Dashboard warning lights
Grouped by what they demand of you, not alphabetically. If a light just came on and you are deciding whether to keep driving, the answer is near the top of this page.
Colour is the fastest first read: red generally means stop or act now, amber and yellow mean a fault needs attention, green and blue are usually telling you a system is switched on. Manufacturers vary, so the colour is a strong hint rather than a rule.
Continuing risks injury or major damage. Pull over when it is safe.
- Brake System Warning LightThree different things turn this on: the parking brake is applied, the brake fluid is low, or one hydraulic brake circuit has lost pressure. Rule out the first one, and the other two are serious.red
- Engine Coolant Temperature Warning LightThe engine is running hotter than it can safely tolerate. Aluminum cylinder heads warp and head gaskets fail from heat, and both happen faster than most drivers expect.red
- Oil Pressure Warning LightOil is not reaching the engine's bearings at the pressure it needs. This is the one light where the difference between stopping now and driving another mile can be the difference between a cheap repair and a new engine.red
- Transmission Temperature Warning LightThe automatic transmission fluid is hotter than the manufacturer allows. Heat is what kills automatic transmissions: hot fluid loses its film strength, varnishes the valve body, cooks the friction material off the clutch plates and hardens the seals. Damage accumulates for as long as the light is on. This is one of the few non-red warnings that genuinely means stop and deal with it now.varies
Get off the road and get it looked at rather than continuing a journey.
- Battery / Charging System Warning LightThe charging system is not keeping up, so the car is running on stored battery power. When the battery drains, the engine stops — and it will not restart.red
- Power Steering Warning LightThe power steering system has a fault and assist is reduced or switched off. On virtually all vehicles the steering stays mechanically connected — the wheel still turns the front wheels — but the effort required can rise dramatically, most of all at parking speeds. Two caveats matter. A seized assist motor, a binding column, or a damaged rack can make the wheel feel notchy, catchy, or heavy in one direction rather than merely stiff everywhere. And a small but growing number of steer-by-wire vehicles have no continuous mechanical link at all and depend on a backup mode instead. So: if the wheel still turns smoothly and is simply heavy, expect to steer as though the car has no power steering, and expect that change to arrive without warning. If it binds, catches, or is heavy in only one direction, stop and have it towed rather than driven.amber
Usually driveable, but the fault will not clear itself.
- ABS Warning LightIn most cases the anti-lock system has shut itself off and your base brakes still work — but confirm that before you rely on it: the red brake warning light must be off, and the pedal must feel normal and hold firm. Low brake fluid and hydraulic unit faults can also light this lamp, and those do affect actual braking. What an ABS shutdown by itself costs you is the wheels-not-locking function, and usually traction and stability control with it.amber
- Airbag / SRS Warning LightThe airbag control module found a fault in itself or in something it monitors, and stored a code. On most vehicles it also shuts the restraint system down, so airbags and seat belt pretensioners will not fire in a crash. It does not mean an airbag is about to go off on its own, and it does not mean an airbag is broken — it means the module can no longer vouch for the system.red
- Check Engine LightThe engine computer found something outside its programmed limits and stored a trouble code. The code names what the computer measured, not which part failed.amber
- Glow Plug / Preheat Indicator (Diesel)At key-on this is not a warning at all. It means the glow plugs are heating the combustion chambers so a cold diesel will light off; you wait for it to go out, then crank. It becomes a fault indication when it stays on after the engine is running, comes on while you are driving, or flashes — and on a number of makes a flashing preheat lamp is the general engine-management warning rather than anything to do with glow plugs.amber
- Tire Pressure Monitoring System (TPMS) LightSteady: at least one tire has fallen to or below the pressure the system watches for. On US vehicles built since September 2007 that threshold is 25 percent below the placard pressure, which is already low enough to hurt braking, handling and tire life — the light is late, not early. Flashing for about a minute at startup and then going solid means something different: the monitoring system itself has a fault and is not watching your tires at all.amber
- Traction Control / Stability Control LightSteady illumination of the plain skidding-car lamp normally means the system has detected a fault and shut itself down — you are driving without that safety net. Manual switch-off lights the separate TC OFF / ESC OFF / VSC OFF telltale on most vehicles, so check whether an OFF lamp or OFF text is showing too; a few makes light both, but the plain lamp on its own should be treated as a stored fault, not as somebody's button press. Flashing means the opposite of a fault: the system is working right this second, cutting power or braking a slipping wheel. Your ordinary brakes still work — unless the red brake warning lamp is on as well, which is a different and far more urgent problem.amber