At Ross Auto-Electrical Ltd, we specialise in diagnosing and repairing complex electrical and electronic faults across all makes and models. Our expertise lies in solving problems that other garages are unable to identify, using a structured diagnostic process supported by manufacturer-level equipment, specialist test equipment and years of experience.

From intermittent electrical faults and communication failures to immobiliser issues and advanced ECU diagnostics, we focus on identifying the root cause of a fault—not replacing parts by guesswork.

We regularly diagnose and repair:

• Auto-electrical faults
• CAN Bus and vehicle network communication faults
• ECU and control module failures
• Immobiliser and non-start issues
• Parasitic battery drains
• Wiring harness and electrical repair
• Water ingress and corrosion-related electrical faults
• Intermittent electrical faults
• Advanced vehicle diagnostics
• ECU programming, coding and configuration
• Manufacturer-specific electrical faults

Ross Auto-Electrical Ltd is an independent Mercedes-Benz electrical diagnostic specialist, providing advanced fault finding and repair for modern Mercedes-Benz vehicles without the main dealer price tag.

We have extensive manufacturer experience diagnosing faults involving:

• Front and Rear SAM Control Modules
• EZS (Electronic Ignition Switch)
• ESL (Electronic Steering Lock)
• Engine & Transmission Control Units
• Body Control Modules
• CAN Bus communication faults
• Battery management systems
• Water ingress and corrosion damage
• Electrical wiring and network faults
• Vehicle programming and coding

Using specialist diagnostic equipment and manufacturer-level technical information, we provide dealership-level diagnostic capability with the personalised service of an independent specialist.

£80 per hour

A structured diagnostic investigation including:

• Global system scan
• Fault code analysis
• Live data assessment
• Wiring diagram interpretation
• System function testing
• Diagnostic planning

This stage establishes the direction of the investigation and identifies the most effective route towards repair.

£110 per hour

Where additional electrical testing is required, our investigation may include:

• Circuit integrity testing
• Voltage drop analysis
• Oscilloscope testing
• Signal tracing
• CAN Bus diagnostics
• Parasitic battery drain investigation
• Network communication analysis
• Advanced wiring fault diagnosis

This level of investigation is designed for complex faults requiring specialist testing beyond routine diagnostics.

£100 per hour

Specialist labour applicable to complex Mercedes-Benz electrical diagnosis, programming and repair.

Typical work includes:

• SAM module diagnostics
• Vehicle programming and coding
• Immobiliser diagnostics
• Network communication faults
• Control module configuration
• Electrical fault tracing
• Manufacturer-specific diagnostic procedures

From £450

Where initial investigations indicate a complex electronic system fault, we offer comprehensive diagnostic investigations covering:

• ECU integrity testing
• Control module evaluation
• Vehicle network analysis
• CAN communication testing
• Module input and output verification
• Programming assessment
• System architecture diagnosis

This service is intended for vehicles with complex electronic faults requiring significant investigation.

£350–£650

(Vehicle dependent)

Where repair is viable, we can arrange professional ECU bench testing and internal electronic repair, offering a cost-effective alternative to replacement where appropriate.

Unlike traditional garages, we don't rely on trial-and-error or unnecessary parts replacement.

Our diagnostic process is based on evidence, technical testing and manufacturer procedures, ensuring faults are accurately identified before repairs are recommended.

Our commitment is to provide:

• Accurate, evidence-based diagnostics
• Transparent pricing
• Clear communication throughout the investigation
• No speculative parts replacement
• Honest recommendations
• Manufacturer-level diagnostic capability
• Specialist electrical expertise

Many of the vehicles we diagnose have already undergone unsuccessful repair attempts elsewhere. Our goal is to identify the root cause of the problem and provide the most appropriate repair solution, saving customers both time and unnecessary expense.

If you're experiencing an electrical fault that nobody else has been able to resolve, we'd be happy to discuss your vehicle and recommend the most appropriate diagnostic investigation.