U0418 – Invalid data received – brake system control module

By Bojan Popic (Contact Me)
Last Updated 2023-04-19
Master Mechanical Engineer

Table of Contents

1. What Does Code U0418 Mean?
2. Where is the U0418 sensor located?
3. What are the common causes of code U0418?
4. Get Help with U0418

What Does Code U0418 Mean?

OBD II fault code U0418 is a generic trouble code defined as Invalid data received – brake system control module. This code is set when the signal coming from the brake module seems invalid or implausible.

Almost all modern cars have several control modules connected through a CAN-Bus, which is short for Controller Area Network. This high-speed connection allows any module to share relevant information with all other modules.

Let’s take the brake control module, to which the U0418 trouble code refers, as an example. It continuously monitors the signal from all four wheel speed sensors and, if necessary, takes appropriate action. For instance, if the driver presses the brake too hard and one of the wheels locks up, it will relieve the braking pressure, which is more commonly known as Antilock Brake System.

Or, if it detects the vehicle is sliding sideways, the brake module will activate one or more brakes to get it back on track. And simultaneously, it will pass on this information to the ECM or PCM, which will cut down the engine’s power if needed. The same will happen if a wheel spin caused by too much throttle is detected. Both these functions, though, are only available in cars equipped with traction control and vehicle stability control.

Where is the U0418 sensor located?

Most cars have the brake control module integrated into the ABS pump assembly. And due to the nature of its job, this component is almost always found inside the engine bay. More precisely, the ABS pump and the brake control module are usually on the driver’s side of the engine bay, near the brake booster.

Other vital components of this system are wheel speed sensors, which, predictably, are integrated into wheel hubs.

What are the common causes of code U0418?

In general, the U0418 trouble code can be caused by anything from a defective brake control module or poor connection to various wiring issues. However, several makes and models are more prone to these issues than others, so this article will focus on them.

Jeep vehicles, in particular, are prone to have the U0418 trouble code. This usually comes in combination with several other communication codes and causes all sorts of warning lights to go off. In some cases, the speedometer will also stop working. Depending on the car, there are several potential causes for this. In some cases, this can be down to damaged or incorrectly routed wiring, which is described in Chrysler’s internal documentation S2108000188 and S2108000074. Another likely possibility is that a CAN-Bus connector under the dash is loose, a problem that’s described in document S2008000062.

Certain 2019-2021 Jeep Cherokee SUVs will suffer from intermittent Brake System warnings, with the U0418 trouble code, among others, being stored in the diagnostic memory. According to several of Chrysler’s service bulletins, this can be solved by reprogramming the Powertrain Control Module (PCM).

Similar to Jeeps, Ford Ranger pickup trucks made from 2011 onwards are also commonly affected by the U0418 trouble code., which usually comes in combination with several other communication codes. This usually happens by occasional interruptions in signal from the wheel speed sensor, which is caused by mechanically damaged wiring. More precisely, the wiring’s insulation becomes brittle and breaks because of constant suspension travel. Vehicles that are frequently driven offroad are more prone to this problem.

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