A warning light on your dashboard can be unsettling. You don't know if it's something minor or something serious — and you just want a straight answer. That's exactly what we give you.
At A Star Garage, we use dealer-level diagnostic equipment to read fault codes, identify problems, and tell you exactly what's going on with your car. No guesswork, no jargon — just a clear explanation and an honest recommendation on what to do next.
We diagnose all makes and models, from Ford Fiestas to BMW 3 Series, hybrids and everything in between.
Diagnostic Services We Offer
Service
What's Involved
Diagnostic scan
Full read of fault codes stored in your vehicle's ECU using dealer-level equipment
Engine management light
Diagnosis and repair of engine-related faults triggering the warning light
ABS warning light
Diagnosis of anti-lock braking system faults — sensors, pump, module
Airbag warning light
Fault code reading and diagnosis of supplemental restraint system issues
Comprehensive scan of all vehicle systems — engine, transmission, ABS, airbags, steering, climate, and more
We don't just read the code and hand you a printout. We interpret what the fault codes actually mean, carry out further testing where needed, and give you a clear plan of action.
How Much Does a Diagnostic Scan Cost?
Diagnostic fault code check: from £50
This covers reading fault codes from your vehicle's ECU and giving you a clear explanation of what's stored. For more in-depth diagnosis — intermittent faults, multiple system scans, or road testing — give us a call and we'll let you know the cost based on what's needed.
You'll always get a clear quote before we start any repair work. The diagnostic fee tells you what's wrong. If you go ahead with the repair, we'll discuss costs separately — no surprises, no pressure.
Common Warning Lights Explained
Not sure what that light on your dashboard means? Here are the most common ones we see:
Engine management light (amber) — The most common warning light. Could be anything from a faulty sensor to a misfire. It needs investigating, but it doesn't always mean something expensive
ABS warning light — Your anti-lock braking system has a fault. Your brakes still work, but ABS won't activate in an emergency. Get it checked soon
Airbag warning light — A fault in the airbag system. Your airbags may not deploy in a crash. This one shouldn't wait
Battery / charging light — Your battery isn't charging properly. Could be the alternator, battery, or wiring. If this comes on while driving, get it looked at quickly
Oil pressure warning (red) — Stop driving. Low oil pressure can cause serious engine damage in minutes
DPF warning light (diesel only) — Your diesel particulate filter is blocked or not regenerating properly. Ignoring this leads to expensive DPF replacement
EPC light (VW/Audi/Skoda) — Electronic Power Control. Often linked to throttle body, brake light switch, or sensor faults. Needs a diagnostic scan to pinpoint the cause
If any warning light comes on, don't panic — but don't ignore it either. Some lights are advisory. Some mean pull over now. If you're unsure, call us on 01273 441044 and we'll advise you.
Why You Shouldn't Ignore Warning Lights
It's tempting to carry on driving when a warning light appears, especially if the car seems fine. But here's the thing:
Small problems become big problems. A faulty sensor that costs £80 to replace can cause a catalytic converter failure that costs £800+
Safety systems may be offline. An ABS or airbag light means those systems won't protect you when you need them most
It's an MOT failure. An engine management light is an automatic MOT fail. So is an ABS or airbag light
It gets more expensive to fix. The longer you leave it, the more likely secondary damage becomes
The diagnostic scan is the cheapest part of the process. It tells you exactly where you stand so you can make an informed decision.
How Long Does a Diagnostic Take?
Service
Typical Time
Basic fault code read
15–30 minutes
Single system diagnosis (engine, ABS, etc.)
30–60 minutes
Full system diagnostics
1–2 hours
Intermittent fault investigation
Up to half day
Most diagnostic scans are done while you wait. If the fault is intermittent or requires road testing, we may need the car for longer — we'll let you know upfront.
Why Choose A Star for Diagnostics?
Dealer-level diagnostic equipment — the same technology main dealers use, without the main dealer prices
We diagnose, then explain — no jargon, no scare tactics
All makes and models — we invest in the tools to diagnose whatever you drive
Honest advice — if it's a minor fault that doesn't need immediate repair, we'll tell you
15+ years experience — fault codes are just the starting point. Experience turns a code into a correct diagnosis
Fix it on-site — most faults we diagnose, we can also repair. One garage, one visit
4.9-star Google rating — our customers trust us because we've earned it
Frequently Asked Questions
A diagnostic scan connects to your car's on-board computer (ECU) and reads any stored fault codes. These codes tell us which system has flagged a problem. We then interpret the codes, run further tests if needed, and give you a clear explanation of what's wrong.
Absolutely. The diagnostic scan is a standalone service. You're under no obligation to have any repairs done with us. We'll give you the information and you decide what to do with it.
Yes. The fault code is still stored in the ECU even if the light has gone off. An intermittent fault is still a fault — and it's usually easier and cheaper to fix before it becomes permanent.
Yes. We have diagnostic equipment for hybrid systems and can investigate warning lights on hybrid and plug-in hybrid vehicles. For fully electric vehicles, give us a call to discuss your specific model.
A basic scan isn't included in a standard MOT, but if we see a warning light during your MOT, we'll let you know it needs investigating. We can run a diagnostic at the same time to save you a second visit.
If you have a warning light on your dashboard, that's the obvious one. But you should also consider a scan if your car is running rough, using more fuel than usual, struggling to start, or just doesn't feel right. The scan can often find problems before they trigger a warning light.
The scan identifies the problem — it doesn't fix it. Think of it like a doctor's examination before treatment. Once we know what's wrong, we'll give you a quote for the repair.
We won't just clear a light without fixing the underlying fault. Clearing a code without a repair means the light will come back — usually within a few miles. The MOT tester will also check for recently cleared codes.