Car Key, Remapping & DPF Advice
Practical answers to the questions people actually ask before calling — what a fault means, what it is likely to cost you in effort, and what you can reasonably check yourself first. Written to be useful whether or not you end up needing us.
Start here
The guides below are grouped by what has actually gone wrong. If you are not sure which section you need, the quickest route is usually the symptom: a key that will not turn is a different problem from a key the car does not recognise, and they are in different places.
Lost keys and lockouts
Key faults and repairs
Fob dead after a battery change
Usually not the programming. Three things to check.
Key programming and cloning
Vehicle security
Protecting a keyless car
How relay theft works, and what genuinely reduces the risk.
What it costs, and why
By vehicle make
Remapping
Does remapping improve MPG?
An honest answer, including why it often does not.
What affects remapping cost
And why the cheapest quote is often a different job.
DPF and emissions
Can you drive with a blocked DPF?
When a motorway run helps, and when it does not.
AdBlue
Diagnostics and fault codes
How mobile diagnostics works
What suits a driveway, and what needs a ramp.
Popular questions
The questions that come up most often on the phone, answered in full in the guides above.
- Can a locksmith make a key if I have lost every one? Usually yes, at the vehicle — see the all-keys-lost guide.
- Will a new key stop my existing keys working? On most vehicles no, but some systems re-learn every key together.
- My car will not start but the dash lights up. Is it the key? Often not — the immobiliser guide covers the four causes.
- Is a remap safe, and do I have to tell my insurer? Yes to the declaration, always. The remapping guides cover the rest.
- My DPF light is on. Can it be cleaned? It depends on soot versus ash, which is measured rather than guessed.
Where these guides lead
Each guide links to the service page that covers the work itself. If you would rather start from the service, these are the main ones.
Car keys and locksmith work
Replacement, spares, all keys lost, programming and lockouts.
Question not covered?
Send the registration and describe what the vehicle is doing. You will get a straight answer whether or not it turns into a job.