How much does an engine management diagnostic cost at ONEFIX?
An engine management diagnostic at ONEFIX costs £48.00 inc. VAT. That's quoted in writing before we start, and it's the same figure whichever fault code the car throws up — you're not billed extra part-way through the check.
My engine management light has come on — what does that mean?
It means the engine's management system has logged a fault and wants it looked at; it doesn't tell you on its own how serious that is. See our guide to the engine management light for what to do when it comes on, including when it's safe to keep driving and when it isn't.
Will the diagnostic tell me exactly what's wrong with my car?
It gives us a starting point — the fault codes stored in the system, plus a look at the readings around them — but we don't diagnose your specific car from a description over the phone or before we've had it in front of us. What we can tell you generically is that a code points at an area of the car, not always a single part, which is why the diagnostic itself is a real piece of work rather than a formality.
If it turns out to need a repair, do I pay for the diagnostic on top?
The diagnostic price is what it is regardless of what we find. Any repair that follows is a separate job, quoted to you in writing, and you decide whether to go ahead — we don't carry out work that hasn't been approved.
What if the fault doesn't come back straight away?
Some faults are intermittent, and a diagnostic can only report what the system has actually logged at the time of the check. That's a general feature of how these systems work rather than anything specific to one car, so it isn't something we can promise around in advance.
Do I need to book, or can I just turn up?
Book ahead — a booking is held with a small refundable card hold, released as soon as you turn up. That secures the slot and the diagnostic equipment for your appointment.
Where is ONEFIX, and what are the opening hours?
ONEFIX is at Plas Acton Garage, 282 Chester Road, Wrexham, LL12 8DU. We're open Monday to Friday, 9:00 to 5:00, and closed at weekends.
Book an engine management diagnostic
If a warning light is on, book a diagnostic online and we'll confirm the fixed price in writing before we start.