What to Do if Your Tire Pressure Warning Light Comes On

What To Do If Your Tire Pressure Warning Light Comes On

During an episode of the television show Home Improvement, the main character, Tim “the Toolman” Taylor, was grilling his wife, Jill, after she told him the engine in their car had died. Apparently the engine was low on oil and failed. When Tim asked if she saw a check engine light on the dashboard, she said yes, it had been on for days. “Why didn’t you say something?” he barked. Jill replied, “I thought it would change colors or start blinking or something when it got really bad.”

Maybe you are the kind of driver that ignores squealing brakes, funny noises coming from the engine compartment, clunks when you drive over bumps, or warning lights on the dashboard light icons display. Or maybe you are the opposite. You are more likely to have a heart palpitation if you see a check engine light. In most cases, there really is no reason for hysteria when a warning light comes on. But those lights are there for a reason, and they shouldn’t be ignored.

That includes your car’s tire pressure warning light. If it comes on, you don’t have to freak out, pull over, and set up signal flares. However, you should not ignore it either. As part of the Tire Pressure Monitoring System (TPMS), this warning light signals the condition of one or more of your tires. And those tires are pretty important – since they are the only thing between your car and the road.

What does the Tire Pressure Monitoring System do and why do I need it?

You know the tires on your car, truck, or SUV are filled with air. And you probably know that the air inside the tires should be at a specific pressure. You might even know how to check the air pressure in your tires and how to add air when the pressure is low. But, did you know that low tire pressure can lead to dangerous driving conditions, including an increase in stopping distance and a decrease in vehicle handling ability?

Low tire pressure is also a leading cause of poor fuel economy and reduces tire tread life. A loss of tire pressure causes additional drag so that the engine needs to work harder to compensate, and leads to premature wear on the tire surface.

Because it is difficult to visually identify a drop of only a few PSI – and because most drivers will not take the time to regularly check the pressure in tires that otherwise look fine – manufacturers are required to include a system to monitor the tire pressure. This often involves sensors located inside the tires (direct TPMS) that read the internal air pressure. These sensors communicate wirelessly with the vehicle’s computer system to let it know when the pressure is low – usually after a 25% drop in pressure from the manufacturer’s recommendation. Some vehicles use the wheel speed sensors in the Antilock Braking System (ABS) to detect changes in wheel speed that may result from a change in tire size due to underinflation (indirect TPMS). In these cases, sensors are not located inside the tires. The ABS calculates the tire pressure.

The computer, in turn, signals you – the driver – to let you know that it is time to add air. That is what the tire pressure warning light is for. On some vehicles, the warning light points out which tire is low, while on others, only the fact that a tire is low is indicated.

Of course, if your tire is more than low – if it is going flat because you ran over something – the TPMS will sense that as well. So, the system will alert you if you have an urgent problem to attend to, or if the pressure has dropped because of a slow leak, a change in air temperature, or even a normal pressure drop because tires do not seal perfectly.

What do I do if the tire pressure warning light comes on?

If the tire pressure warning light comes on, either when you are driving or when you start your car, and it remains steadily lit, you need to add air to one or more of your tires. If your dashboard does not tell you which tire is low, check all four tires with a tire pressure gauge. Check the spare tire as well. If your vehicle has a full-size spare tire, it is likely that it also includes a TPMS sensor. And because the spare tire is often neglected, it commonly loses pressure over time.

Once you locate the low tire, locate also the vehicle manufacturer’s recommendation for tire pressure. This information can be found on a tag inside the driver’s door jamb or in your owner’s manual. The pressure specification printed on the tire is the maximum pressure the tire can hold safely. It is not the vehicle manufacturer’s recommendation. Do not fill to the amount listed on the tire; use the vehicle manufacturer’s specification. Add air using an air compressor and recheck the pressure with the tire pressure gauge. The tire pressure warning light should go off a few minutes after you add air. If it does not (or if your vehicle has indirect TPMS), you might need to have the computer reset at a repair shop.

What if the light is blinking?

Normally, the tire pressure warning light will remain steadily lit until the low tire is filled to the recommended pressure. If, on the other hand, it blinks repeatedly, the problem is likely to be one or more of the TPMS sensors, not the tire pressure. The batteries inside the sensors (direct TPMS) are designed to last about a decade before needing to be replaced. Sensors can also go bad. They are also susceptible to damage during tire installation. If your tire pressure warning light is on and stays on – add air to your tire(s). If it is blinking, take your vehicle in for service to have the batteries or sensors replaced.

What other tire services are available?

If you are not comfortable with servicing your tires yourself, feel free to take your car in to a qualified repair shop. In addition to checking your tire pressure, adding air to your tires, and resetting your TPMS sensors, they can also can assist you with other tire-related services. These services might include tire repair for leaks due to some punctures, tire rotation to ensure even tire wear, and tread wear inspection to determine when you might need new tires. If your tires are worn out, they can provide tire replacement and wheel balancing. And if your tires are wearing unevenly, they can perform a wheel alignment.

Correct tire pressure is enough of a concern that the federal government mandated that all new cars include a Tire Pressure Monitoring System. If your tire pressure warning light comes on, don’t neglect it. Fill ‘em up – or see the pros at Hogan & Sons Tire and Auto ] to have your tires inspected and serviced.


This article is intended only as a general guidance document and relying on its material is at your sole risk. By using this general guidance document, you agree to defend, indemnify and hold harmless Hogan & Sons Tire and Auto and its affiliates from and against any and all claims, damages, costs and expenses, including attorneys’ fees, arising from or related to your use of this guidance document. To the extent fully permissible under applicable law, Hogan & Sons Tire and Auto makes no representations or warranties of any kind, express or implied, as to the information, content, or materials included in this

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