How Much Does Car Diagnostics Cost?
The short answer
Diagnostics costs £20 with SV Autos, plus the £20 call-out, and the full £40 comes off the bill if you have us do the repair. We come to your home or work, read the fault properly, and tell you in plain English what the car is actually doing.
The awkward thing about diagnostics is that you're paying to find out what is wrong, before you know whether it's worth fixing. That's why ours comes off the repair. If we do the work, the diagnostic has effectively cost you nothing, and if you decide not to go ahead you still get a straight answer and a written price.
What it costs
| Job | Labour | What that covers |
|---|---|---|
| Diagnostics | £20 | We plug in, read the fault codes, interpret them against what the car is actually doing, and explain what it means. |
| Call-out | £20 | Coming to your home or work. The two together are the £40 that comes off the repair. |
| The repair itself | Quote | Priced once we know what is wrong, and agreed with you in writing before anything starts. The £40 comes off it. |
| Pre-MOT check | £20 | A different job worth knowing about: we check the common MOT fail points before the test, rather than reading fault codes. |
| 30-point health check | £80 | For when nothing specific is wrong but you want to know where the car stands. 10 areas scored out of 3. |
The whole £40, both the diagnostic and the call-out, comes off the price of the repair if you have us do it.
How our pricing works
Labour
The prices above. Fixed for the job, not charged by the hour, so a job running long is our problem rather than yours.
£20 call-out
One flat fee to come to you, anywhere in our area. No mileage charges and no surcharge for being further out.
Parts
Quoted for your exact car. They vary too much between makes and models to publish honestly, so we price them properly rather than guessing.
You get the three added together, in writing, before any work starts. If the job changes once we are looking at the car, you hear it from us first.
What changes the price
Any price that starts with "from" needs explaining, or it is just a hook. Here is what actually moves the number for your car.
- Is the fault there when we arrive
- A light that's on now is far easier than one that comes and goes. Intermittent faults sometimes need the car driven or left to reproduce the conditions, and we'll tell you if that's where we're.
- How many faults are stored
- Cars often store several codes, some of them historic and irrelevant. Reading them is quick; working out which one actually matters is the part that takes experience.
- What the code actually means
- A code names a circuit, not a broken part. An oxygen sensor code can be the sensor, or the wiring, or an air leak upstream making the sensor read oddly. Replacing the named part without checking is how people spend money twice.
- What we cannot do
- We don't take on wiring faults or automatic gearbox work, so if the diagnostic points there we'll say so and point you to someone who does, rather than start a job we should not.
Your questions
Is a car diagnostic worth paying for?
It's when the alternative is guessing. A code reader tells you a circuit has reported a fault; it doesn't tell you which part failed or why. Paying someone to interpret it's usually cheaper than replacing the wrong part first. With us the fee comes off the repair anyway, so if the answer is something we then fix, the diagnostic costs you nothing extra.
Can I do a car diagnostic myself?
You can read the codes yourself. A basic reader isn't expensive and will tell you what has been logged, which is genuinely useful. What it won't do is tell you whether the sensor is faulty or is simply reporting a real problem elsewhere. If the code points at something simple you may well fix it yourself, and we'd sooner tell you that than take your money.
Does the engine light always mean something expensive?
No. It can be a loose fuel cap, a sensor on its way out, or something that matters a great deal. The light itself doesn't distinguish, which is the whole problem with it. A steady light generally means get it looked at soon; a flashing one means stop driving, because that usually indicates a misfire that can wreck the catalytic converter.
Will you tell me if it's not worth fixing?
Yes. If the repair costs more than the car is worth, or the fault points at something we don't take on, you'll hear that. It's a short conversation that saves you money and we'd rather have it than sell you a job.
How long does a diagnostic take?
Usually under an hour for a fault that's present and behaving. Intermittent problems can take longer, and occasionally need a second look. We tell you where we've got to rather than running up time quietly.
Do you come out just for a diagnostic?
Yes. Plenty of people book a diagnostic on its own to find out what they're dealing with before deciding anything. You aren't committing to the repair by asking.
Prices on this page are labour from £20, plus the £20 call-out and parts. Confirmed with James and current at the time of writing.
Tell us what your car's doing
A clear price agreed before anything is booked. No obligation, no pressure.
We reply within 48 hours, and if it's urgent it's quicker to ring or send a WhatsApp. There's a flat £20 call-out and then a clear price for the work, agreed before anything starts. Nothing to pay up front, no cancellation fee, and you settle up once the work is done, by card, cash or bank transfer.