Diagnostics
Car Diagnostics & Fault Finding in Iver
A warning light tells you something has been detected — not what has failed. We diagnose the vehicle first so the repair that follows is the repair the car actually needs.
Warning light on?
Faults we diagnose
- Engine management and warning lights
- Non-starting and intermittent starting vehicles
- Misfires, rough running and uneven idle
- Loss of power and limp mode
- Charging problems and repeated flat batteries
- Battery drain and parasitic draw
- Sensor faults across engine, fuelling and emissions systems
- DPF and diesel-specific faults
- Cooling system and temperature faults
- ABS, traction control and braking system warning lights
- Combined electrical and mechanical faults
Why diagnosis comes before parts
Fault codes point to a circuit or a reading that is out of range, and several different failures can produce the same code. Replacing parts in sequence gets expensive quickly and often leaves the original fault in place. We read live data, test the components and circuits involved and confirm the cause before recommending work.
How a diagnostic session works
- We take a clear description of the symptoms and when they happen
- Stored and pending fault codes are read across the vehicle's modules
- Live data is monitored while the fault is reproduced where possible
- Individual components, wiring and mechanical condition are tested
- You get a plain-English explanation of the cause and the options
- Any repair work is quoted before it is carried out
Cars and vans
We diagnose petrol and diesel cars and light commercial vehicles from our workshop in Iver, with customers travelling in from Slough, Langley, Uxbridge, West Drayton, Hayes, Heathrow and the wider West London and Berkshire area. If the vehicle cannot be driven, our recovery service can bring it to us.
Frequently asked questions
Warning light on?
Our work
Recent jobs from our workshop
Photographs taken during work carried out at our Iver workshop.
Carbon-choked inlet port found during diagnosis
Vehicle up on the ramp in our Iver workshop
Soot in the inlet ports after high-mileage diesel use
Advice
Helpful reading on this fault
Your engine management light is on — what now?A steady light and a flashing light mean very different things. Here is how to tell whether to book in or stop driving.Read more How to reset an engine management light — and when you shouldn'tClearing the code turns the light off. It does not fix what turned it on — and it can hide a fault that is still costing you.Read more Will an engine management light fail an MOT?An illuminated engine management light is a straight MOT fail — and clearing it the night before does not get you past the test.Read more
Symptoms
Symptoms that often lead to this repair
Look up what your car is doing and read what it commonly means.
Engine management light flashingA steady amber light and a flashing one are very different. Flashing normally indicates a misfire severe enough to risk expensive damage.Read more Car stuck in limp modeLimp mode is a protection strategy, not a fault in itself. The control unit has seen a reading it does not trust and has reduced power to keep things safe.Read more Glow plug (coil) light flashing on a dieselOn many diesels the coil symbol doubles as an engine fault warning. A flashing light usually means a stored fault, not necessarily a glow plug.Read more ABS warning light onWith the ABS light on, the anti-lock function has typically disabled itself. The brakes usually still work, but without anti-lock support in an emergency stop.Read more Brake pedal feels spongy or goes to the floorA firm pedal is what tells you the hydraulic system is sealed and healthy. Sponginess means something in that system has changed.Read more Car cutting out while drivingIntermittent cut-outs are among the most important faults to record properly, because the evidence disappears the moment the engine restarts.Read more Air conditioning not blowing coldAir conditioning loses a little refrigerant over the years, but a system that has gone warm quickly usually has a leak worth finding.Read more Flat battery: why it keeps going flatBatteries do wear out, but a battery that flattens repeatedly usually has help — either it is not being charged properly or something is draining it while the car is parked.Read more Car shaking or vibrating at idleIdle is where small faults show up most, because the engine has no load to smooth them out.Read more Heavy steering or a power steering leakSome cars use hydraulic power steering, others electric. The symptoms overlap but the causes and checks are very different.Read more Brake warning light onThe brake warning light covers several different systems, so the first job is establishing which one has triggered it.Read more Airbag warning light onThe airbag light means the restraint system has logged a fault and may not deploy correctly, so it is worth reading properly rather than clearing.Read more Car won't start but the battery is fineWhen the battery tests healthy, the fault is usually in the starting circuit, the fuel side or the sensors the engine needs to run.Read more Car battery keeps going flatRepeatedly flat batteries are rarely bad luck. Something is either draining the battery, failing to charge it, or the battery itself is finished.Read more Air conditioning smells mustyThe smell normally comes from moisture sitting where it should not, rather than from the refrigerant side of the system.Read more
Related
You may also need
Car Won't Start?A car that will not start is not one fault — it is a shortlist. Working through that list in order is how you avoid buying parts you did not need.Read more Engine DiagnosticsEngine faults are usually a chain of events rather than a single broken part. We test fuelling, ignition, air, compression and control signals to find where the chain breaks.Read more Diesel DiagnosticsModern diesels combine high-pressure fuelling, turbocharging, exhaust gas recirculation and after-treatment. When one part of that system drifts, the symptoms usually show up somewhere else.Read more DPF DiagnosticsA DPF warning is the end of a chain of events, not the start. Finding out why the filter is loading up is the part that saves money.Read more Car Battery ReplacementModern batteries are not just a box of power. On many vehicles a new battery has to be the right type and registered to the car.Read more Vehicle RecoveryBroken down, non-runner, or a car that needs moving? We tow and recover cars and light commercials across West London, Berkshire and South Buckinghamshire — and bring them straight to our own garage for repair.Read more
Talk to us about car diagnostics & fault finding in iver
Based in Iver, covering West London, Berkshire and South Buckinghamshire. Send your registration and we will quote for your vehicle.