Inside the ONEFIX workshop at Plas Acton

Diagnostics in Wrexham

Warning light on, odd noise, or it is just not driving right. Our specialist plugs in, drives it if needed, and finds the actual fault instead of guessing at parts.

Diagnostic check
£48.00

Engine Management Diagnostic · inc. VAT. £20 held on your card to book the slot. Nothing is taken unless you do not turn up, and it is released when you do. The diagnostic fee is paid when the work is done, and comes off the repair if you go ahead.

Book a diagnostic
Electrical Fault FindingElectrical Fault FindingQuoted

What the check covers

Full fault-code read across every module, not just the engine
Live data checked while the car runs, and a road test if the fault needs one
The actual cause identified, not just the code the light threw
A written explanation in plain English, with a fixed price to fix it
The diagnostic fee deducted from that price if you go ahead

A code reader tells you where to start looking. It does not tell you what is wrong — that part takes a technician.

Straight with you

Why we will not diagnose over the phone

A knock on left turns could be a CV joint, a drop link, a bearing or a bush. Anyone who names the part before seeing the car is guessing, and you would be the one paying for the guess. We look first, then we tell you exactly what we found.

Common questions

My light has gone off on its own. Still worth checking?
Usually yes — the fault code stays stored even after the light clears, so we can still see what happened.
Will you tell me what is wrong before quoting?
Always. You get the fault and the price together, and you decide from there.
What if you cannot find it?
Some intermittent faults need longer. We will tell you honestly what we know, what we ruled out, and what it would take to go further before you spend another penny.
Do you charge for the check if I go ahead with the repair?
No. The diagnostic fee comes off the repair bill.

Book a diagnostic

Prices correct as at 30 August 2026.

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