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Power steering technology has significantly evolved since its initial integration into mainstream vehicles during the early 1950s. It revolutionized the driving experience by minimizing steering effort, regardless of the vehicle’s size. This advancement not only alleviated the tedium of driving but also enhanced maneuverability. And in this article, we will give it the spotlight.
The power steering warning light signifies a problem in the steering system. Fixing it entails checking power steering fluid levels, inspecting for leaks, and examining the power steering pump (among other things). If you need help with what to do next or the issue persists, seek professional help.
Whether the issue lies in low power steering fluid, power steering pump failure, or steering rack problems, diagnosing and rectifying the cause behind the power steering warning light is imperative. If uncertain or unable to resolve the issue independently, always seek aid from a skilled mechanic who can offer expert guidance and repair services.
Power Steering Warning Light Meaning
The power steering warning light is an idiot light set off by a flaw in the system providing steering assistance in a vehicle. It signifies various conditions and can have different implications, depending on the type of power steering system present in the given four-wheeler.
When illuminated, this warning light adopts a red or yellow hue. It appears as a steering wheel with an exclamation mark or displays the words’ Power Steering Assist Fault’ on the dashboard.
Currently, there are four different power steering systems. Here are some examples of vehicle makes and models under each category:
Hydraulic Power Steering (HPS):
Electric Power Steering (EPS):
- Ford Focus
- Chevrolet Cruze
Electro-Hydraulic Power Steering (EHPS):
- BMW 3 Series
- Mercedes-Benz E-Class
Electro-Mechanical Power Steering (EMPS):
- Volkswagen Golf
- Audi A4
Hydraulic Power Steering (HPS)
This system uses hydraulic fluid to assist with steering and is the first commercially available power steering system. It was awarded a patent in 1876 and later improved in 1902. However, it was not successfully fitted into an automobile until 24 years later by Francis Davis, the “Father of Hydraulic Power Steering.”
By definition, the HPS is a closed-loop system that uses pressurized hydraulic fluid to adjust the front wheel angle in response to steering input. It comprises essential components, including a hydraulic pump like a DriveStar 20-823 Power Steering Pump (view on Amazon), valves, cylinders, a reservoir, and a driver control mechanism — such as a rack and pinion or steering gearboxes.
The belt-driven hydraulic pump, in particular, plays a key role in generating necessary hydraulic pressure for power steering assistance. Combined, all these components work harmoniously to facilitate precise steering control and enhance one’s overall driving experience.
An illuminated power steering warning light in this system could signify an issue with any of the mentioned components. It could also mean low fluid levels or a leak in the system. Whenever this warning light illuminates in a hydraulic system, check the fluid level and inspect for leaks to determine if a top-up or repair is needed — and then go from there.
Electric Power Steering (EPS)
Unlike in HPS, this system relies on an electric motor to assist the driver. Typically, the latter is positioned on either the vehicle’s steering rack or steering column.
Meanwhile, sensors connected to the motor gauge the amount of rotational force or torque the driver applies to the steering wheel. Based on this input, the sensors determine the level of assistance required to turn the front wheels effectively.
In an EPS system, speed is the decisive factor in how much steering assistance it provides. In situations that require lower speeds (like parking), the steering wheel becomes remarkably easy to turn to make maneuvering more manageable.
Conversely, the steering wheel (view on Amazon) offers more resistance as the car accelerates, ensuring improved stability during higher-speed driving.
Functionally, an EPS system is simpler and easier to maintain than other power steering systems. Additionally, it does not require pressurized hydraulic fluid to work.
Instead, it relies on the electric motor, sensors, and power supply. EPS also makes for a more fuel-efficient steering system configuration since it draws power only when needed.
Electro-Hydraulic Power Steering (EHPS)
This third type combines hydraulic and electric components to provide steering assistance. While its hybrid nature makes for a more foolproof setup, the EHPS system means that there are more variables to rule out come the time that the system malfunctions.
That said, the power steering warning light may illuminate due to low hydraulic fluid levels, a malfunctioning pump, electrical issues, or a faulty sensor (to name a few).
When resetting the warning light, there is an obvious need to simultaneously inspect hydraulic fluid levels and electrical connections (which requires twice the technical savvy and effort).
Nonetheless, car owners appreciate that the system compensates for misalignment and rougher driving conditions. Adjusting the accuracy of power steering assistance is also made simpler through straightforward software updates.
On the flip side, issues with this kind of power steering system are more challenging to fix with standard parts and labor compared to a hydraulic or mechanical system. Furthermore, a certain level of expertise is required to diagnose and repair electrical issues and other faults attributed to a lit power steering warning light.
Electro-Mechanical Power Steering (EMPS)
Like the EHPS, an electro-mechanical power steering system utilizes an electric motor mated directly to the vehicle’s steering mechanism. It operates based on speed, is controlled electrically, and does not rely on hydraulic components. It functions like an on-demand steering system — engaging only when the driver requires it.
When the power steering warning light in an EMPS system illuminates, it typically indicates a fault with the electric motor or the steering angle sensor (view on Amazon). Either that or something is wrong with the vehicle’s electrical connections or power supply.
Causes & Symptoms
Gaining insight into the intricacies of the power steering system is vital for effectively addressing issues surrounding it. Fortunately, identifying the specific steering system in your vehicle can greatly assist in this process.
But to close in on a permanent fix, you should second this knowledge with a familiarity of the most prevalent causes behind the power steering warning light and its accompanying symptoms:
Some symptoms that your vehicle may exhibit alongside an activated power steering warning light:
- Unresponsive or rigid electric steering
- Hydraulic power loss characterized by increased steering effort
- Grinding noise when cornering
Inadequate or Leaking Power Steering Fluid
The power steering system relies on an adequate amount of fluid to operate properly and provide the necessary assistance to the driver. But when a decrease in power steering fluid level occurs due to inadequate fluid or a fluid leak, it can result in reduced hydraulic pressure within the power steering system and, subsequently, an illuminated warning light.
Malfunctioning Power Steering Mechanism
When there is a malfunction within the power steering system’s mechanical components, such as the power steering pump, rack and pinion, steering gearboxes, or other related parts, it will undoubtedly cause the power steering warning light to illuminate.
If this occurs, addressing the underlying cause promptly and outsourcing the task to a certified mechanic when necessary is crucial.
Power Steering Pump Failure
Several factors can cause power steering pump failure, such as belt issues, overheating, fluid contamination, wear and tear, and improper installation or repair of the component.
While most of these are due to negligence or performing repairs without the required technical know-how, others result from repeated use taking a toll on the component.
Steering Rack or Gearbox Issues
Steering rack or gearbox issues can contribute to power steering problems and potentially lead to the activation of the power steering warning light.
These issues include normal and premature wear and tear, inadequate lubrication, leaks, and internal failures. Some of them are characterized by erratic or inconsistent steering operation, so make sure that you keep an eye out for those unusual vehicle behaviors too.
Low Oil Pressure
Cars with HPS or EHPS systems rely on the engine’s oil pressure for proper operation. A sudden or severe drop in oil pressure may indirectly affect the power steering system’s functionality.
If you suspect this is triggering your power steering warning light, ensure your vehicle has no significant oil leak or a failing oil pump.
Depending on the specific vehicle and its electrical system design, a blown fuse can trigger the power steering warning light.
In some cars, the power steering system may be connected to a fuse that, when blown, can illuminate the power steering warning light. This should come as no surprise since a blown fuse signifies an electrical issue or an overload in the circuit.
Compromised Charging System
A charging system issue can indirectly affect the power steering system if it leads to an insufficient electrical power supply.
The power steering system, particularly EPS or EMPS types, relies on the electrical system for proper operation. So if the charging system is not functioning correctly, it can result in low battery voltage or inadequate power supply to the power steering system.
Defective Sensors or Sending Units
Faulty sensors or sending units can sometimes trigger the warning light. After all, the power steering system relies on various components (sensors and sending units included) to monitor and provide input for proper operation.
If any of these units become compromised, it can lead to incorrect readings or a lack of necessary information that would undoubtedly set off the power steering warning light.
Although indirectly, engine overheating (and its underlying causes) could be an aggressor to the power steering system. The reason is that overheating can cause power loss, affect the performance of various engine-driven components, and result in reduced power steering assistance — all of which can cause the power steering warning light to illuminate.
Another indirect trigger, a vacuum leak, can affect the power steering system and activate its warning light if it leads to engine performance issues. An engine experiencing a vacuum leak can translate to reduced overall engine power or irregular idling.
These issues could impact the operation of the power steering pump and other engine-driven components. Moreover, a decrease in engine power or unstable engine performance can result in diminished power steering assistance.
Loose Fan or Accessory Belt
For hydraulic-type power steering systems, a loose fan or accessory belt can indirectly affect the power steering system — but only if connected to the power steering pump.
The fan relies on the belt to operate and provide the necessary hydraulic pressure for power steering assistance. If it develops slippage or looseness, it can cause the power steering pump to operate less effectively, subsequently triggering the power steering warning light.
Compromised or Outdated PCM/ECM/ECU
A defective PCM/ECM/ECU can potentially trigger the power steering warning light, although it is less common. The reason is that the PCM/ECM/ECU is responsible for monitoring and controlling various systems in the vehicle (the power steering system included).
If found defective, it can disrupt the communication or control signals between the control module and the power steering components — leading to abnormal power steering operation or a fault in the system.
Resetting the Power Steering Warning Light
Provided that all component-related problem sources have been addressed, clearing the power steering idiot light is pretty straightforward. The process entails only five steps, with some variations contingent on the type of power steering system installed in the vehicle.
- Start the vehicle’s engine.
- Turn the steering wheel fully from left to right several times, and hold it for a few seconds each time.
- HPS/EHPS: Return the steering wheel to the center position.
- EPS, EMPS: Bring the vehicle to a complete stop and put it in park (for automatic transmission) or neutral (for manual transmission).
- HPS/EHPS: Shut off the engine.
- EPS, EMPS: Turn off the engine and wait for a few seconds.
- Restart the engine, and the power steering warning light should be reset.
For EPS, EMPS Systems
PCM/ECM Method or Hard Reset Technique
This procedure involves turning the ignition off and on three times. By doing so, the car’s system is primed on the 2nd and 3rd attempts, a valuable step in troubleshooting low power transmission fluid levels.
Moreover, It helps reset all the electricals in your vehicle while testing if the power steering warning light is intermittent. The catch? It only gets the job done for minor system hiccups.
For Broader Steering System Issues
OBD-II Code Reader
Although seldom, a power steering warning light may be synchronous with a Diagnostic Trouble Code or DTC. And before you can reset the warning light, you need to first clear the fault codes stored in the vehicle’s onboard computer system with a Foxwell NT809TS OBD-II Diagnostic Scanner (view on Amazon).
Examples of fault codes you may encounter while dealing with an activated power steering warning light include the following:
- C1513: Torque Sensor Circuit Malfunction/Deviation Excessive: This code indicates a malfunction or fault in the torque sensor circuit of the power steering system. A faulty torque sensor, wiring problems, sensor calibration errors, or other issues could cause it.
- C1608: Motor Overtemperature, Electric Power Steering Control Unit: This code suggests that the power steering motor has exceeded its safe operating temperature. It can be triggered by excessive power steering system usage, a malfunctioning motor cooling system, or a faulty temperature sensor (among other things).
- C2128: Power Steering Assist Loss, ECU Reset/Recovery Occurred: This code indicates a loss of power steering assist, which means the power steering system no longer provides assistance to the driver. It could be due to problems with the EHPS pump and the hydraulic system or an EHPS pump harness that is open or shorted.
Conclusion — Power Steering Warning Light Meaning and Fix
For those wondering if you can drive with a flawed power steering system, my response would be a “Yes” and “No.” “Yes” because, in most cases, the car has no problems running, even with an activated power steering warning light. And “No” because cruising on city streets while finding it difficult to turn is a recipe for disaster.
In worst-case scenarios where driving is the only option to get to safety or reach home, doing so for no longer than 18 miles at slow-to-moderate speeds is permissible. Otherwise, I strongly advise against it as it can damage the internal components of your power steering system.