Vehicle Diagnostics

Vehicle Diagnostics – Engine Fault & Warning Light Diagnosis in Slough

Car Servicing – Interim, Full & Major Car Service

We specialise in accurate and efficient vehicle diagnostics for all makes and models. Whether you’ve noticed a warning light on your dashboard, experienced a sudden drop in performance, or heard unusual noises, our technicians have the expertise and tools to get to the root of the problem quickly.

Our state-of-the-art diagnostic equipment can read and interpret fault codes from your car’s ECU (Engine Control Unit) and identify issues in key systems such as the engine, gearbox, brakes, suspension, and more. We don’t just stop at reading the codes – we investigate the underlying cause so you get the right repair the first time.

Customers across Slough trust Onyx Performance for diagnostics because we combine technical skill with honest advice. We explain faults clearly, recommend only the necessary repairs, and always use high-quality or OEM parts for any work carried out. This means you can get back on the road knowing your car is running smoothly and safely.

Why Choose Onyx Performance?

As Seen on Carwow

We’ve been proudly featured on Carwow – a testament to the quality, professionalism, and performance-focused results that set us apart. Watch our feature here to see us in action.

Expertise You Can Trust

With years of experience and deep technical knowledge, our team understands performance vehicles inside and out – from custom remaps to high-end servicing.

Advanced Workshop & Tools

We operate from a state-of-the-art facility in Slough, equipped with cutting-edge diagnostics, dyno testing, and industry-leading tools for accurate, high-quality work.

Tailored Solutions for Every Vehicle

We don’t believe in one-size-fits-all. Every car gets a bespoke approach, ensuring the best results whether it’s a remap, upgrade, or routine service.

Trusted Nationwide

Performance enthusiasts from across the UK come to Onyx because they know they’ll receive premium-quality workmanship, careful attention to detail, and honest advice.

Complete Care, All in One Place

From tuning and servicing to tyres, trackers, and immobilisers – we offer a full suite of services under one roof, all with a strong focus on safety, reliability, and top-tier customer support.

Customer Reviews

Book Your Vehicle Diagnostics in Slough Today

Don’t ignore that warning light – it could be a sign of something serious. At Onyx Performance, we provide professional vehicle diagnostics in Slough using advanced equipment and expert analysis. Book today and find out exactly what’s going on under the bonnet.

5-Star Google Reviews

0 +

Years of Experience

0 +

Customer Satisfaction

0 %

Why Choose Onyx Performance for Servicing?

Experts in Performance Cars

We know how to properly care for performance, modified, and luxury vehicles. Our team has the skills and experience to handle specialist requirements confidently.

Correct Service Schedules

Every service follows the exact schedule recommended by your vehicle’s manufacturer, helping maintain performance and protect your warranty.

Quality or OEM Parts

We only use high-quality aftermarket or original manufacturer parts, ensuring long-lasting reliability and top-level performance.

Full Vehicle Inspection

Our service goes beyond just changing oil. We inspect all key systems to keep your car safe, smooth, and road-ready.

Honest Advice, No Surprises

With transparent pricing and expert recommendations, you’ll always know what your car needs – no upselling, no hidden fees.

Fast, Trusted & Tracked

We offer quick turnaround, maintain service records, and send reminders – that’s why customers travel to us from across the UK.

Frequently Asked Questions

What does a vehicle diagnostic check involve?

A diagnostic check uses specialist equipment to read your car’s ECU fault codes and assess the health of various systems. At Onyx Performance, we go beyond code reading – our technicians also carry out physical inspections to confirm the exact cause of any issue.

How long does a diagnostic test take?

Most diagnostic checks take between 30 minutes and an hour, depending on the fault. If the problem is more complex, we’ll keep you updated and explain what’s required before carrying out any further work.

Can you diagnose all types of warning lights?

Yes – we can diagnose all dashboard warning lights, including engine management, ABS, airbag, and gearbox lights. Our tools work with all makes and models, including performance and modified vehicles.

What happens after you diagnose the fault?

Once we’ve identified the issue, we’ll explain it in plain English, provide a detailed repair recommendation, and give you a transparent quote. We’ll never proceed without your approval.

Do I really need a diagnostic check if my car still drives fine?

Yes – some faults can cause hidden damage if left unresolved. Even if your car feels normal, a warning light usually means there’s an issue that needs attention before it becomes more serious or costly.

Will a diagnostic check fix the problem?

A diagnostic check identifies the cause but doesn’t fix it directly. However, we can carry out the necessary repairs on-site, using high-quality parts and manufacturer-approved methods to restore your car’s performance.

Get a quick quote

Drop us a line! or Message us on WhatsApp

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.