What your dashboard warning lights actually mean
Colour first. Red is a now problem, amber is a this week problem.
Dashboard warning lights use colour to tell you how urgent they are. Red means stop the car safely and do not keep driving. Amber means a fault has been logged and the car needs looking at soon. A flashing check engine light means stop, because it usually signals a misfire that damages the catalytic converter. Service One Automotive diagnoses warning lights at Factory 9, 266 Osborne Avenue, Clayton South VIC 3169. Ring 0434 949 091.
The colour rule
Nearly every car built in the last few decades follows the same convention, which makes an unfamiliar dashboard easier than it looks.
Red is a warning. Something is wrong right now and driving on risks damage or risks safety. Amber or orange means the car has detected a fault and logged it. Usually you can drive carefully to somewhere sensible. Green and blue are not warnings at all, they just tell you something is switched on.
Oil pressure: the one that ends engines
A red oil can symbol is not telling you the oil is low. It is telling you the oil is not being pumped around at the pressure the engine needs.
Without pressure, the bearings inside the engine are running dry, and that causes serious damage in a very short time. Pull over, switch off, check the level, and if the light stays on when you restart, have it towed.
This is the light people most often keep driving on, and it is the expensive one to be wrong about.
Temperature
A red thermometer symbol or a gauge climbing past normal means the cooling system is not coping. There is a full page on what to do about it and what usually causes it.
Check engine
The most misunderstood light on the dash, because it covers hundreds of faults across the engine and emissions systems.
Steady amber means a fault is stored. The car will usually drive normally, and it should be scanned rather than ignored, because some of the faults behind it quietly cost you fuel while doing slow damage.
Flashing is a different message entirely. A flashing engine light generally means an active misfire, and raw fuel going into a hot catalytic converter can destroy it in minutes. Reduce speed and get it looked at straight away.
Battery and charging
A red battery symbol does not mean the battery is flat. It means the charging system is not charging, so the car is now running on whatever is left in the battery.
Typically a failed alternator or a broken drive belt. You have a limited amount of driving left, and less than you would like, because the headlights and the fan are drawing from the same reserve. Head for somewhere useful rather than home.
Brake and ABS
The red brake light can be as simple as the handbrake being partly on, or as serious as low fluid from a leak. Check the handbrake first, then the fluid level.
An amber ABS light means the anti lock function has switched itself off. Your normal brakes still work, but they will lock the wheels under hard braking the way an older car does. Worth fixing before the wet weather rather than after.
A light that comes on and goes off
Still worth scanning. Most systems store a fault code even after the light clears, so a workshop can see what happened and how many times.
An intermittent light with a stored code is a much easier problem to solve than an intermittent light with no information at all.
Quick answers
Can I drive with the check engine light on?
If it is steady and the car drives normally, usually yes, to get it looked at. If it is flashing, or the car is running badly, no.
Will disconnecting the battery clear the light?
It may clear the light. It does not fix the fault, and it also wipes the stored data that would have made diagnosis quicker. It costs you more than it saves.
Why did the light come back after the shop cleared it?
Because the fault is still present. Clearing a code resets the test, and the car runs it again as soon as conditions allow.
Need it looked at?
Ring the workshop, or send a booking request.
Open weekends by booking only, at the same rates. The booking has to be confirmed before the day, so ring or text ahead.