How warning light colors work
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Red means stop safely. A critical fault or safety issue.
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Amber or yellow means caution. Drive gently and fix it soon.
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Green or blue means status. A system is on, like high beams.
1) Check Engine Light
What it means: Engine or emissions problem.
Severity: Yellow when minor. Flashing means misfire and possible catalyst damage.
What to do now: If flashing, slow down and pull over soon. Avoid hard acceleration. If solid, schedule service.
Common causes: Loose gas cap, O2 sensor, misfire, EVAP leak.
2) Oil Pressure Warning
What it means: Low oil pressure. Parts may run without lubrication.
Severity: Red.
What to do now: Pull over safely. Shut the engine off. Check oil level. Do not restart if the level is fine, but the light stays on.
Common causes: Low oil, failed pump, clogged pickup, sensor fault.
3) Battery or Charging System
What it means: Alternator or charging issue. The battery is not charging.
Severity: Red.
What to do now: Turn off non-essential electrical loads. Drive to a shop soon or stop if the power drops.
Common causes: Broken belt, bad alternator, loose or corroded terminals.
4) Engine Coolant Temperature
What it means: The Engine is overheating.
Severity: Red when hot.
What to do now: Turn off A/C. Turn on the cabin heat to reduce the temperature. Pull over and shut off the engine. Do not open the cap while hot.
Common causes: Low coolant, failed fan, stuck thermostat, leaking hose.
5) Brake System Warning
What it means: Parking brake on or low brake fluid. Sometimes, there is a hydraulic fault.
Severity: Red.
What to do now: Make sure the parking brake is fully released. If the light stays on, stop driving and call for service.
Common causes: Low fluid, worn pads, sensor, or hydraulic issue.
6) ABS Warning
What it means: Anti-lock brakes are off due to a fault. Regular brakes still work.
Severity: Yellow.
What to do now: Drive with care. Brakes can lock under hard stops. Service soon.
Common causes: Wheel speed sensor, tone ring, wiring fault.
7) Tire Pressure Monitor (TPMS)
What it means: One or more tires are low. A flashing light may mean a system fault.
Severity: Yellow.
What to do now: Check pressures when tires are cold. Fill to the door-jamb spec.
Common causes: Seasonal temperature change, puncture, slow rim leak, bad TPMS sensor.
8) Airbag or SRS
What it means: Airbag system fault. Airbags may not deploy.
Severity: Yellow or red, depending on the car.
What to do now: Wear seat belts. Avoid harsh driving. Service as soon as possible.
Common causes: Clock spring, sensor, under-seat connector, module fault.
9) Traction or Stability Control
What it means: The System is active or has a fault. A steady icon often means off or fault. A blinking icon means the system is working.
Severity: Green or yellow when active, yellow for faults.
What to do now: If faulted, drive gently and service soon.
Common causes: Wheel speed sensor, steering angle sensor, yaw sensor.
10) Power Steering Warning
What it means: Electric or hydraulic assist problem. Steering can feel heavy.
Severity: Yellow or red by model.
What to do now: Drive carefully at low speed. If steering becomes very hard, stop.
Common causes: Low fluid in hydraulic systems, electric assist fault, and belt issues.
