Diagnostics

Car Warning Light Or Fault?

Tell us what the car is doing. We will help you choose the right next step.
Llandow workshop, South Wales customers

Start with the symptom, not the workshop term

Most owners arrive because the engine light is on, the car has lost power, the gearbox is jerking, the DPF warning will not clear, the AdBlue countdown has started or the car will not start.

Choose the page that sounds most like the fault you are seeing. If you are not sure, use the free first check and we will point the enquiry toward servicing, repair work or proper fault-finding.

Engine light, limp mode or poor running

Start here if this sounds closest to what the car is doing. It explains the likely route, what information helps and when a repair or service is the better booking.

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Car misfiring or shaking under load

Start here if this sounds closest to what the car is doing. It explains the likely route, what information helps and when a repair or service is the better booking.

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Check engine light on

Start here if this sounds closest to what the car is doing. It explains the likely route, what information helps and when a repair or service is the better booking.

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DPF warning or blocked filter

Start here if this sounds closest to what the car is doing. It explains the likely route, what information helps and when a repair or service is the better booking.

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EGR fault, smoke or hesitation

Start here if this sounds closest to what the car is doing. It explains the likely route, what information helps and when a repair or service is the better booking.

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AdBlue countdown or no-start warning

Start here if this sounds closest to what the car is doing. It explains the likely route, what information helps and when a repair or service is the better booking.

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Gearbox problem or warning message

Start here if this sounds closest to what the car is doing. It explains the likely route, what information helps and when a repair or service is the better booking.

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Car shaking, brake judder or vibration

Start here if this sounds closest to what the car is doing. It explains the likely route, what information helps and when a repair or service is the better booking.

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Car losing power

Start here if this sounds closest to what the car is doing. It explains the likely route, what information helps and when a repair or service is the better booking.

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Car will not start

Start here if this sounds closest to what the car is doing. It explains the likely route, what information helps and when a repair or service is the better booking.

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Electrical fault or battery warning

Start here if this sounds closest to what the car is doing. It explains the likely route, what information helps and when a repair or service is the better booking.

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Fault nobody has fixed yet

Start here if this sounds closest to what the car is doing. It explains the likely route, what information helps and when a repair or service is the better booking.

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Find the right booking

Start with the symptom

Warning lights

Engine light, EPC, DPF, AdBlue or gearbox warning

A dashboard warning does not always mean the part named in the code is faulty. It means the car has seen something outside its expected range. We start with the message, the symptoms and the stored information, then decide what should be tested.

  • Engine management light, EPC light, glow plug light or emissions warning.
  • DPF blocked, regeneration failed, AdBlue countdown or no-start warning.
  • Gearbox malfunction, PRNDS flashing, transmission fault or limp mode.
  • ABS, battery, charging, start-stop or electrical warning lights.
How it drives

Limp mode, hesitation, misfire, smoke, vibration or no power

If the car drives differently, the detail matters. A fault that happens cold, hot, under load, at motorway speed or in traffic can point to a different cause. Tell us exactly when it happens and what has already been tried.

  • Losing power uphill, under boost or when overtaking.
  • Misfire at idle, under load, when cold or after rain.
  • Smoke, rough running, poor fuel economy or cutting out.
  • Vibration through the wheel, seat, pedals or body of the car.
Service or repair?

A service will not cure every warning light

A routine service is maintenance. It is not the same as fault-finding. If the car already has a warning light, misfire, gearbox complaint or emissions countdown, we will tell you whether servicing is sensible or whether the fault needs to be understood first.

  • Useful when you are not sure whether to book servicing, repair or diagnosis.
  • Helps avoid paying for a service when the car actually needs fault-finding.
  • Helps avoid replacing parts just because a code mentions them.
Read about the free first check
What to tell us

The more specific the symptom, the faster we can route it

When you enquire, send the registration, mileage, warning message, when the fault happens, any recent work and any code printout or dashboard photo you have. That gives us a better starting point than a one-line message saying the car needs plugging in.

  • Registration, mileage, engine/gearbox if known and service history if relevant.
  • Exact dashboard wording or a photo of the warning message.
  • When it happens: cold, hot, idle, traffic, motorway, towing or under load.
  • Any parts already fitted, codes already read or advice already given elsewhere.
Send an enquiry
Diagnostics

Find the closest problem

You do not need to know the workshop term. Tell us the symptoms and we will explain whether the car needs servicing, fault-finding or repair work.

Common reasons people contact us

  • Engine light, EPC light, glow plug light, limp mode or a warning message on the dash.
  • Car misfiring, shaking, hesitating, smoking, cutting out or using too much fuel.
  • DPF, EGR or AdBlue warnings, countdown messages or repeated emissions faults.
  • Gearbox jerking, slipping, banging into gear, warning messages or no drive.
  • Vibration, brake judder, steering wheel shake, starting problems or electrical faults.
  • Not sure what to book? Start with the free first check and tell us the symptoms.
If the problem points elsewhere

Other useful routes

Not sure? Start here

This is often the better route when the symptoms, service history or inspection point in a different direction.

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Repairs after diagnosis

This is often the better route when the symptoms, service history or inspection point in a different direction.

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Send us the symptoms

This is often the better route when the symptoms, service history or inspection point in a different direction.

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Not Sure What Is Wrong?

Tell us the symptoms and we will point you in the right direction.

If you are unsure whether the car needs servicing, fault-finding or repair work, start with the free first check.