Fault-code directory · Vehicle network diagnostics
Several brake, steering or stability warnings can appear together because these systems share information. That does not establish that several control units have failed. Safety-related symptoms must still be taken seriously, especially if braking or steering behaviour changes.
Codes covered
U0415 · U0416 · U0417 · U0418 · U0420 · U0428
This selection concerns data from ABS, vehicle-dynamics, parking-brake, brake-control, steering-control and steering-angle systems. The exact source is identified by the full code description. Invalid data is a different finding from a missing controller or a confirmed mechanical brake fault.
Confirm the full description, suffix and reporting module for your vehicle. These are diagnostic starting points, not a parts replacement list.
Evidence that helps narrow the fault
- Follow the vehicle’s warning and recovery instructions. Record the warning sequence without performing a road test that feels unsafe.
- Obtain a whole-vehicle scan and identify primary faults in the source system. A wheel-speed, steering-angle or supply concern may explain secondary reports elsewhere.
- Review recent wheel, brake, steering, alignment and module work. Calibration is relevant only when the required mechanical and electrical prerequisites are satisfied.
Choosing the next repair step
The assessment should explain which system first produces unreliable information and why. A successful calibration does not prove that an intermittent wiring fault has disappeared, and clearing the warning does not verify braking performance. Final checks must cover the relevant safety function as well as the stored codes.
Can the ABS module be sent by post before the vehicle is checked?
Contact AXION first. Some electronic faults can be assessed on a removed unit, but sensor, hydraulic, installation and vehicle-network faults may require the complete vehicle.
Talk through the fault with AXION
Send the make, model, year, full scan report and a short description of when the fault happens. Include recent repairs or programming attempts. If you do not have a scan, describe the symptoms in your own words.
Workshop assessments are arranged by appointment in Didcot, Oxfordshire. UK-wide postal module testing and remote support are available for suitable work after compatibility and scope are agreed. Please contact us before removing or posting a module.
Assessment options and appointments · Garage and trade support
Related reading
Reference for generic code terminology: Snap-on diagnostic code reference. Use the manufacturer’s current service information for the actual vehicle and test procedure. This article provides general diagnostic guidance and is not a report of a particular customer repair.