If a MAINT REQD light has appeared on your dashboard, there is no need to worry. It is a reminder that scheduled servicing is due - not a warning that something has broken.
It is worth understanding exactly what it means, though, because it is regularly confused with the check engine light, which is a different thing entirely and should not be ignored.
What the maintenance required light actually is
MAINT REQD, sometimes shown as MAINT or a spanner symbol, is a mileage counter. It is set when the car leaves the factory or when the last service was logged, and it counts down the distance to the next one. It is not connected to any sensor and it knows nothing about the condition of your engine.
On most Toyota and Lexus models it works to a 5,000-mile cycle: the light flashes for a few seconds each time you start the car once you pass about 4,500 miles, and stays on permanently from 5,000. Other manufacturers use a similar counter under a different name.
The most common false alarm is simple: the previous service was done, but whoever did it forgot to reset the counter. The light then appears at exactly the wrong moment and means nothing at all.
Maintenance required is not the check engine light
This is where most of the confusion comes from. The two lights sit next to each other, look similar and mean completely different things:
- MAINT REQD is a calendar. It counts miles and tells you a service is due. You can keep driving normally.
- Check engine is a diagnosis. It appears when the engine control unit has logged a fault code and something in the engine, emissions or fuel system needs looking at. It should not be ignored, and a flashing check engine light means stop as soon as it is safe.
- The red lights - oil pressure, coolant temperature, brake system, battery - mean stop now. They are the ones that turn a repair into a replacement if you drive on.
What the light is asking for
At a minimum, an oil and filter change. Most maintenance schedules pair that with a tyre rotation, a check of the brakes, fluid levels, filters and belts, and a look at the suspension and exhaust. The exact list is in your owner's manual and varies by model and mileage.
Bigger intervals - 30,000, 60,000, 90,000 miles - add items such as spark plugs, transmission fluid, coolant and, on some engines, a timing belt. Those are the expensive ones, and they are the reason it pays to know which interval you are actually at rather than simply booking an oil change.
How to reset it
A garage will reset the counter as part of the service. If you change the oil yourself, you reset it yourself - and this is the one thing worth being careful about, because resetting the light without doing the work simply removes the reminder.
On most Toyota and Lexus models: turn the ignition to on with the engine off, set the display to trip A, turn the ignition off, then hold the trip reset button while turning the ignition back to on and keep holding until the display shows 000000.
On many other cars the reset lives in the instrument cluster or infotainment menu, typically under vehicle settings, service, or maintenance intervals. The exact sequence differs by manufacturer and model year, so check your owner's manual rather than a generic procedure.
Dashboard warnings you should not ignore
While you are looking at the dashboard, these are the ones that actually matter. Several of them mean pull over rather than book an appointment.
Engine oil pressure
Low oil pressure can mean a leak in the oil circuit, too little oil in the engine, a failing pump or worn bearings. This is a stop-immediately light: an engine running without oil pressure can destroy itself in minutes.
Check engine
An engine outline or the words CHECK ENGINE. The causes range from a loose fuel cap to a failing mass airflow sensor, an ignition fault or a problem with the oxygen sensor or catalytic converter. Steady means have the codes read soon; flashing means an active misfire, which can damage the catalytic converter, so stop when safe.
Power steering
A steering wheel symbol. Amber usually indicates a system that needs attention or relearning; red, particularly with an exclamation mark, means the electric or hydraulic assistance has failed. The car remains steerable, but the wheel becomes very heavy, so drive slowly and directly to a garage.
ABS and brake system
The ABS light means anti-lock braking is disabled - the brakes still work, but they can lock under hard braking. The separate red BRAKE light is more serious and can mean low fluid, a hydraulic fault, or simply that the parking brake is still engaged. On some cars it also indicates a failed brake light bulb.
Airbag
A fault somewhere in the supplementary restraint system. The airbags may not deploy in a collision, and in rare cases may deploy when they should not. It cannot be diagnosed by eye and needs a scan tool.
Coolant temperature
A red thermometer means the coolant has reached a critical temperature and the gauge is in or near the red zone. Stop, switch the engine off and let it cool. Driving on overheats the head gasket and, eventually, the engine itself.
Seat belt
The driver or a passenger is unbelted. Straightforward, but worth acting on: an unbelted occupant is at far greater risk in even a low-speed impact, and the airbag is designed to work with the belt rather than instead of it.
Door ajar
A symbol showing the car from above with a door open, or a DOOR AJAR message. Usually a door, boot or bonnet that has not latched properly - but a bonnet that is not latched is a genuine hazard at speed.
What the colours mean
As a rule of thumb: green or blue is information, amber is a warning that something needs attention soon, and red means a serious problem that requires you to stop. Red oil pressure or coolant temperature warnings mean stop now, not at the next exit.
That said, the symbols are not fully standardised. Some are common to all cars, others are specific to a manufacturer, and very similar-looking icons can mean quite different things on American, European, Japanese, Korean and Chinese vehicles. When in doubt, the owner's manual is the authority.
If you are buying a used car with the light on
A maintenance required light on a car you are viewing is worth asking about. If the seller says it has just been serviced and the light was not reset, ask for the invoice. If it has simply been ignored for months, that tells you something about how the rest of the car has been treated.
Either way, pull the vehicle history by VIN before you commit. Service entries, mileage records and accident history put the light in context - and a car with an ignored service reminder and no records behind it is a different proposition from one with a folder of invoices.
The bottom line
The maintenance required light is a reminder, not a fault. Book the service, have the counter reset, and keep the invoice - it is worth money when you sell the car.
What you should not do is get used to ignoring lights. Learn which ones on your dashboard mean stop, keep to the schedule in your manual, and check the VIN history on any used car whose reminder has been lit for a while.
