out the battery, the car had power, and then when I put the battery back in, and connected the battery, the wheels stayed left, but the steering angle sensor read zero.
In some Toyota vehicles, there will be a reset procedure that is known as “zero-point calibration.” Under the procedure, you simply disconnect the battery from the vehicle. When disconnected, the vehicle’s stability control module will not lose its calibration.
However, the system will have a recalibration for the most recent position, no matter what direction the wheels are pointing. This means that in this case, this position will receive a zero.
You then can use a scan tool to diagnose the issue, and highlight the stability system sensors in either a graph or a chart, while making sure to perform them on level ground. If you can not find decent level ground, an alignment rack will work.
Replacement Cost
The average price to replace a steering angle sensor is between $120-$550 total. The sensor itself will cost between $50-$400, and you will also be paying from $70-$150 for labor.
As with other sensors, the part price can vary widely depending on the type of device, year/make/model of vehicle, and if the part is OEM(Original Equipment Manufacturer) or aftermarket.
You’ll almost always pay less at an independent auto repair shop to replace this part than you will when going to a dealership.
You can attempt to replace this yourself, but due to the fact that you are usually dealing with an airbag and will need a specialty tool like a steering wheel puller, it’s probably best to let a professional do the job.