Diagnostics
Dashboard light on? We’ll find out why
Engine not quite right? Our diagnostics pinpoint the problem fast, saving you time and money on guesswork repairs.
From warning lights to weird noises, we read the fault codes, test the parts they point to and tell you what we’ve found before anything gets replaced.
Not sure how urgent it is? Our warning light guide covers the common ones, and you can always ring us.
- Fault code readingEngine, ABS, airbag, DPF and more.
- Proper testingWe confirm the fault before replacing parts.
- Plain EnglishWhat’s wrong, how urgent it is and what it costs.
- Cars and vansAll makes and models.
What a diagnostic actually is
Plugging in a code reader is the start, not the answer. A fault code names a circuit or a reading that is out of range — it does not name the broken part. A code pointing at an oxygen sensor can just as easily be a wiring fault, an air leak or a failing sensor somewhere else in the chain.
That is why we test what the code points to before replacing anything. Fitting the part named on the screen is how people end up paying twice for the same fault.
What we can read
Engine management, ABS and traction control, airbag and restraint systems, diesel particulate filters, and the body and comfort systems that throw up their own warnings. We can also read stored and pending codes and live sensor data, which is often what catches an intermittent fault.
Intermittent faults
The awkward ones are the faults that come and go. A light that has cleared itself may still have left a stored code, so it is worth having it read rather than hoping. If the fault is genuinely intermittent, the live data and freeze-frame recorded when it last happened are usually what pins it down.
Common warning lights
Diagnostics: common questions
My engine light is on. Can I keep driving?
A steady light generally means get it checked soon. A flashing engine light means stop as soon as it is safe to — it usually indicates a misfire that can damage the catalytic converter. If you are not sure, ring us and describe it.
The light went off by itself. Is it fixed?
Not necessarily. Many systems clear the light after a number of clean journeys but keep the code stored. Having it read tells you whether something is still brewing.
Can you tell me what is wrong over the phone?
We can usually tell you how urgent it sounds and what it might be, but not what it is. The code and the tests are what turn a guess into an answer.
Do you charge for diagnostics if I have the repair done?
Ring us and ask — we will tell you where you stand before you book, so there are no surprises either way.
What do the dashboard symbols mean?
Our warning light guide covers the common ones and what to do about each. Red generally means stop; amber generally means get it looked at.
Ready when you are