What does it mean when the OBD light comes on in the car?

[SanJordan]

OBD engine fault light indicates an emission fault in the vehicle. Here are specific introductions to other warning lights in the car: 1. EPS stands for Electric Power Steering system. When the EPS warning light flashes on the dashboard, it is recommended to stop driving and have it inspected at a repair shop or 4S store. Problems with the electric power steering system may lead to loss of steering assistance, making the steering wheel heavier. If encountering an emergency situation, immediate action should be taken to avoid it. 2. Tire pressure warning light: When this symbol appears, it indicates abnormal tire pressure in the vehicle's tires, and they should be checked promptly. 3. Water temperature indicator light: This light typically comes on when the car is first started, especially in winter, displaying a blue thermometer-like shape. It will illuminate when the water temperature is either too high or too low. If the water temperature is too high, do not continue driving; stop immediately. Once the water temperature returns to normal, proceed to the nearest 4S store or auto repair shop for inspection.

[VonDeclan]

That day while driving, I suddenly noticed the OBD light illuminated on the dashboard and immediately pulled over to check the manual. This light is officially called the OBD Malfunction Indicator Lamp, specifically monitoring the engine and emission systems. Common causes include a loose fuel cap, carbon buildup on the oxygen sensor, or a dirty air filter leading to incomplete combustion. I once encountered a situation where the sensor connector came loose, and simply reconnecting it solved the problem. The most troublesome issue was a failing catalytic converter - last time replacing it cost me over 2,000 yuan. I recommend first visiting an auto repair shop to read the trouble codes, unlike me who stubbornly drove for half a month and failed the annual inspection due to excessive emissions. It's best to clean the throttle body quarterly as effective prevention.

[CamilaRose]

When the OBD light on the dashboard turns yellow, it indicates an emission anomaly has been detected, but don't rush to hit the brakes. There's an 80% chance it's a sensor issue, especially during sudden temperature changes. My old car last winter had a false alarm due to the exhaust pressure sensor freezing up. Aging wiring is also a potential hazard, as rainwater seeping into the engine compartment can cause short circuits. You can start by checking if the fuel tank cap has any gaps, then drive about ten kilometers to let the system self-calibrate. If the light turns red, you must stop immediately, as this signifies a severe engine malfunction. The last time I encountered this, I had to tow it to the repair shop, and the diagnosis revealed a clogged fuel injector causing the fuel trim value to exceed limits. Remember to regularly use specialized cleaner and drive at high speeds to prevent many faults.

[EdenDella]

The day the OBD light came on, I was driving on the highway and quickly checked information on my phone. It turned out to be the onboard diagnostic system alerting, most commonly due to fuel quality issues. I tried filling up with 98-octane gasoline for two full tanks, and the light went off on its own. Last time in Tibet, I refueled at a private gas station, and the light came on—diagnostics showed an oxygen sensor poisoning. Another scenario was aftermarket audio wiring interfering with ECU signals. I recommend keeping a Bluetooth OBD scanner plugged into the port under the steering wheel; for just a few bucks, you can read fault codes. For instance, a code like P0171 indicates a lean fuel mixture—simply replacing the air filter might solve it, no need to fall for repair shops pushing full sensor replacements.