A warning light is the car asking a question. We find the answer within the hour.
We connect dealer-level scan tools to every control module, read what the car has recorded, test what the code points to, and phone you with a plain-English finding and a fixed quote before anything is repaired.
Reading the car, not guessing
Every modern car keeps a record of its own health. Dozens of control modules monitor sensors thousands of times a second, and when a reading drifts outside the tolerance the manufacturer set, the module stores a fault code and, if it matters enough, lights the dash. Those codes are the starting point of every diagnosis we do, but they are only the starting point.
At Autoworld we connect dealer-level scan tools to every module on the car and pull a full systems health report. Then we look at the live data and freeze-frame recorded with the fault, test the component or circuit the code points to, and confirm the cause before quoting a repair. The result is a plain-English explanation of what is wrong, how urgent it is, and a fixed price to fix it, usually within the hour of the car arriving.
Finding a fault early is the whole point. Problems that sit undiagnosed get worse, take other parts with them, and turn a small repair into an expensive one. A diagnosis is the cheapest hour you will spend on the car.
Emission faults, diagnosed within the hour
Diesel emission systems are where we see the most warning lights: blocked diesel particulate filters, sticking EGR valves, AdBlue level and quality faults, and NOx sensor failures. These are our specialty. We diagnose the cause within the hour and offer a full range of solutions, from forced regeneration and cleaning to component replacement, on cars, utes, vans, motorhomes and trucks. We fix the fault rather than silencing the light.
A simple guide to common warning lights
Not sure what the symbol means? Here are the ones we are asked about most.
Oil pressure or oil level (the red oil can)
Shown in red or orange, this means one of two things: the oil level is low, or the engine has lost oil pressure. Either can destroy an engine in minutes. If it stays on, pull over, switch off and call us before driving any further.
Check engine (the engine outline)
The most common light on the road. It covers any fault the engine control unit sees in the engine, fuel, ignition or exhaust and emission systems. The car may still drive perfectly, but the fault is real and worth finding. Book a diagnosis; we will read the data and tell you what it means and what to do.
Engine temperature (the thermometer)
On many cars this light has replaced the temperature gauge. Blue means the engine is still cold and warming up, and it goes out at normal running temperature. Red, or flashing, means the cooling system is above its safe threshold. Stop as soon as it is safe and get the car to us. Driving on can warp a cylinder head or worse.
Hybrid and EV system warnings
Hybrids add a few of their own: a high-voltage system warning, a hybrid battery light or a “check hybrid system” message. These need a technician with the right tools and high-voltage training. We have both, and we test the pack cell by cell rather than condemning it on a code.
Regular servicing is the best way to keep all of these lights off the dash. Every Autoworld service package above Express includes the same full systems scan we use for diagnosis, so faults are caught before they become warnings.
What happens next
Book a diagnosis online, send an enquiry below, or call 022 3900 587. If a red warning light is on, call first. We confirm every booking by text or email. We phone you with the findings and a fixed quote within the hour, and no repair goes ahead until you have approved it.
Common questions
Can I keep driving with the check-engine light on?
Often the car will drive normally, but the light means the engine computer has stored a fault outside its tolerance, and faults left alone tend to get worse and more expensive. If the light is flashing, or you have lost power, stop driving and call us. Otherwise book it in soon; the first hour of diagnosis will tell you what you are dealing with.
Why not just clear the code?
Clearing a code wipes the evidence without fixing the cause, and the light comes straight back. We read the freeze-frame data stored with the code, test the component or circuit it points to, and fix the actual fault. Emission faults in particular are never 'reset'; we repair them properly.
What does the diagnosis cost and does it include the repair?
Diagnosis is charged as a separate step from any repair. Once we know the cause we phone you with findings and a fixed quote for the fix, and nothing further is done until you approve it.
My car is European. Can you read it properly?
Yes. Generic code readers only see the engine on most European cars. We use dealer-level diagnostic equipment for BMW, Mercedes-Benz, Audi, Volkswagen, Skoda and Volvo that reads and tests every module, including gearbox, body and driver-assistance systems.
My DPF or AdBlue warning is on. Is that a diagnostics job?
It is, and it is one we do every day. We diagnose DPF, EGR, AdBlue and NOx sensor faults within the hour and offer a full range of repair options, from forced regeneration to component replacement. See our exhaust and emissions page for more.
Enquire or book: Engine diagnostics
Tell us about the car and what it needs. We reply within the hour during workshop hours and confirm every booking by text or email.
Thanks, your enquiry is on its way.
We will confirm your booking by text or email, usually within the hour during workshop hours.