Over the years at my repair shop, I’ve seen countless cases where a glitchy low-pressure warning signal left drivers vulnerable without them knowing. So, testing it occasionally is more of a necessity than a choice.
But how can you test the low-pressure warning signal in your vehicle? Well, it’s not that hard when the battery is charged up well. All you need to do is turn off the engine with enough air pressure before applying the brake and releasing it in quick succession.
This should trigger the signal before the air pressure drops below 60 psi. Let’s explore more on this whole low-pressure warning thing and how you can test it accurately.
What Is Low-Pressure Warning Signal?
The low-pressure warning signal is a crucial safety feature in modern vehicles designed to alert you whenever your vehicle’s air brake system has a huge drop in pneumatic pressure.
You can locate the warning sign among the other notifiers on your car’s dashboard. It looks something like the picture below.
The warning sign automatically starts blinking in yellow or amber when the air pressure falls below a specific level. Typically, it’s around 60 psi in most vehicles, but it’ll depend on how it’s specified in your particular model and year.
With the blinking, the signal tells you when to pull over and inspect the air pressure somewhere safe so you can avoid potential mishaps while on the road. After all, when your tires are under-inflated, you never know when it’ll blow out.
Different Types of Low Air Pressure Warning Signals
Tire pressure monitoring systems, or TPMs became quite the norm during the 2000s, and the US government required all new cars to have this since 2008. There are three main types: direct TPMS, valve stem direct TPMs, and indirect TPMS, which alert differently.
Direct TPMs use a sensor inside the vehicle tires to monitor air pressure in each. If your car has its stems held at its base with nuts, the tires likely have these sensors installed.
These sensors continuously detect the pressure levels and send the data to the computer. The computer system then blinks the warning light if the levels are lower than the minimum specified by your car’s manufacturers.
Valve Stem Direct TPMs
These TPMs are similar to Direct TPMs, and they trigger the low-pressure warning light on your car’s dashboard the same way as well.
The only difference between them is where they’re located. Whereas direct TPMs are nestled within the tire, the valve stem direct TPMs are fixed directly to the car’s valve stem.
As external modules, they offer quick and accurate pressure readings. However, you may need to replace them more frequently than direct TPMs as they’re damaged easily.
The Indirect Tire Pressure Monitoring Systems (TPMS) don’t actually station sensors within your tires. Instead, they use the car’s ABS (Anti-Lock Brake System) wheel speed sensors.
These sensors act quickly to detect whenever one tire is rotating faster than the others, signifying a potential low-pressure problem. If it finds any discrepancy in speed, it alerts the warning sign on your dashboard.
But the problem with these systems is that it’s hard to know if your tires are low in pressure when they all lose pressure equally and rotate at the same speed.
What Are the Causes of Low-Pressure Warning Signals?
As the TPMs only trigger when the air pressure in your tires is low, the warning signal on your dashboard can possibly start flashing when you have:
- Underinflated tires
- Slow leaks in tires
- Change in the surrounding temperature
- Damaged tire sensors
- Faulty brake system
- Problems with the TPMS itself, like sensor battery failure
How Do You Test the Low-Pressure Warning Signal in Vehicles?
Like I’ve said already, it’s essential to test your car’s low-pressure warning signal even when you think it’s working fine. I’ve encountered several cases where the car owner thought the tires had enough air while they didn’t, and the misunderstanding resulted in fatal accidents.
Here’s how you can test if your low-pressure signal warning system detects the pressure accurately.
Step 1: Determine Your Car’s Recommended Tire Pressure
Finding your car’s recommended tire pressure shouldn’t be hard at all if you just look around your car. In most vehicles, the door jamb has an indicator sticker specifying the ideal pressure.
However, if yours hasn’t somehow, you can also check the owner’s manual. Once you find it, take note of the minimum recommended pressure, which is typically 60 psi.
Step 2: Ensure Enough Air Pressure in the Tires
If you find your tires are underinflated, you’ll need to fill it up. However, it needn’t be full. Since your goal is only to test if the sensors are working, just over the minimum recommended pressure will do.
But be sure to check the pressure with a good tire pressure gauge. Also, start your car and check to confirm the warning light isn’t blinking.
Step 3: Apply the Brake Pedal and Release It Quickly
Turn the engine off while there’s enough pressure. Then turn on the electric power and release air by applying and releasing the brake in quick succession. Be attentive to your pressure gauge and stop releasing air once it goes below 60 psi or the minimum needed for your tires.
The warning sign must have been triggered at this point. If it didn’t, there might be an issue with the sensor.
What To Do if You are Getting Low-Pressure Warning Signals Frequently?
When it comes to avoiding low-pressure warnings, it’s all about keeping an eye on your tires to see if they’re filled up as they should. So, here are some things I’d suggest you to maintain the right tire pressure and keep the warning signal off:
- Regularly check the air pressure in your tires
- Check for damages in the pressure valves
- Look out for nails, screws, or any sharp objects stuck in the tire
- Replace worn-out or damaged tires
- Always put in the correct amount of air when inflating your tires
- Always ensure your tire pressure sensors are working correctly
- Avoid overloading your vehicle, as this can lead to a drop in tire pressure
- Use a high-quality pressure gauge and ensure it’s calibrated correctly
- Regularly check the TPMS battery and replace it when needed
- Watch for sharp corners, potholes, and raised curbs to reduce wear and tear
Frequently Asked Questions
Have you got further queries about low-pressure warning signals? Here, I’ve answered a few questions that might help.
How long can you drive with low-pressure warning signals?
I’d advise not driving at all when you’ve got tires low in air pressure. It can lead to premature wear, poor fuel economy, and even blowouts. If you see a low-pressure warning, it’s best to pull over and fill it up as soon as you can.
What happens if you ignore a low-pressure warning signal?
Ignoring a low-pressure warning signal can be dangerous. When your tires are underinflated, they are in more direct contact with the road’s surface, which can overheat them and lead to a sudden blowout. The risks increase if you’re driving at high speeds.
Does the low-pressure warning signal indicate which tire is underinflated?
Not all the TPMS systems can do this. Most only display a general warning when any one of the tires is low in pressure, but some advanced connected car systems can show you the tire pressure readings of each wheel. It totally depends on your car and what system it’s running.
So, that’s that. If you were searching for the perfect answer to how can you test the low-pressure warning signal, you have it now.
As TPMs are electrical components, they can get glitchy at times, leaving you fully oblivious to when it’s got low in pressure and risking your safety.
Hence, for your own peace of mind and of course, safety, keeping a regular check on the functioning of these systems is ever so crucial.