Type a warning light name (e.g. "check engine", "ABS", "airbag") and find out what it means, how serious it is, and whether you can keep driving.
Oil Pressure Warning Light
CriticalEngine oil pressure has dropped below a safe level, meaning moving parts inside the engine may not be getting enough lubrication.
Battery / Charging System Warning Light
CriticalThe battery is not being charged properly by the alternator - the car is running on stored battery power alone.
Brake System Warning Light
CriticalThis red light points to a problem with the braking system itself - most often low brake fluid, but it can also mean a hydraulic fault or uneven brake pressure between circuits.
Coolant Temperature Warning Light
CriticalThe engine coolant temperature has climbed above the safe operating range - the engine is overheating.
Airbag / SRS Warning Light
CriticalThe supplemental restraint system (airbags and seatbelt pretensioners) has detected a fault. The airbags may not deploy correctly in a crash, or could deploy unexpectedly.
Transmission Temperature Warning Light
CriticalThe automatic transmission fluid has overheated beyond its safe operating temperature.
Brake Fluid Level Warning Light
CriticalA dedicated sensor in the brake fluid reservoir has detected the fluid level dropping below the minimum mark, separate from the general brake system light on some vehicles.
Check Engine Light
WarningThe engine control unit has detected a fault somewhere in the engine, transmission, or emissions system and stored a trouble code (a "P" code) explaining what went wrong.
Parking Brake Warning Light
WarningThis light most commonly just means the parking brake is engaged, but if it stays on after you release it, it can share the same circuit as the brake fluid warning.
ABS Warning Light
WarningThe anti-lock braking system has detected a fault and disabled itself. Normal brakes still work, but you lose anti-lock protection during hard braking.
TPMS Warning Light (Low Tire Pressure)
WarningA horseshoe-shaped light with an exclamation point means the tire pressure monitoring system has detected one or more tires below the recommended pressure. If it flashes for about a minute then stays on, the TPMS system itself has a fault rather than the tires.
Master Warning Light
WarningA general-purpose alert (usually a red or amber exclamation mark or triangle) that lights up alongside a specific message on the instrument cluster display, pointing to a variety of possible issues.
DEF Warning Light (Diesel Exhaust Fluid)
WarningThe diesel exhaust fluid (DEF, also branded AdBlue) used to reduce emissions in modern diesel engines is running low.
Diesel Particulate Filter (DPF) Warning Light
WarningThe diesel particulate filter, which traps soot from the exhaust, is clogged and needs to regenerate (burn off the trapped soot) or is otherwise faulty.
Power Steering Warning Light
WarningThe power steering system (electric or hydraulic) has detected a fault, meaning steering may suddenly become much heavier.
Brake Pad Wear Warning Light
WarningA wear sensor embedded in the brake pads has made contact with the rotor, signaling that the pads are close to or past their minimum thickness.
EPC Warning Light (Electronic Power Control)
WarningFound mainly on Volkswagen, Audi, Seat, and Skoda vehicles, this light indicates a fault in the electronic throttle control system, which manages engine power delivery.
Forward Collision Warning Light
WarningThis light indicates a fault or temporary unavailability of the forward collision warning or automatic emergency braking system, which normally watches the road ahead for a possible collision.
AWD / 4WD Warning Light
WarningThe all-wheel-drive or four-wheel-drive system has detected a fault and may have reduced or disabled power transfer to the secondary axle.
Catalytic Converter Warning Light
WarningThis appears as part of the check engine light system when the ECU specifically detects the catalytic converter is not cleaning exhaust gases efficiently.
Seatbelt Reminder Light
InfoThe system has detected that the driver or a passenger is not wearing a seatbelt, usually combined with a chime.
Traction Control / Electronic Stability Control Light
InfoThis light (usually a car icon with wavy skid lines) flashes briefly when the traction or stability control system is actively working to keep the car stable, for example on a slippery surface.
ESC Off / Traction Control Off Light
InfoThe driver has manually turned off the electronic stability control or traction control system, usually with a dedicated dashboard button.
Glow Plug Warning Light (Diesel)
InfoOn diesel engines, this coil-shaped light shows the glow plugs are preheating the combustion chambers before starting - completely normal. It becomes a fault indicator only if it flashes or stays on after the engine is running.
Low Fuel Warning Light
InfoThe fuel level has dropped to a reserve level, typically representing somewhere between 30 and 80 km (20-50 miles) of remaining range depending on the vehicle.
Washer Fluid Warning Light
InfoThe windshield washer fluid reservoir is running low.
Door Ajar Warning Light
InfoOne or more doors, or sometimes the trunk/hatch, is not fully closed.
Hood Open Warning Light
InfoThe hood latch sensor detects the hood is not fully closed and secured.
Immobilizer / Security Light
InfoUsually a blinking light with a car and lock or key icon, showing the anti-theft immobilizer system is armed, or flagging that it does not recognize the key trying to start the car.
Lane Departure Warning Light
InfoThis light shows the status of the lane departure warning or lane keeping assist system, which alerts you (or gently steers you back) if you drift out of your lane without signaling.
High Beam Indicator Light
InfoA simple status light (usually blue) confirming the high-beam headlights are currently on.
Fog Light Indicator Light
InfoA status light confirming the front or rear fog lights are switched on.
Hazard Light Indicator
InfoShows that the hazard warning flashers (all four turn signals blinking together) are switched on.
Cruise Control Indicator Light
InfoConfirms cruise control (standard or adaptive) is currently active and maintaining your set speed.
Oil Change Reminder Light
InfoA mileage or time-based maintenance reminder (usually a wrench icon), not a fault - it just means scheduled service, most commonly an oil change, is due soon.
Key Fob Battery Low Light
InfoThe battery inside the wireless key fob is running low, which can eventually affect remote locking, unlocking, or keyless start range.
Park Assist / Parking Sensor Fault Light
InfoThe ultrasonic parking sensors or automatic parking assist system has detected a fault and may be temporarily unavailable.
Adaptive Headlight Fault Light
InfoThe adaptive front lighting system, which swivels or adjusts headlights based on steering angle and speed, has detected a fault.
Find a trusted auto repair shop near you and book a diagnostic visit online in minutes.
Find a repair shopRun a shop? The OBD decoder, fuse box diagrams and parts catalog are built into the Motoro dashboard. See Motoro for workshops
Descriptions are for guidance only and do not replace a workshop inspection. If you are ever unsure whether it is safe to keep driving, pull over in a safe spot.