An alert pops up on your dashboard and you feel a sinking sensation in your gut. The first step – before you start to stress out: Check the color. That quick detail can clue you in on whether you’re dealing with a minor issue or a full-on emergency.
Green and blue lights are purely informational. Yellow and orange ones are warnings that something is wrong or about to go wrong. Red lights mean come to a stop right this second and turn off the engine.
What The Light Is Doing Matters Just As Much As Which Light It Is
Once you’ve made a mental note of the color, sit back and study the behavior. A light can stay steadily illuminated or it can flash furiously. And that discrepancy can cost you hundreds or even thousands of dollars if you ignore it.
For instance, a solid check engine light generally means your car’s OBD-II system has detected a fault and most likely something you should get checked soon, but you should be able to continue driving to your destination or directly to a mechanic. A flashing check engine light means an active engine misfire – get off the road or head to the closest parking lot as soon as you can pull over. You’re quite possibly doing expensive damage to your catalytic converter right now.
The same goes for the oil pressure warning light. If you’re driving and the red oil can light comes on, you could be making a choice between hundreds of dollars of engine bearings or a few bucks of oil. A temperature gauge well in the red has similar immediacy. Head gasket repair from an overheated engine is one of the more prohibitively expensive fixes your car can need.
How To Execute A Controlled Stop
Pulling over may seem like something that doesn’t need to be considered, but there’s a safe way to do it, and it’s worth knowing a couple of simple rules.
Signal early and move right as smoothly as you can to the shoulder, or preferably a parking lot or side street well clear of the active traffic lanes. Once you come to a halt, turn your hazard lights on immediately. If you have road flares or warning triangles, use them – and put them some distance back along the road, not just a few feet behind your car where following drivers may not see them.
Don’t leave the car until you’re certain it’s stable and you’re in a place where other drivers can spot you. A wide, well-lighted shoulder is a reasonable refuge. A narrow lane on a dark, wet, blind curve is not.
Once stopped, do a very quick visual. Do you see fluid pouring out from under the car, smoke or a seriously flat tire? The TPMS light will often tell you if it’s just a flat, but taking a quick look is a thirty-second job and sometimes that light will be warning you about something more immediate. What you should not do is open the radiator cap on an overheated engine: coolant will spray out, and if any gets on you, it will stick to you until it evaporates – leaving you with a serious burn.
Deciding Whether To Drive Or Call
This decision often determines whether drivers save or lose a lot of money.
If the light is yellow and the car is “normal” – no strange mechanical noises, no dramatic performance loss, no warning from a backup system – driving carefully to a nearby repair shop is a rational choice. Ideally, have the car scanned for Diagnostic Trouble Codes within a day or two, but you’re likely not adding a four-figure repair to your bill by driving a little further.
If the car is in limp mode, if a warning light is accompanied by perceptible abnormal driving behavior, or if two lights are on at once, the car is telling you that it’s trying to handle a really bad fault or faults. Limp mode isn’t a subtle hint that you should eventually park the car and give the key to your mechanic. It’s the car computer’s best effort to preserve the engine despite the fact that the wheels are still going around. Red light, white knuckles should mean towing, as towing is cheaper than repairs that result from driving a zombie car.
Contacting professional roadside assistance services is the right move – not because it’s convenient, but because it stops the damage from compounding.
The Brake And Charging System Are Separate Cases
There are two warning lights in particular that demand your immediate attention because neither one leaves you with much margin of error.
The brake system warning light – as opposed to the parking brake indicator – can be telling you that you’re low on fluid or that some mechanical part of the vehicle’s braking system has failed. Your safety is not something debatable.
The other one is the battery or alternator light, signaling that the vehicle is no longer charging the battery. The car should keep running (for a while) on the battery power that remains, but once it’s used up, it’s all over; there will be no more juice and you won’t even be able to restart the engine. You’ve got maybe ten minutes, maybe forty, and nobody can tell you which.
In either of these cases, you pull over when it’s safe and you do not drive the car until somebody competent has had a look at it.
When the warning light comes on, the sequence is simple: you read the color, you observe the behavior, you find a place to stop, you look at what you can see, you make a simple and unemotional decision about how you will proceed. Panic isn’t part of the equation.