Mon – Fri 9:30am – 5:30pm · Sat 10am – 3pm
Don't replace what can be repaired. We diagnose and fix faulty engine control units at a fraction of the cost of a new unit.
From
£150
Final quote will be confirmed after vehicle registration and assessment
Estimated 3 hrs
Prices shown are starting prices. Final cost depends on your vehicle's make, model, and condition. We always provide a free estimate before starting work.
ECU Testing, Diagnostics & Electronic Repair
Professional Engine Control Unit (ECU) Testing & Repair
The Engine Control Unit (ECU) is the primary computer responsible for controlling your vehicle's engine management system. It continuously processes information from dozens of sensors throughout the vehicle and precisely controls fuel injection, ignition timing, turbocharger boost pressure, throttle operation, emissions systems, cooling fans, variable valve timing, immobiliser functions and many other critical engine operations.
Modern ECUs perform millions of calculations every minute. Even a minor internal fault can result in poor engine performance, intermittent faults, warning lights or complete vehicle immobilisation.
At Doyen Auto Services Ltd, we specialise in advanced ECU diagnostics, bench testing, component-level electronic repairs and ECU programming, providing a cost-effective alternative to expensive dealer replacement units.
Symptoms of a Faulty ECU
An ECU failure can present itself in many different ways depending on the vehicle manufacturer and the type of internal fault.
Common symptoms include:
* Engine Management Light permanently illuminated * Vehicle will not start or intermittent starting * No communication with diagnostic equipment * Injector driver faults * Ignition coil driver failures * Turbo actuator control faults * Cooling fan operating continuously * Limp mode * Misfires with no mechanical cause * Random sensor fault codes * CAN Bus communication faults * Immobiliser synchronisation issues * Injector pulse missing * Fuel pump not operating * Throttle body faults * Transmission communication errors * Repeated DPF or AdBlue related faults * Loss of power * Unexplained battery drain * ECU not entering sleep mode
Many of these symptoms are often misdiagnosed, resulting in unnecessary replacement of sensors, wiring or other expensive components when the ECU itself is the root cause.
Common ECU Failures We Repair
Electronic control units operate in harsh environments where they are subjected to vibration, heat, moisture and voltage fluctuations.
Common ECU faults include:
* Burnt injector driver circuits * Failed ignition output stages * Blown power supply circuits * Damaged MOSFETs and power transistors * Burnt voltage regulators * Internal short circuits * EEPROM corruption * Flash memory corruption * MCU communication faults * Processor failures * Water ingress damage * Corroded PCB tracks * Broken solder joints * Lifted PCB pads * CAN Bus transceiver failures * LIN Bus communication faults * Sensor reference voltage failures * Reverse polarity damage * Voltage spike damage * Overheating damage * Software corruption * Bootloader corruption
Case-by-case pricing. The figures below are starting “from” prices - your final quote depends on your vehicle's make, model, and condition.
ECU Diagnostic Check
ECU Repair
ECU Replacement & Programming
We always provide a free, no-obligation quote before any work begins. Call 07760 926245 or WhatsApp 07760 926245.
Here’s what to expect when you bring your vehicle to Doyen Auto Services
We carry out a thorough diagnostic to confirm the ECU is the root cause and identify the specific fault within the unit.
The ECU is carefully removed and opened up for a detailed inspection of the circuit board and components.
Faulty components are replaced, damaged circuits are repaired, and the software is reprogrammed as needed.
The repaired ECU is refitted, coded to the vehicle, and thoroughly tested to confirm full operation.
We’re a specialist automotive garage in Dumbarton, with the equipment, experience, and honest approach to get the job done right first time.
Specialist ECU diagnostic equipment that goes beyond standard fault code readers
Experience repairing ECUs across a wide range of makes and models
Honest assessment - if a repair isn't viable, we'll tell you straight away
Conveniently located in Dumbarton for customers across Glasgow and South Lanarkshire
Common questions about this service at Doyen Auto Services
Starting from
£50
Don't ignore that warning light. We'll find out exactly what's wrong and get it sorted - properly.
Learn moreStarting from
£50
Specialist electrical fault finding for complex wiring, sensor, and module issues that other garages can't solve.
Learn moreStarting from
£75
A comprehensive scan of every module in your vehicle. Find out exactly what's going on - not just the engine, but every electronic system.
Learn moreStarting from
£150
Transfer all data from a faulty ECU to a replacement unit - no dealer visit required. Get your vehicle back on the road quickly.
Get in touch today to book your ecu repair at our Dumbarton workshop. Online booking or call us directly.
Unit 8, Levenside Business Court, Dumbarton G82 3PE · Mon–Fri 9:30am–5:30pm, Sat 10am–3pm
These failures often develop gradually before eventually causing complete ECU failure.
Advanced ECU Bench Testing
Unlike many repair workshops that simply replace parts, we use professional bench testing equipment to fully evaluate the ECU before any repair is undertaken.
Our laboratory testing includes:
* Complete ECU bench simulation * Communication verification * Power supply testing * Current consumption analysis * CAN Bus communication testing * LIN Bus testing * Oscilloscope signal analysis * Input and output circuit testing * Sensor simulation * Actuator simulation * Injector driver testing * Ignition driver testing * Relay output testing * EEPROM verification * Flash memory integrity checks * Microprocessor communication testing
This allows us to accurately identify component-level failures before repairs begin.
Component-Level Electronic Repairs
Our ECU laboratory is equipped to carry out precision electronic repairs rather than replacing complete control units.
Our capabilities include:
* SMD component replacement * BGA rework * MOSFET replacement * Driver IC replacement * Voltage regulator replacement * Capacitor replacement * PCB track reconstruction * Corrosion removal * Micro soldering * EEPROM programming * Flash memory programming * MCU programming (where supported) * Data recovery * Software restoration * Boot mode recovery * ECU cloning * ECU virginisation (supported applications) * Immobiliser data repair
Every repair is performed using professional equipment with comprehensive quality control procedures.
ECU Programming & Data Recovery
Many ECUs contain valuable vehicle-specific information including:
* Immobiliser coding * VIN information * Injector coding * Security data * Configuration data * Adaptation values * Calibration files
Before carrying out any programming or repair, we create a complete backup of the original ECU memory wherever possible.
This allows us to safely recover software, restore original data or return the ECU to its previous state if required.
Why Repair Instead of Replace?
A main dealer will often recommend replacing the entire ECU, even when the fault is caused by a single failed electronic component.
Replacement costs can range from £500 to well over £2,500, with additional charges for programming, coding and installation.
Professional ECU repair offers many advantages:
* Significant cost savings * Retains the original factory ECU * Preserves immobiliser and coding data * Faster turnaround * Environmentally responsible by reducing electronic waste * Ideal for discontinued or hard-to-source ECUs * Suitable for classic, performance and specialist vehicles
In many cases, repairing the original ECU is both the most economical and technically appropriate solution.
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Vehicle Applications
We repair engine control units fitted to a wide range of manufacturers including petrol, diesel, hybrid and selected electric vehicles.
Our experience covers:
* Bosch * Continental * Siemens * Denso * Delphi * Magneti Marelli * Hitachi * Valeo * Visteon * Mitsubishi Electric * Keihin * Temic and many others.
Why Choose Doyen Auto Services Ltd?
At Doyen Auto Services Ltd, we specialise in advanced automotive electronics and ECU repair using professional laboratory equipment and dealer-level diagnostic systems.
Our commitment to precision diagnostics means we identify the root cause of ECU failures rather than simply replacing expensive components unnecessarily.
We provide:
* Advanced ECU diagnostics * Professional bench testing * Component-level electronic repair * EEPROM & Flash programming * ECU cloning and data recovery * Quality-controlled repairs * Comprehensive pre- and post-repair testing * Honest technical advice * Cost-effective alternatives to ECU replacement
Whether your vehicle suffers from a no-start condition, communication fault, intermittent electrical issue or complete ECU failure, our specialist technicians have the equipment and expertise to diagnose and repair your ECU to the highest professional standard.
