Engine management light on — what should I do?
Steady versus flashing, what it can mean, and why clearing it without a diagnosis is a false economy.
A steady engine management light means the car has logged a fault it thinks you should know about. You can usually keep driving sensibly and book it in. A flashing light means a misfire severe enough to damage the catalytic converter — stop when safe and ring us.
The light itself tells you nothing about the cause; it could be a loose fuel cap, a sensor, a coil, an emissions fault or wiring. Clearing it with a cheap reader just hides it until it comes back, often as a more expensive job.
Proper diagnosis means reading the fault codes with the live data around them, testing the suspect component and wiring, and fixing the cause. On Ford, Stellantis, Mercedes, VW Group and JLR we use the dealer-level system, which includes the manufacturer's own guided tests for that exact fault.
Need it looking at? Book online or ring 01664 793055. Written by the team at Oswins Garage, Melton Mowbray.
Questions people ask
Will it fail the MOT?
Yes — an engine management light on is an MOT failure.
How much is a diagnostic check?
A fixed fee agreed before we start; it is deducted from the repair if you have the work done with us.