Dashboard warning lights: what they mean
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The colour of a warning light tells you how urgent it is. A red light (oil pressure, temperature, brakes) means stop safely and switch the engine off. A yellow light (check engine, ABS, tyre pressure) usually means you can drive on carefully but should get the car checked soon. A flashing check engine light is serious.
Check engine light
Colour: yellow
The engine computer has found a fault and stored a fault code. A steady yellow light usually isn't urgent. If the light is flashing, the engine is misfiring.
What to do
If the light is steady, drive gently and have the code read soon. If it's flashing, slow down and stop as soon as it's safe.
Related fault codes
Oil pressure light
Colour: red
There isn't enough oil pressure in the engine. Without oil pressure the engine can be ruined within minutes.
What to do
Stop the car right away and switch the engine off. Check the oil level. If the oil is fine and the light stays on, don't drive any further.
Related fault codes
Battery (charging) light
Colour: red
The alternator isn't charging the battery. The car keeps running on the battery alone until it goes flat.
What to do
Switch off anything you don't need (A/C, heated seats) and drive straight home or to a workshop. Don't switch the engine off on the way, it may not restart.
Related fault codes
Brake warning light
Colour: red
The handbrake is on, the brake fluid is low or there's a fault in the brake system.
What to do
Check that the handbrake is fully released. If the light stays on or the pedal feels soft, don't drive. Have the car towed.
Related fault codes
Coolant temperature light
Colour: red
The engine has overheated or the coolant is low.
What to do
Stop and switch the engine off. Don't open the hot expansion tank cap. Check the coolant only once the engine has cooled down.
Related fault codes
ABS light
Colour: yellow
There's a fault in the anti-lock braking system. Normal braking still works, but the wheels can lock under hard braking.
What to do
You can drive carefully. Leave more braking distance and have it checked soon. A wheel speed sensor is a common cause.
Related fault codes
Airbag light
Colour: red
There's a fault in the airbag or seatbelt pretensioner system. The airbags may not deploy in a crash.
What to do
The car drives normally, but have it checked soon. A connector under a seat is often the cause.
Tyre pressure light (TPMS)
Colour: yellow
One or more tyres is low on pressure. Pressure naturally drops in cold weather.
What to do
Check and inflate the tyres to the right pressure (see the sticker on the door or fuel flap). If the light comes back, a tyre may have a slow puncture.
Glow plug light (diesel)
Colour: yellow
If it comes on briefly before starting, that's normal. If it flashes while driving, there's an engine management fault.
What to do
If it flashes while driving, drive gently and have the codes read. The car may go into limp mode.
Related fault codes
Diesel particulate filter (DPF) light
Colour: yellow
The diesel particulate filter is full and needs to clean itself.
What to do
Drive for 20–30 minutes on a motorway at a steady speed. If the light stays on, bring the car in before the filter blocks completely.
Related fault codes
Power steering light
Colour: yellow or red
There's a fault in the electric power steering. The steering may become heavy.
What to do
Drive carefully, the steering may be heavy. Switch the ignition off for a few minutes and restart. If the light stays on, have it checked.
ESP / traction control light
Colour: yellow
If it flashes on a slippery road, the system is working and all is well. If it stays on, the system is switched off or faulty.
What to do
If it flashes, ease off. If it stays on, drive carefully and have it checked; it often comes on together with the ABS light.
Related fault codes
Want a definite answer?
Bring the car to our workshop in Estonia for diagnostics. We read the fault codes, test the sensors and tell you what is wrong. Repair price depends on the work involved, generally €45 per hour.
Frequently asked questions
What's the difference between red and yellow warning lights?
Red means stop safely and switch the engine off. Yellow means there's a fault, but you can usually drive on carefully and get the car checked soon.
Will the check engine light fail the MOT / annual inspection?
A lit check engine light is recorded as a defect at the Estonian roadworthiness inspection. Have the code read and fixed beforehand. Simply clearing it doesn't help, because the readiness monitors show the codes were recently cleared.
Why does a warning light come on and then go off by itself?
Often the fault is intermittent: a loose connector, a weak battery or low tyre pressure in the cold. The engine computer still stores the code, so it can be read later.
Several lights came on at once – what's wrong?
When the ABS, ESP and check engine lights come on together, there's often a single cause: a weak battery, a wheel speed sensor or the sensor supply voltage. Start by checking the battery.