U0418 Fault Code

Long Description

Fault code U0418 is a communication-related fault code that is logged when invalid data from the brake system control module is received by one of the control modules onboard.

As its name indicates, the brake system control module is the onboard computer that is responsible for the operations of the vehicle’s brakes.

The various onboard control modules constantly converse with one another through messages that are sent through the controller area network (CAN) bus. A loss of data or an invalid message from one of these modules can cause noticeable issues.

These systems are found in modern cars and have become increasingly complex over the years. This can make a communication-related fault code like this very hard to fix without specialist expertise.

Not all vehicles can suffer from this code because it is a modern issue. However, more manufacturers are featuring these complex systems. Ford, Dodge, and Jeep are some of the most commonly searched brands alongside this code.

Other Signs of This Problem

Communication fault codes can come with some significant symptoms because of the importance of these onboard control modules.

The most obvious sign will be the presence of the Check Engine light on the dashboard.

There will also likely be some issues when it comes to the performance of the vehicle’s brakes as the brake control module is not functioning properly.

This could mean that the brakes do not function at all.

Be sure to look out for additional fault codes that can help pinpoint the cause of this issue. Related fault codes should always be addressed first when attempting to fix this fault code. Be sure to look out for codes like U0100, U0121, and U0129.

What Could Be The Problem?

Because this code indicates that invalid data has been sent from the brake control module, it is likely that there is a software issue at hand.

This can be caused by a faulty brake control module.

This can also be caused by a short circuit or open circuit in the brake control module circuit.

It is also possible that there is a similar electrical fault in the CAN bus network circuit.

In some cases, there may be a fault from another control module that is causing this issue. The anti-lock brake system is one of the most likely of these.

Fixes

In most cases, this fault code will require significant expertise to fix. This often means that help from a certified technician is required.

The first step in fixing this issue should be checking the brake control module. However, it may require specialized diagnostic equipment to even check if the controller is functioning properly. If the control module is faulty, it needs to be fixed or replaced.

Thereafter, it is important to check the brake control module circuit for any electrical faults.

Similarly, the CAN bus network should be checked for the same issues. Both wires need to be checked for open or short circuits. It is quite common that there is a short to ground or a short to power in the CAN bus circuit causing the code.

Seriousness

Fault code U0418 is a moderately serious issue. At worst, it can cause the brake control module to malfunction, which is obviously a very serious issue. However, this is not always the case, which reduces the severity of the fault code.

As a preventative measure, it is strongly recommended to have this fault code fixed immediately.