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 one of the most important electronic control systems in a modern vehicle. It continuously processes information from numerous sensors and controls critical engine functions including fuel injection, ignition timing, turbocharger boost, throttle operation, emissions systems, cooling fans, variable valve timing, immobiliser functions and many other vehicle systems.
Modern ECUs perform millions of calculations during vehicle operation. An internal electronic fault can cause poor engine performance, intermittent faults, warning lights, communication problems, starting issues or complete vehicle immobilisation.
At Doyen Auto Services Ltd, we specialise in advanced ECU diagnostics, bench testing, electronic repair, programming and data recovery. Our services can provide a cost-effective alternative where an ECU has been diagnosed as faulty and replacement is being considered.
Symptoms of a Faulty ECU
ECU problems can present themselves in different ways depending on the vehicle, ECU type and nature of the internal fault.
Common symptoms include:
• Engine management warning light • Vehicle will not start or starts intermittently • No communication with diagnostic equipment • Injector driver faults • Ignition coil driver failures • Turbo actuator control faults • Cooling fan running continuously • Limp mode • Misfires with no obvious mechanical cause • Random or unrelated sensor fault codes • CAN Bus communication faults • Immobiliser synchronisation problems • Missing injector pulse • Fuel pump control problems • Throttle body faults • Transmission communication errors • Repeated DPF or AdBlue-related faults • Loss of engine power • Unexplained battery drain • ECU failing to enter sleep mode
Some of these symptoms can be caused by wiring, sensors, power supplies or other vehicle components. Proper testing is therefore important before concluding that the ECU itself is faulty.
Common ECU Failures We Repair
ECUs operate in demanding environments and can be exposed to heat, vibration, moisture, voltage fluctuations and electrical faults.
Common internal ECU failures include:
• Burnt injector driver circuits • Failed ignition output stages • Damaged power supply circuits • MOSFET and power transistor failures • Failed voltage regulators • Internal short circuits • EEPROM corruption • Flash memory corruption • MCU communication faults • Processor-related faults • Water ingress and corrosion 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
Advanced ECU Bench Testing
We use professional ECU bench testing equipment to assess control units outside the vehicle where appropriate.
Our testing can include:
• 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
Bench testing allows us to investigate the ECU independently and helps establish whether an internal ECU fault is present.
Component-Level Electronic Repairs
Where technically possible, we can repair individual electronic components and circuits rather than automatically replacing the complete ECU.
Our electronic repair capabilities can 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 on supported applications • Immobiliser data repair
All repairs are followed by appropriate testing to verify the operation of the ECU before it is returned.
ECU Programming & Data Recovery
Many ECUs contain important vehicle-specific information, including:
• Immobiliser coding • VIN information • Injector coding • Security data • Vehicle configuration • Adaptation values • Calibration information
Where possible, we back up the original ECU data before programming or repair work is carried out.
This can help protect the original data and allow appropriate recovery, cloning or restoration procedures to be carried out when supported by the ECU and vehicle.
Why Repair Instead of Replace?
When an ECU is diagnosed as faulty, replacement is not always the only option.
A replacement ECU may require additional programming, coding, immobiliser synchronisation or configuration before the vehicle can operate correctly.
Repairing the original ECU may offer several advantages:
• Potentially significant cost savings • Retains the original vehicle ECU • Can preserve original coding and vehicle-specific data • Avoids unnecessary replacement of a complete control unit • Useful for discontinued or difficult-to-source ECUs • Can reduce electronic waste • Suitable for many specialist, classic and performance vehicles
The correct solution depends on the ECU, vehicle and nature of the fault. We assess each unit individually before recommending repair or replacement.
Vehicle Applications
We work with ECUs from a wide range of vehicle manufacturers and electronic control system suppliers, including:
• Bosch • Continental • Siemens • Denso • Delphi • Magneti Marelli • Hitachi • Valeo • Visteon • Mitsubishi Electric • Keihin • Temic • And many others
Our experience covers petrol, diesel, hybrid and selected electric vehicle electronic systems.
Why Choose Doyen Auto Services Ltd?
At Doyen Auto Services Ltd, we specialise in automotive electronics, advanced diagnostics and ECU repair using professional diagnostic and electronic testing equipment.
Our approach is based on identifying the underlying fault rather than replacing expensive components without sufficient evidence.
Our services include:
• Advanced ECU diagnostics • Professional ECU bench testing • Component-level electronic repair • EEPROM and Flash programming • ECU cloning and data recovery • ECU programming and coding where supported • Pre- and post-repair testing • Quality-controlled electronic repairs • Technical fault finding • Cost-effective alternatives to ECU replacement
Whether your vehicle has a no-start condition, communication fault, intermittent electrical problem, ECU-related warning light or suspected control unit failure, Doyen Auto Services can assess the ECU and provide professional diagnostic and repair advice.
Doyen Auto Services Ltd Unit 8, Levenside Business Court Dumbarton G82 3PE
Telephone: 0141 467 2904 Mobile: 07760 926245
