A weak or failing 12-volt battery or poor charging system voltage causing the chassis control module to transmit corrupted data; Corroded, loose, or damaged connectors and terminals at Chassis Control Module A or at the module that stores the code; Wiring damage in the controller area network (CAN) bus or other communication circuits between the chassis module and the receiving module; A software or calibration fault in Chassis Control Module A that causes it to broadcast out-of-range values; A failing Chassis Control Module A that intermittently drops off the network or sends invalid frames; A faulty wheel speed sensor, steering angle sensor, or yaw rate sensor feeding bad data into Chassis Control Module A; A problem with the receiving module itself, such as an internal communication fault, that makes it reject valid data

DTC codes / U04xx · Invalid data received from a module / U042B

U042BInvalid Data Received From Chassis Control Module A

Q: What does code U042B mean?

Invalid Data Received From Chassis Control Module A. U042B means the module that coordinates the vehicle's main network received data from Chassis Control Module A that it judged invalid or out of range. The receiving module did not lose contact with the chassis module; it got a message it could not trust, so it set this communication code and may disable features that depend on that data.

U042B means the module that coordinates the vehicle's main network received data from Chassis Control Module A that it judged invalid or out of range. The receiving module did not lose contact with the chassis module; it got a message it could not trust, so it set this communication code and may disable features that depend on that data.

SystemNetwork

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyProfessional

AreaInvalid data received from a module

Symptoms you may notice

Illumination of the anti-lock brake (ABS), traction control, or stability control warning light
A message on the driver information display stating that a chassis or stability system is unavailable
Reduced or disabled stability control, traction control, or hill-descent features
An unexpected steering feel or warning if the chassis module shares steering angle data
Often no symptoms besides the warning light, with the vehicle driving normally
Multiple unrelated warning lights if the invalid data affects several modules on the network

Common causes, most likely first

A weak or failing 12-volt battery or poor charging system voltage causing the chassis control module to transmit corrupted data
Corroded, loose, or damaged connectors and terminals at Chassis Control Module A or at the module that stores the code
Wiring damage in the controller area network (CAN) bus or other communication circuits between the chassis module and the receiving module
A software or calibration fault in Chassis Control Module A that causes it to broadcast out-of-range values
A failing Chassis Control Module A that intermittently drops off the network or sends invalid frames
A faulty wheel speed sensor, steering angle sensor, or yaw rate sensor feeding bad data into Chassis Control Module A
A problem with the receiving module itself, such as an internal communication fault, that makes it reject valid data

How to diagnose and fix it

Perform a full scan of all modules and record every stored, pending, and history code before clearing anything
Test the battery and charging system, including a load test and voltage-drop checks, because low voltage corrupts network messages
Inspect and clean the connectors and terminals at Chassis Control Module A and at the module that set U042B, looking for corrosion, water intrusion, or loose pins
Check the communication bus wiring for continuity, shorts to ground or power, and correct termination resistance
Verify that Chassis Control Module A has the latest known-good software or calibration and reprogram it if an update applies
Check live data from the wheel speed, steering angle, and yaw rate sensors that feed the chassis module for implausible or intermittent values
If wiring, power, and sensor inputs are correct, substitute a known-good Chassis Control Module A or the receiving module to isolate the faulty unit

Why U042B is often a voltage or wiring fault

A weak battery is one of the most common root causes of U042B because chassis control modules can transmit corrupted frames when supply voltage sags during cranking or under load.
Technicians who replace Chassis Control Module A first often find the code returns because the real problem is a corroded connector or a chafed CAN bus wire that intermittently shorts.
U042B does not mean the chassis module is dead or offline; it means the receiving module received a message it considered invalid, which can come from a sensor feeding bad data into the chassis module.
A wheel speed sensor or steering angle sensor with an intermittent signal can cause the chassis module to broadcast implausible values without setting its own sensor code, so live data review is essential.
After repairs, the code may need to be cleared and a relearn or calibration drive cycle performed before stability control features return to normal.

Can I keep driving with U042B?

The vehicle is usually safe to drive to a repair shop because the fault mainly affects stability and traction features, but avoid aggressive driving, towing, or slippery conditions until it is diagnosed. If the warning lights are accompanied by reduced power steering assist or brake warning lamps, stop driving and have the vehicle towed.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.