If you observe any of the above warning lights and it comes on while you are driving, DO NOT IGNORE THEM! Immediate action may be required to prevent damage to your car, a breakdown or an accident.
OIL PRESSURE WARNING LIGHT
The oil pressure warning light will come on if your engine has lost oil pressure or oil pressure is too low for safe engine operation. You should pull over to the side of the road, turn off the engine off and check the oil level on the engine dipstick.
Possible Causes: Low oil level (Because of oil consumption or leaks), oil viscosity too thin, worn oil pump, excessive engine bearing clearances or defective oil pressure sending unit.
If your engine is also making ticking, clattering or rapping noises, it is not getting sufficient oil. If you continue to drive the engine in this condition, you will probably damage it – if it has not already suffered major internal damage.
TEMPERATURE WARNING LIGHT
The temperature warning light will always come on if your engine is overheating. Do NOT keep driving if your engine is overheating as this can cause expensive engine damage (piston scuffing, valve stem galling, failed head gasket, cracks or distortion in cylinder head). Stop driving, pull over and shut your engine off. Open the hood and check the radiator and heater hoses, radiator and engine for coolant leaks. Check the level of the coolant in the coolant reservoir.
CAUTION: DO NOT open the coolant reservoir or radiator cap until the engine has cooled off for at least 30 minutes. Steam pressure inside the cooling system can blow out and burn you!
If the coolant level is low, include coolant (a 50/50 mixture of antifreeze and clean distilled water) after the engine has cooled down.
Possible Causes: Low coolant level (because of coolant leak or bad head gasket), stuck thermostat, bad water pump, broken serpentine belt, defective radiator cooling fan, clogged or dirty radiator, exhaust restriction (plugged catalytic converter).
HINT: Turning the A/C OFF and turning the heater on HIGH may assist cool down an engine that is temporarily overheating because of an unusually hot weather or from towing a trailer. But if the engine is running hot since it is low on coolant, this trick probably won’t help much.
CHARGING SYSTEM WARNING LIGHT
The “GEN” or “ALT” warning light, or an icon of a battery will come on if the charging voltage in your car is low. You do not have to stop immediately, but you may only have 20 to 30 minutes of driving time before your battery goes dead and your engine stops running (or even less time if you are driving at night with your headlights on).
Possible Causes: Broken or slipping serpentine belt or V-belt, bad alternator, charging control fault, or loose or corroded battery cables.
Open the hood to check if the drive belt that turns the alternator is intact and is turning the alternator while the engine is idling. If the belt is not the issue, chances are the charging system has an issie that will have to be diagnosed and repaired. Better find a repair shop soon!
BRAKE WARNING LIGHT
The Brake Warning light will come on if the parking brake has not been fully released, but it may equally come on if the brake fluid level is low or there has been a loss of hydraulic pressure in one of your car’s brake circuits. Loss of fluid or brake pressure implies the brakes may not be able to stop your vehicle when you step on the pedal.
Carefully apply the brakes to see if they are working. If they are, pull over to the side of the road, open the hood and check the fluid level in the brake master cylinder. If the fluid level is low, the brake system should be checked for leaks. If there are leaks, your brake system is unsafe to drive.
If the brake pedal is low or goes to the floor, pumping the pedal may apply enough pressure to stop your vehicle. If that fails, apply your parking brake to slow your vehicle. Also, take your foot off the gas and shift to neutral, or downshift and use engine braking to slow your car if you have a manual transmission. If all that fails, target for something soft like a bush or open field.
Possible Causes: Loss of brake fluid because of leaks (master cylinder, calipers, wheel cylinders, brake lines or hoses), failure of the pressure differential switch that activates the brake light, parking brake pedal or handle not fully releasing, defective parking brake switch.
WARNING: If the brake pedal feels soft, is low, goes to the floor, or you have to pump the pedal to get your car to stop, your car is unsafe to drive. You should have it towed to a repair facility for repairs.
LOW TIRE WARNING LIGHT
The Low Tire Pressure Warning Light will come on if any tire on your car is 25 percent or more underinflated. Driving on a low tire can be dangerous since it increases the risk of a tire blowout. A low tire can equally cause uneven braking, uneven traction, uneven and rapid tire wear, increased rolling resistance and fuel consumption.
Locate a gas station with an air pump, and inspect the inflation pressure in each tire with an accurate gauge (not the gauge on the pump, which is often very inaccurate!). Include air as required to inflate your tires to the recommended pressure (see your owners manual or the tire inflation decal in teh door jam or glove box). For most passenger vehicle, the recommended pressure is typically 32 to 34 PSI.
Possible Causes: Loss of air pressure because of a leak (such as a nail or small puncture in a tire, or a bad valve stem), loss of air pressure because of seepage (1 to 2 PSI per month loss is normal for many tires), or inaccurate or failing TPMS sensor in tire.
Checking your tires often (at least once a month or before any long road trip) is adviced. Inspect the tires when they are COLD and BEFORE you drive your car as driving creates friction and heats up the tires (creating an increase in the air pressure).