Identify your vehicle and explore ECU, TCU, body electronics, EV and hybrid fault guides. Choose from a broad UK car and van catalogue, then select the system or search a fault code. No registration number needed.
Find a vehicle or module guide
Start with a make to see its model families. Choose a model for recorded year and fuel options, or search a module alone. Use Other / not listed if your vehicle is missing.
123 makes · 1,678 model families · Cars, vans, EVs and hybrids
Choose your make and model, then the system or fault code. Model-specific and make-specific guides appear first, followed by general diagnostic advice. Fuel selection helps describe your enquiry; it does not filter articles or confirm a module is fitted.
About vehicle coverage and years
Vehicle choices are drawn from UK registration records, not from the number of articles. Recorded manufacture years and fuels may be incomplete and are not factory build ranges. Select Other / not listed for a missing vehicle or year. Module choices describe the problem you want help with; availability of assessment and parts must be checked with AXION.
Source: DfT / DVLA vehicle licensing data, 2026 Q2 model and fuel records; 2025 year records. Selected car/van makes and model families with at least 25 licensed vehicles; years/fuels with at least three records. Contains public sector information licensed under the Open Government Licence v3.0. This is a maintained snapshot, not a live registration lookup.
396 guides available
Returning a Repaired Module to a Different Garage
General diagnostic guidance — not vehicle-specific
When one garage removes a unit and another refits it, the diagnostic history can easily become fragmented.
ECU Repair Quote and Diagnostic Assessment: Understand the Scope
General diagnostic guidance — not vehicle-specific
A price for assessment and a price for an identified repair describe different work.
Sending a Module with Damaged Connector Pins
General diagnostic guidance — not vehicle-specific
Bent, missing or corroded pins should be declared before a module is sent for assessment.
Bench Test Says No Fault Found: What the Vehicle Garage Should Check Next
General diagnostic guidance — not vehicle-specific
A no-fault-found bench result describes the tests performed on the removed unit.
Vehicle Works Normally When the Workshop Checks It
General diagnostic guidance — not vehicle-specific
An intermittent fault that does not appear during an appointment is frustrating, but a normal test result still has a defined scope.
Diagnostic Report Uses the Wrong Vehicle Description
General diagnostic guidance — not vehicle-specific
A scan report showing an incorrect engine, model year or variant should be checked before its conclusions are used.
Fault Frequency Counter: Useful Evidence with Important Limits
General diagnostic guidance — not vehicle-specific
Some diagnostic reports include an occurrence or frequency counter.
A Code Clears with Ignition On but Returns When the Engine Starts
General diagnostic guidance — not vehicle-specific
The point at which a code returns can help define the operating condition that triggers it.
A Fault Is Present but No Code Is Stored
General diagnostic guidance — not vehicle-specific
Not every observable problem produces a diagnostic trouble code.
Diagnostic Trouble Code Suffixes: Why the Extra Characters Matter
General diagnostic guidance — not vehicle-specific
A code's extra characters or accompanying failure description can distinguish different conditions within the same broad fault family.
All Keys Lost: What to Prepare for an Authorised Enquiry
General diagnostic guidance — not vehicle-specific
Losing every key requires a vehicle-specific and ownership-verified service route.
Immobiliser Warning Appears After an ECU Was Returned from Repair
General diagnostic guidance — not vehicle-specific
A start-authorisation warning after ECU refitting needs the repair and installation records considered together.
No published guide matches this search. Remove the fault-code filter or ask AXION about your vehicle. A missing article does not mean your unit cannot be assessed.
Reset finder · Browse the full repair library · Browse by brand
How to use the results
Vehicle choices come from UK registration records. A listed model is an identification option, not confirmation of a repair service, stocked part or compatible module. Vehicle-related articles appear first; always compare the documented variant, engine code, gearbox type and module label with your vehicle.
General diagnostic guides remain available alongside vehicle-related results and are clearly labelled. Recorded manufacture years can be incomplete; a missing year does not rule out assessment. Fuel selection is included in your enquiry, but does not establish article coverage or part compatibility. Contact AXION with the exact symptoms and unit details before arranging a repair.
Main electronics and module routes
Engine ECU and sensors · BCM / BSI and body electronics · TCU / DSG and transmission controls · ABS / ESP · Instrument clusters · EV and hybrid systems · Programming and coding · Wiring and electrical diagnosis
Need help identifying the right unit?
Include the make, model, build year, engine or fuel type, transmission, exact fault codes and symptoms. Clear photographs of the module label and connectors help distinguish units fitted to similar vehicles. Please arrange an assessment before removing or posting a component.
Module identification guide · Contact AXION · Book a repair assessment