Steering Assist is Reduced (Meaning, Causes, and Solution)

What does it mean when you see the steering assist is a reduced error message? We are going to be looking at that in this post and see how to deal with this particular issue when we come across it.

You’re driving down the street and you notice that your steering has become stiff and you are finding it difficult to control your vehicle. Next, you see “steering assist is reduced. Drive with care” on your dash. What does it mean and how do you handle it?

In short, The Steering Assist Reduced error message is a result of Engine Control Module (ECM) providing an inaccurate coolant temperature reading. The job of the ECM is to read the temperature of the coolant and regulate its temperature accordingly. When the coolant temperature gets too low, it causes the grease in the steering module to harden leading to a stiffer steering wheel.

When this happens, steering assist is then engaged providing more power to the steering wheel.

Before power steering was invented, you really needed to be in good shape in order to drive a vehicle, especially the bigger trucks. It took a lot of effort to keep a vehicle under control.

However, with the advent of power steering, this became a thing of the past. Power steering was a revelation to say the least. It is now standard on all vehicles. Further innovations have been made over time which includes steering assist. This is a mechanism that allows for additional assistance to the power steering under specific conditions.

What is Steering Assist?

The power steering control module (PSCM) is responsible for calibrating the power steering system. When temperatures are too low, the grease lubricating the power steering system will harden causing the steering to become stiffer.

When this happens, the PSCM activates the power steering assist which compensates the stiffness by adding more power to the power steering. This happens smoothly when the temperature sensors provide accurate readings.

What Does the Message Assist Reduced Mean?

The reduced error message happens when coolant temperatures fall too low and the sensors do not detect this, it means that the steering assist will not be engaged leading to you seeing the steering assist is reduced error message.

This problem is often not caused by a physical defect on your vehicle but just a case of calibration. When this happens, you need to clear any error messages as we will show you later in the article instead of replacing any physical parts.

This is a common mistake most people who experience this problem make. They rush to replace parts and end up losing a lot of money in the process.

This is not necessary at all. Another reason why the message may remain on the display screen even when there is no actual issue is when you change the battery or unplug one component or another in your car.

History codes that would have been stored in the system may appear as current. In the case of the steering assist message, you may find that the steering is working fine even though the error code is coming up.

Though it may not be absolutely the case, there is a high probability that there isn’t an actual problem but the error code would have been triggered by one thing or the other.

You will need to make certain through a systematic diagnosis and troubleshooting approach that eliminates any potential guesswork. In the next section, we will be looking into that.

How Do You Fix Steering Assist Reduced?

The nature of this error with calibration can potentially mislead because of the nature of the steps needed to fixing it. They include looking into the customer’s complaint.

The next step would be to follow diagnostics best practices. For the best chance at a correct diagnosis, follow these steps: Analyze and record diagnostics errors in all modules.

Clear all diagnostic errors that come up. If diagnostic errors do not clear, it means there is a fault in the vehicle that needs to be looked into and repaired. Reprogram the Powers Steering Control Module with the latest configurations.


The “Steering assist is reduced” is an error that comes because of a disruption in the communication between modules and is thrown out by the power steering control module. Once the error has been thrown out even if the problem has been rectified it still reads like a current problem.

It is a DTC U0415 error and usually presents in the GM’s Sierra, Tahoe, and Silverado models. In the event that this error persists, it is advisable that you take your car into the shop and have an expert look it over. However, there is little likelihood that any replacement of parts will be necessary as the error is more of an issue with the algorithm than a physical component of the vehicle.



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