AXION AUTOMOTIVE · UK-WIDE POSTAL ENQUIRIES

Automotive Electronics Repair Library

Find repair services by vehicle brand, control-module type or diagnostic symptom. Practical guidance for owners and garages before an assessment.

Prepare a complete repair enquiry: use the vehicle finder and enquiry builder to combine your vehicle, symptoms, previous work and useful guide links into one summary. Review it, copy it or download a text file, then open your email app to contact AXION. Owners, garages and fleet teams can choose the help they need.

New: 100 focused fault guides. Browse EV charging, hybrid heating, ECU and TCU symptoms, body electronics, vehicle networks, programming and diagnostic evidence, organised into ten practical sections.

Another 100 diagnostic guides: explore EV operation, hybrid systems, chassis electronics, ECU memory, gearbox faults, keys and diagnostic reports. Choose a system to find practical next steps.

Search make, model, year & module →

Ask the team →

Illustration of an ECU, circuit board and diagnostic waveform in AXION navy and gold — Control units, circuits and test signals. Illustrative artwork.

SEARCH BY FAULT CODE OR MODULE

Find the code. Understand the next step.

Browse ECU memory faults, voltage and relay codes, CAN communication, DSG pressure, immobiliser and hybrid warnings. Identify Bosch, Continental, Delphi and Denso modules before a repair enquiry.

Open the fault-code directory →

New: EV faults, body networks and module memory

Start with the symptom guides, then explore how controllers communicate and store their software and configuration.

U0110, U0111 and U0112: When an EV Controller Stops Talking

P0AA6 and Charging Refusal: What the Volt and Ampera Bulletin Actually Covers

U0141–U0145: Body-Module Communication and the BCM/BSI Naming Trap

U0146–U0150: Gateway Faults and Why Several Modules Can Disappear Together

CAN Bus Explained: Messages, Termination and the Limits of a 60-Ohm Reading

Inside an ECU: MCU, Flash, RAM and EEPROM in Plain English

Automotive EEPROM Families: Why 24, 25/95 and 93 Devices Are Not Interchangeable

Programming, Coding and Adaptation: What Happens Inside a Vehicle Controller?

More fault codes, grouped by system

Choose a group to see the code guides. Keep the complete scanner description, including any suffix, when asking about a fault.

Sensor supplies and engine circuits

Transmission selectors and lock-up

Body modules and comfort networks

Battery supply and cooling-fan electronics

Dashboard, ABS, key signals and hybrid isolation

Tyre-pressure warnings and sensor learning

ABS sensors, pump supplies and steering setup

ECU and TCU testing, coding and programming

EV and hybrid case reviews and garage referrals

Engine signals, transmission ratios and coolant-pump circuits

EV charging, hybrid start authorisation and advanced diagnostics

Engine temperature, throttle, timing and starting circuits

Transmission temperature, solenoid and clutch-control codes

High-voltage interlocks, converter signals and 48-volt systems

Latest vehicle-electronics guides

Browse the latest practical guides for fault reports, module identification and repair enquiries.

Returning a Repaired Module to a Different Garage
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
A price for assessment and a price for an identified repair describe different work.
Sending a Module with Damaged Connector Pins
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
A no-fault-found bench result describes the tests performed on the removed unit.
Vehicle Works Normally When the Workshop Checks It
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
A scan report showing an incorrect engine, model year or variant should be checked before its conclusions are used.

Browse guides by component

Choose a component or diagnostic topic. These article collections update as new guides are added.

Browse by vehicle manufacturer → · Identify a module →

Engine, sensor and body-electronics fault guides

Choose a system below. Each guide explains the reported fault, the information worth saving and the appropriate assessment route.

Engine and sensor codes: misfire, MAF, EGR, DPF, injectors and more

P0300 and P0301–P0304: Misfire Codes After Plugs or Coils Have Been Replaced

P0335 and P0340: Crankshaft and Camshaft Signal Faults Explained

P0100 and P0101: MAF Air-Mass Sensor Faults Without Guesswork

P0115 and P0118: Coolant Temperature Signal or Actual Overheating?

P0400, P0401 and P0402: EGR Flow Codes and Electrical Diagnosis

DPF Pressure Sensor Warnings: The Sensor, Hoses and Diagnostic Evidence

P2138: Accelerator Pedal Correlation Faults and Reduced Power

P0130 and P0135: Oxygen Sensor Signal and Heater-Circuit Faults

P0201–P0204: Injector Circuit Faults That Return After Replacement

P0299 and P0234: Boost Pressure Warnings and Turbo Actuator Enquiries

Lighting, driver-assistance and 48-volt hybrid systems

Automatic Wipers or Lights Not Working After a Windscreen Replacement

LED Headlight Module Faults: Water Damage, Identification and Coding

Camera and Radar Warnings After Windscreen, Alignment or Accident Repairs

48-Volt Mild-Hybrid Warnings: Battery, Converter and Starter-Generator Identification

EV, battery, fuel-system and new technology guides

Understand the system, record the fault and choose the right assessment. These guides link to manufacturer or component-supplier references and explain what to include in an enquiry.

EV Charging Faults: AC Charging, DC Charging and On-Board Charger Enquiries

Battery Management Systems: BMS, State of Charge and Battery Health Explained

EV Low-Voltage Warnings: The Battery, DC/DC Converter and Vehicle Electronics

Vehicle Software Updates and OTA: What to Record When a Fault Appears

P0087, P0088 and P0191: Fuel Pressure Faults Before an ECU Repair

Zonal Controllers and Vehicle Computers: How Car Electronics Are Changing

Browse by manufacturer or control module

35 vehicle manufacturers and commercial-van enquiries · ECU, TCU, BCM, FRM/SAM and other module routes · Fault codes and ECU families

FIND YOUR NEXT STEP

What needs attention?

Choose the closest description. Each route explains what to prepare and where to start.

01 · Engine ECU or starting fault

Keep the original ECU and record whether the engine cranks, starts briefly or does not respond. Include the complete scan report and photographs of the module label.

ECU repair and cloning →

02 · Gearbox warning or lost drive

Send the gearbox code if known, TCU part number and exact fault codes. Describe which gears are affected and whether the fault changes when warm.

TCU and DSG electronics →

03 · Lights, windows or body electronics

List the functions affected together and any water ingress or battery history. Identify the BCM, BSI, FRM or SAM module before arranging removal.

Body-module assessment →

04 · EV or hybrid system warning

Send the exact dashboard message, vehicle details and a scan report if available. Ask about a complete-vehicle appointment before sending any component. Do not open high-voltage components or send a traction battery.

EV and hybrid diagnostics →

05 · Replacement module or coding problem

Retain both units and photograph both labels. Explain whether the original still communicates and what programming has already been attempted.

Programming and compatibility →

06 · Several warnings or an intermittent fault

Record when the fault happens: cold start, heat, rain or after previous work. A full-vehicle assessment may be needed when several systems are involved.

Complex fault diagnosis →

Already have a unit ready to send? Follow the postal repair checklist. Need the vehicle examined? Choose a workshop assessment.

Start with the information you have

You may know the vehicle brand, the number on the ECU label, or only the warning message on the dashboard. Use the routes below to narrow down the enquiry. A brand name or fault code alone cannot confirm which component needs repair.

Vehicle brands

Prepare the right identification for your make, model and powertrain. Module suppliers and software can differ within one model range.

Browse vehicle brands →

ECU and module types

Engine, transmission, body, restraint and EV controllers have different roles and assessment routes.

Identify your control module →

Fault-code guides

Understand what a scan result does and does not establish before buying a replacement module.

Browse diagnostic guides →

Common reasons customers seek an assessment

No communication

A diagnostic tool cannot reach a controller. The vehicle power supply, network and the module itself may all need investigation.

Read the U0100 / U0101 guide →

Processor fault code

A P0606 entry needs the complete scan report, vehicle details and the manufacturer’s diagnostic process.

Read the P0606 guide →

Failed or interrupted programming

Record what was attempted, which tool was used and whether the original unit still communicates. Keep the original module.

Programming and cloning enquiries →

Build a useful repair enquiry

Record the registration, make, model, year, engine and transmission.
Photograph the complete module label and connectors without opening the unit.
Save a full vehicle scan, including the exact codes, suffixes and reporting controllers.
Describe when the fault occurs and any battery, wiring, water-damage or replacement history.
Ask whether a workshop diagnosis or postal module assessment is appropriate.

Use our full ECU enquiry checklist. If the cause is still uncertain, our postal versus workshop guide explains the difference.

UK-wide module assessment enquiries

Looking for ECU, BCM, SAM or TCU repair support from Birmingham, London, Liverpool, Glasgow or Southampton? AXION welcomes enquiries from owners and garages across the UK. For a suitable removed unit, we can discuss a postal assessment without you travelling to Oxfordshire. Confirm the exact module, symptoms and proposed work before dispatch. Complete-vehicle electrical diagnosis, installation and supported programming may require the vehicle and a separately arranged appointment. Our workshop is in Didcot; the postal enquiry service extends across the UK.