Short answer: a steady light means have it checked soon, and a flashing one means slow down and have it checked now. For a roadworthy in Victoria the light does not decide the result by itself. The fault behind it does.
Steady or flashing
A MINI owner's manual published by BMW Group describes the emissions warning light on page 281. It is a US English edition, so check the manual that came with your own car.
A steady light:
The warning light lights up: Emissions are deteriorating. Have the vehicle checked as soon as possible.
A flashing light:
The warning light flashes under certain circumstances: This indicates that there is excessive misfiring in the engine. Reduce the vehicle speed and have the system checked immediately; otherwise, serious engine misfiring within a brief period can seriously damage emission control components, in particular the catalytic converter.
The difference is urgency. A flashing light is the manual telling you that continuing to drive hard can damage the catalytic converter.
The light is one part of a wider system, which the same manual describes on page 127.
The Check Control system monitors functions in the vehicle and notifies you of faults in the monitored systems.
Will it fail a roadworthy?
Victoria's roadworthiness standard is Vehicle Standards Information 26, the written directions a licensed vehicle tester works to. Its section on the engine and driveline has one sentence on this.
Check engine lamp may be illuminated if it can be established that the fault code does not cause the vehicle to operate in limp mode, have any impact on a safety system or have any impact on the operation of the vehicle emissions system.
Read it carefully, because it cuts both ways. The light may be on and the car may still pass. But only if it can be established what the fault code is, and that it does none of three things: put the car into limp mode, affect a safety system, or affect the emissions system.
So a check engine light is not an automatic fail, and it is not something a tester can wave through either. The code has to be read.
Other warning lights are stricter
The same standard treats the brake system's warning lights differently. Its section on brakes says this.
Where ABS or ESC (or EBS for trailers) is fitted on a vehicle as standard, it must operate correctly. A fault with the operation of these systems is determined by the presence of a warning light.
For ABS and stability control, the light being on is the fault. There is more on that in our post on what a roadworthy requires of your brakes.
Why the code matters more than the light
A light tells you a fault has been recorded. It does not tell you which one, and not every stored fault turns a light on. As we say on our BMW service page, a modern BMW can run with a fault stored in a module that never lights the dashboard.
That is why a warning light is the start of a diagnosis rather than the diagnosis.
How we handle it
We run full computer diagnostics, including stored and pending fault codes, and tell you what was found before any work is quoted.
It helps to tell us what the light was doing: steady or flashing, when it came on, and whether the car felt different.
BM Garage is a licensed vehicle tester, so if the light is the thing standing between your car and a roadworthy certificate, the diagnosis, the repair and the inspection can happen here.
Every car is different, so we quote on the car rather than from a list. Send us the year, model and rego along with what it needs, and we will put a tailored quote together.
Sources
- MINI Hardtop 2 Door / 4 Door Owner's Manual, BMW AG, US English edition, part no. 01405A541B0 - II/22. Pages 127 and 281. Published on BMW Group's own server.
- Vehicle Standards Information 26: Roadworthiness requirements, State of Victoria, Department of Transport and Planning, March 2023. Section C, Brakes, and Section J, Engine and driveline.
Every quotation above is taken word for word from those two documents. Manuals differ by model and year, so check your own.
Common questions
What does a steady check engine light mean on a BMW or MINI?
A MINI owner's manual published by BMW Group says that when the emissions warning light lights up, emissions are deteriorating, and the vehicle should be checked as soon as possible.
What does a flashing check engine light mean?
The same manual says a flashing light indicates excessive misfiring in the engine. It says to reduce the vehicle speed and have the system checked immediately, because serious misfiring can within a brief period seriously damage emission control components, in particular the catalytic converter.
Does a check engine light fail a roadworthy in Victoria?
Not automatically. Victoria's roadworthiness standard, VSI 26, says the check engine lamp may be illuminated if it can be established that the fault code does not cause the vehicle to operate in limp mode, have any impact on a safety system or have any impact on the operation of the vehicle emissions system. So it depends on what the stored fault is.
Is an ABS or stability control light treated the same way?
No. VSI 26 says that where ABS or ESC is fitted as standard it must operate correctly, and that a fault with these systems is determined by the presence of a warning light.