Steering Assist Fault Service Required F150 [Explained]

The occurrence of a “steering assist fault service required” message can be attributed to several factors such as low voltage from the vehicle, faulty steering motor, and faulty steering angle sensor. In addition, faulty fuse, software issues, and faulty wheel alignment are also known to trigger such notifications.

This is an overview of the steering assist fault service required for F150 concerns. Please proceed to the subsequent instructions for a more comprehensive guide.

9 Reasons Behind Ford F150 Steering Assist Fault Service Required

Some of the electrical, mechanical, and software issues are responsible for the notification “steering assist fault service required”. Have a look at the table below for a quick overview of these issues and solutions.  

Reason Diagnosis Solution
Low voltage from the vehicle Check the battery with a multimeterReplace the battery
Faulty steering angle  sensor Check the sensor with diagnostic tools Replace the steering angle sensor
Faulty torque sensor Check the sensor with diagnostic tools Replace the torque sensor
Faulty fuseVisually inspect the 105-number fuseReplace the fuse
Software issueTake assistance from an expertReset the power steering system
ECM has a bad connection with the steering assistant module Check the connection Fix the connection
Faulty wheel alignment Inspect the alignment of the wheelFix the alignment 
Low power steering fluid levelCheck the fluid levelRefill fluid 
Bad power steering pumpCheck the power steering pumpReplace the power steering pump

Now, the following section will be a brief discussion of these issues and their solutions. 

Reason 1: Low Voltage From The Vehicle 

In Ford F150, the power steering system relies on the power steering motor to provide the necessary assistance to turn the wheels. The power steering motor operates within a specific voltage range of 8 V to 16 V.

If the voltage supplied to the power steering motor falls below this operating range, it can cause the power steering system to malfunction and display a steering assist fault. This can happen due to a weak battery or a faulty alternator that fails to provide enough voltage to the power steering motor.

When the power steering motor receives low voltage, it may not function properly, resulting in reduced or no power steering assistance, making it difficult to turn the wheels.

Diagnosis: Check the Battery Voltage With a Multimeter 

To diagnose the battery voltage of a Ford F150 with a multimeter, turn off the engine and all electrical components. Set the multimeter to DC voltage and connect the black probe to the negative terminal and the red probe to the positive terminal of the battery. Read the voltage on the multimeter display to determine the state of charge of the battery. 

A fully charged battery should read around 12.6 volts, while a voltage of 12.4 volts is considered 75% charged and still capable of starting the engine. If the voltage drops to 12.2 volts without the engine running, it indicates a bad battery that may start the engine but cannot hold a charge. It’s important to keep in mind that a battery’s voltage can vary based on factors such as temperature, age, and load, so testing the voltage several times under different conditions is recommended for accurate readings.

Solution: Replace the Battery

Replacing the battery of the Ford F-150 is a challenging task, that’s why it’s recommended to consult an automobile expert to do this. However, if you are a DIY person you can refer to the video below for a visual guide Ford F150 Battery Replacement 2015-2020

Reason 2: Faulty Steering Angle Sensor 

The steering angle sensor (SAS) is a component of the steering system in the Ford F150 that measures the position and rotation of the steering wheel. This information is used by the steering control module to determine the direction and speed of the vehicle and to provide steering assistance as necessary.

A faulty steering angle sensor can cause a “steering assist fault” warning to appear on the dashboard of the Ford F150. This can happen when the sensor fails to accurately measure the steering angle, or when it sends incorrect signals to the steering control module.

Diagnosis: Check With an OBD Scanner Tool

To check if the steering angle sensor is bad you need to diagnose it with an OBD scanner tool. For the guide on how to do it watch the video HOW TO TEST STEERING ANGLE SENSOR FORD FOCUS FIESTA ESCAPE EDGE F150 FUSION EDGE F 150 TRANSIT

Solution: Replace the Steering Angle Sensor

Replacing the steering angle sensor on a Ford F150 is a complex process that requires specific tools, skills, and safety precautions. The following steps will guide you through the process:

Tools Needed

  1. Allen wrench set SAE / Metric
  2. Boxed end wrenches
  3. Cross tip screwdriver
  4. Dental picks
  5. Flathead screwdriver
  6. Protective gloves
  7. Ratchet w/metric and standard sockets
  8. Safety glasses
  9. Slip joint pliers
  10. Snap ring pliers
  11. Steering wheel puller kit
  12. Torque bit set
  13. Wheel chocks

Step 1: Disconnect the Battery

Open the hood and disconnect the ground cable from the battery’s negative post.

Do not reconnect the battery or attempt to apply any power to the vehicle while replacing the steering angle sensor.

Step 2: Remove the Dash Panel

Use a cross-tip screwdriver to remove the mounting screws to the dash panel. Then pull off the dash panel to access the mounting nuts to the steering wheel base.

Step 3: Remove the Steering Wheel

Remove the mounting nuts located in the back of the steering column. Next, disconnect the power wire to the horn button and the yellow power wire to the airbag. Then remove the mounting nut or bolt to the steering wheel and use a steering wheel puller kit to remove the steering wheel assembly.

Step 4: Remove the Tilt Section

Remove the tilt lever with a pair of slip-joint pliers. After that remove the plastic covers to the steering column by removing the mounting screws on each side.

Then release the pin in the pinhole, turn the key to the start position, and remove the ignition tumbler from the steering column. And, remove the clock spring and any brackets that may interfere with the clock spring removal.

Step 5: Disconnect the Electrical Harnesses

Disconnect the connectors in the lower portion of the steering column. Then take out the multifunction switch and disconnect the electrical harness from the switch.

Step 6: Remove the Snap Ring

Use snap ring pliers to remove the snap ring that connects the tilt section to the steering shaft. Use a large flat screwdriver to remove the tilt spring.

Step 7: Remove the Steering Angle Sensor

Remove the mounting screws holding the tilt section in place and slide the tilt section out of the vehicle. Next, unplug the harness to the old steering angle sensor and remove it from the steering shaft.

Step 8: Install the New Steering Angle Sensor

Hook up the harness to the new steering angle sensor and install it onto the steering shaft.

Step 9: Reassemble the Steering Column

Reinstall the tilt section back into the vehicle and torque the nut down to finger tight and 1/8 turn. After that, install the mounting screws securing the tilt section to the steering column. Next, install the tilt spring and snap ring onto the steering shaft. 

And then, reinstall the clock spring, multifunction switch, and connectors in the lower part of the steering column. Finally, install the key tumbler into the steering column, plastic covers, and the tilt lever.

Reason 3: Faulty Torque Sensor 

A faulty torque sensor can cause the EPAS system in a Ford F150 to give uncoordinated steering input, leading to inconsistent and unpredictable steering. 

The “Steering Assist Fault” warning message may appear on the dashboard, and while fatal accidents as a result of EPAS failure are uncommon, it’s important to have the faulty sensor diagnosed and repaired to ensure proper steering functionality.

Diagnosis: Check The Sensor With Diagnostic Tools

To diagnose the torques sensor you need to locate the sensor first. It’s typically located in the steering assistance module. This diagnostic process is identical to the steering angle sensor diagnosis so follow that process.

Solution: Replace the Steering Torque Sensor

Even though the replacement process of the torque sensor is almost identical to the replacement of the steering angle sensor, it’s more challenging. Due to that, we recommend consulting a professional automobile mechanic to do this. 

However, if you are a DIY person, you can refer to the video below to do this on your own. Replacing and calibrating the torque sensor 

Reason 4: Faulty Fuse

A faulty fuse in the Ford F150 can cause the steering assist fault to appear on the dashboard. The power steering system in the F150 uses an electric motor to assist with steering, and this motor requires electrical power to function properly. 

If the fuse that supplies power to the steering motor is faulty or blown, the motor won’t receive the necessary electrical power. Also, the steering assist system will not function properly.

Diagnosis: Visually Inspect the Fuse

To inspect the fuse for the power steering assist in a Ford F150, you will need to locate the fuse box that contains the fuse for this system. As mentioned in the quoted statement, the fuse for the power steering assist in the F150 is usually labeled as fuse number 105 and is located at the very bottom of the fuse box on the left side.

Once you have located the fuse, you will need to check whether it is blown or not. To do this, you can use a multimeter or a fuse tester.

 If you do not have access to either of these tools, you can visually inspect the fuse by looking for signs of damage, such as a broken filament or a discolored appearance. 

If the fuse is blown, it will need to be replaced with a new fuse that has the same amperage rating as the original fuse. 

Reason 5: Software Issue

There can be several reasons why a Ford F150 may display a “Steering Assist Fault” message on the dashboard. However, one possible cause could be related to software issues in the vehicle’s electronic power steering system.

Electronic power steering systems use software to control various components such as sensors, motors, and controllers. If there is a glitch or error in the software, it can cause the power steering system to malfunction, resulting in the “Steering Assist Fault” message being displayed.

Diagnosis: Take Assistance From An Expert

To determine the software glitch you need a high knowledge of software and automobiles. To detect this issue you should consult a professional automobile mechanic. However, resetting the power steering system sometimes can resolve this issue.

Solution: Reset The Power Steering System

To reset a power steering assist fault warning in a Ford F150, restart the car 2-3 times. However, if the warning persists, it’s best to take the car to a qualified mechanic for a proper diagnosis and repair.

Reason 6: ECM‘s Bad Connection With The Steering Assistant Module 

A bad connection between the Electronic Control Module (ECM) and the Steering Assistant Module can cause a malfunction in the steering assist, leading to a “Steering Assist Fault” warning message on the dashboard of a Ford F150. This can occur due to a loose or corroded electrical connection or a damaged wiring harness.

Diagnosis: Check the Connection Between ECM and Module

To check the connection between the ECM and assisted steering module in a Ford F150, follow these steps:

Step 1: Locate the power steering control module, which receives inputs from a steering position sensor and a steering torque sensor mounted on the steering rack input shaft.

Step 2: Check the connections between the power steering control module and the steering position and torque sensors. Make sure they are clean and secure.

Step 3: Check the connection between the power steering control module and the ECM. Ensure that the connection is clean and secure and that there are no loose or broken wires.

Step 4: Use a scan tool to check for any fault codes related to the power steering system. This will help diagnose any potential issues with the connection between the ECM and the power steering control module.

Step 5: If there are no fault codes and the connections are secure, consider reprogramming the power steering module’s software to fine-tune the steering feedback functions.

Solution: Fix the Connection

Fixing the connection between ECM and the power steering module is a difficult task. Any sort of mistake can further trigger the issue. So, it’s advisable to consult an expert to do this. 

Reason 7: Faulty Wheel Alignment 

Faulty wheel alignment can cause Steering Assist Fault in Ford F150 by causing the electronic power steering (EPS) system to malfunction. Misaligned wheels can cause the sensors in the EPS system to send incorrect signals, resulting in the system misinterpreting the steering input and causing the vehicle’s power steering to fail.

Diagnosis: Inspect the Alignment of The Wheel

Wheel misalignment inspection is not a very difficult task. To check the alignment and realign the wheel correctly, you may need the assistance of an automobile mechanic. However, you can refer to the video below if you are a DIY person.

Reason 8: Low Fluid Level

The hydraulic power steering system in old Ford F150 trucks relies on hydraulic fluid to provide the necessary pressure to assist with steering. If the fluid level in the power steering system drops too low, it can cause a variety of issues, including a steering assist fault.

When the power steering system doesn’t have enough fluid, it can cause the power steering pump to work harder than normal, which can lead to increased wear and tear on the system. This can cause damage to the pump, which in turn can cause the power steering system to malfunction and produce the steering assist fault warning.

Diagnosis and Solution: Check the Fluid Level and Refill the Fluid

Checking the fluid level in the power steering pump and refilling it is quite an easy process. We’ve got this covered in another article regarding this factor. So, refer to the relevant section in the power steering problems article.

Reason 9: Bad Power Steering Pump

A faulty power steering pump can cause a “Steering Assist Fault” message to appear on the dashboard of your Ford F150. The power steering pump is responsible for providing hydraulic pressure to the power steering system, which assists in turning the wheels.

If the power steering pump is failing or not working properly, it can result in a loss of power steering assistance, making it harder to turn the wheels. This can trigger the “Steering Assist Fault” message on the dashboard of your Ford F150, indicating that there is an issue with the power steering system. 

If you don’t find any other issues regarding the message then it’s definitely for the power steering pump failure. In this case, you need to replace the power steering pump.

Solution: Replace the Power Steering Pump

Replacing the power steering pump is a complicated process. It’s always recommended to consult an automobile expert to do this. However, if you want to do it on your own you can refer to the video below for guidance. 

Can You Still Drive F150 With Steering Assist Fault Service Required Notification?

It is technically possible to drive a car with a steering assist fault service required notification, but it is not recommended. The issue may not improve, and the electric power steering system is drawing excess power from the battery, causing further problems. It is advisable to get the car serviced as soon as possible. 


Can Low Tire Pressure Cause Steering Issues?

Yes, low tire pressure can cause steering issues as underinflated or deflated tires increase forward drag and lateral steering effects on vehicles, which can lead to driver loss of control and vehicular accidents. It’s important to regularly check and maintain proper tire pressure to ensure safe and efficient driving.

Can You Disable Electric Power Steering?

Yes, it is possible to disable electric power steering by pulling the electric power steering fuse or relay. However, this will make the steering much heavier, especially at slower speeds, but the car will still be drivable.

Does Power Steering Fail Suddenly?

Yes, power steering can fail suddenly if there is a problem with the power steering belt, which connects the engine to the power steering pump. Any damage to the belt, such as stretching, fraying, or breakage, can cause immediate failure of the power steering system. It is recommended to have the power steering belt checked regularly and replaced if there are any signs of wear or damage.


That’s all about the steering assist fault service required F150. Hopefully, this discussion will be handy for you to get rid of the issues that trigger this message on the dash.  

However, don’t drive your vehicle if this message persists without fixing the issues as it has a safety threat. Cheers!

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William Baldwin

This Is William Baldwin, The Founder & Managing Editor of this website. Me and my team share automotive tips, tricks, and news

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Talha Atta

Talha Atta, a Mechanical Engineer and experienced technical content writer and editor at with a passion for the automotive industry.