Vehicle
Diagnostics

What Vehicle Diagnostics Actually Involves

A plug-in code reader will tell you which system has logged an issue. It won't tell you what caused it, whether the part has actually failed, or whether the fault is electronic, mechanical or both. A fault code is a starting point — not an answer.

Our diagnostic service is our most requested — and the most misunderstood. It is far more than a system scan. It is a proper, methodical investigation carried out by an experienced technician using professional equipment.

A standard diagnostic session (up to one hour) typically includes:

• Full system scan — reading fault codes and event logs from all control modules
• Live data analysis — monitoring sensor values and system parameters while the vehicle is operating
• Wiring and circuit testing — checking signal quality, continuity, shorts and resistances using oscilloscopes and meters
• Communications testing — verifying CAN bus and network signals between control units
• Component testing — confirming whether a component has actually failed before recommending replacement
• Clear written findings — a full explanation of what was found, what was confirmed through testing, and what we recommend

We do not replace parts based on fault codes alone. We test to confirm. This is the difference between a proper diagnosis and an expensive guess.

Extended Diagnostics

Some faults require more time to investigate properly. Intermittent issues that only appear under specific conditions, complex multi-system faults, and larger or more complex vehicles — such as Range Rovers, large commercials or specialist vehicles — often need extended sessions of up to two hours.

We will tell you upfront if we believe a standard session is unlikely to be sufficient. Extended diagnostics is charged at £216 including VAT (£180 + VAT) and is always agreed with you before any additional time is used.

When Diagnostics Is the Right Starting Point

Diagnostics is typically needed when warning lights or fault messages are present, the engine is running poorly, misfiring or in limp mode, there are electrical or intermittent faults, starting or charging problems have developed, or previous repairs elsewhere have not resolved the problem.

Sometimes the root cause is electronic. Sometimes it is mechanical. Often it is both. Our job is to find where it begins — not guess what it might be.

Specialist Equipment

• Autel MaxiSys — full system scanning, ECU coding and programming
• Launch — wide multi-brand diagnostic coverage
• Pico oscilloscope — electrical signal testing, waveform capture and analysis
• Manufacturer system access — JLR, VW/Audi, Peugeot/Citroën, Fiat and more

Manufacturer System Access

Certain diagnostic and programming procedures require direct access to manufacturer systems. Where this applies, there may be a small additional access charge — we will always explain this in advance and only apply it when genuinely needed. This allows us to carry out manufacturer-level work without main-dealer labour rates.

After-Market Warranty Claims

We do not work directly with warranty companies. We do not raise claims on your behalf, nor do we negotiate with warranty providers. What we do provide is a thorough, accurate diagnostic report and a clear written estimate — everything you need to submit a claim yourself.

• The diagnostic session is booked and paid by the customer
• We produce a detailed, honest report of everything found
• The report clearly lists confirmed faults, required work and our estimate
• Reports are truthful — we do not adjust findings to support warranty claims
• You submit the report to your warranty company to pursue reimbursement

Whether the warranty company accepts the claim, and how much they will pay, is entirely at their discretion. Any difference between our charges and what the warranty company agrees to pay remains the customer's responsibility.

What to Expect at Your Appointment

We will talk through the symptoms with you first — your input matters. We then carry out the diagnostic session and contact you with findings before any further work is discussed. Nothing proceeds without your agreement. At the end of the process you will have a clear picture of what was found, what was confirmed through testing, and what your options are — explained honestly and without pressure.