Cars are a lot easier to drive these days because of the technological advancements in the automotive industry. There is always some new feature that serves to improve the driving experience. One of such features is the variable Assist Power Steering. What is the big deal about this feature? Another thing is how to tell if you have Variable Assist Power Steering? We will get right into that in a moment but let us take a look at how cars used to be a while back.
Years ago, driving a car required massive arms that came in handy when steering the car. This was mostly because of the way cars were built then. All that changed by 1951 when power-assisted steering was discovered. Over the years, car steering has undergone a lot of changes with car makers combining old and new technologies to arrive at modern steering systems like the variable-assist power steering.
What Is Variable Assist Power Steering?
Variable assist power steering is a system where the level of assist varies according to the vehicle’s speed. For example, with a ford variable-assist power steering, the car requires less assist and effort to steer while the speed increases. With variable-assist power steering, there is increased assist at low speeds and reduced assist at higher speeds. The variable-assist power steering allows drivers to maneuver their cars at low speeds using as little as their fingertips.
This is mostly achieved by regulating the pressure to the steering gear. With this system, the car’s wheel speed sensor and steering wheel rotation sensor signal the control unit, which regulates the pressure accordingly. The control unit does this by reducing the amount of fluid that flows into the steering gear system. This action increases the stability of the car and prevents it from careening or getting out of control.
The variable-assist power steering system employs the vehicle’s speed and the steering valve inlet pressure to effect a variation in the steering assist being provided. There is a system controller which is designed to receive speed and pressure data from the sensors. This controller generates a control signal for the variable-assist steering actuator which moves the fluid from the pump to the steering valve. This action affects the steering valve pressure, which controls the rack piston that changes the angle of the vehicle’s front wheels which are used to steer the car.
The EVO (Electronic Variable Orifice)valve is a key component in variable-assist systems. When the speed is below 40 MPH, the EVO becomes completely open so there is enough hydraulic fluid moves from the power steering pump to the steering unit. Thus providing maximum power assist. Once that speed is exceeded, a control module causes the EVO to restrict hydraulic fluid flow. As a result, the reduced assist improves stability on the road providing better control at such high speeds. For a variable-assist power steering to function, the EVO valve, control module and vehicle speed sensors have to be in good working condition. If any of these components malfunction, a loss of regulated assist occurs or (in extreme cases) the vehicle loses power assist.
Variable assist power steering systems are reliable as most of the system’s issues can be traced to the steering angle sensor. The downside is that the contacts can get worn out, resulting in wrong signals being sent to the control unit.
Read Also: Best Power Steering Pulley Puller
How to Tell If You Have Variable Assist Power Steering
Figuring out if you have variable-assist power steering can be a pretty challenging task for the uninitiated. A few might even have asked the question “what is magnetic variable-assist steering”.
In their defence, it is not easy to detect a variable-assist power steering by simply observing the vehicle’s performance. Why? The average vehicle steering gets lighter as the speed increases. Hopefully, at the end of the article, detecting the presence of a variable-assist power steering feature in your vehicle will be a lot easier for you.
So what is magnetic variable-assist steering? That’s the meaning for the acronym MSVA or the word Magnasteer. It is one of the earliest versions of the variably assisted power steering feature.
So if you have been wondering about your grand Prix variable-assist steering, you might have found the answers. First, you need to understand the kind of power steering system that your vehicle has. The next step is to look up your vehicle specifications from the dealership or online. You should be able to tell from your vehicle specifications if your vehicle has variable power assist. Be careful not to confuse this with the variable ratio.
If you can’t lay your hands on the specification information, you might have to try a visual search.
If your vehicle has a hydraulic power assist try using a droop flow pump. Check if it stays the same when there is an increased engine rpm. Check for the build tag that is usually under the lid of your trunk. If you find the code 1SC then you most definitely have a gm variable-assist power steering.
You might also want to check the underside of your spare tire cover. There should be a Service Parts Identification label. Check the label for the code NV7. If it’s there, then your car has variable power steering. However, the best way to find out is to carry out a test procedure. That way you get to confirm the presence(or not)of the variable-assist power steering.You also get to check if its still functional.