Can You Pass Emissions With Tire Pressure Light On? [ Answered ]

For car owners, passing the emission tests is a major concern. You cannot get your car’s registration renewed unless it passes the annual emissions test.

While your car should be able to pass the test as long as you take proper care of it, things don’t always go as planned. During the test, the tires should have enough stability and pressure. Unless your tire pressure meets the standards, the test won’t even take place.

Can you pass emissions with tire pressure light on?

The TPMS (Tire Pressure Measuring System) is an extremely useful piece of equipment that provides real-time information about the pressure in the tires.

In case of low tire pressure, you would receive an alert from the TPMS indicator light. However, at times, the TPMS can go faulty and turn on the low-pressure indicator due to errors.

This can potentially prove to be a hurdle when getting your car emission tested. Thankfully, you don’t have to worry about your car failing the emission tests because of the TPMS light, as long as the tires actually have enough pressure.

In many European countries, cars fail emission tests if the TPMS light is on. However, this isn’t the case in the US. In case your tires have enough pressure and meet the standards, the technicians simply carry on with the test even if the TPMS light is on.

Hence, in case your car has an old TPMS that’s starting to wear out and turns on even when your tires have enough air, you need not worry.

If the TPMS correctly detects low tire pressure, the smog technicians would usually add the necessary air and go ahead with the test. They might even refuse to inspect the car under severe conditions.

You can then get the tires refilled properly and take the car back for testing. In any case, you need not feel concerned about potentially failing the emission test due to the TPMS light.

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Statewide TPMS vehicle inspection requirements in the USA

Different states in the US have their own vehicle laws and regulations. Hence, regulations regarding TPMS vehicle inspection requirements vary from one state to another. In some of the states, your TPMS needs to work seamlessly to help your vehicle clear the inspection. In others, it doesn’t matter. Here’s a quick overview of the laws in different states:

Delaware: It doesn’t matter, your vehicle can still pass the test even if the TPMS isn’t working.
Hawaii: Your TPMS needs to be functional and working properly.
Louisiana: It doesn’t matter, your vehicle can still pass the test even if the TPMS isn’t working.
Maine: It doesn’t matter, your vehicle can still pass the test even if the TPMS isn’t working.
Massachusetts: It doesn’t matter, your vehicle can still pass the test even if the TPMS isn’t working.
Mississippi: It doesn’t matter, your vehicle can still pass the test even if the TPMS isn’t working.
Missouri: It doesn’t matter, your vehicle can still pass the test even if the TPMS isn’t working.
New Hampshire: It doesn’t matter, your vehicle can still pass the test even if the TPMS isn’t working.
New Jersey: It doesn’t matter, your vehicle can still pass the test even if the TPMS isn’t working.
New York: The TPMS undergoes inspection too, but your car won’t fail the test if it’s faulty.
North Carolina: It doesn’t matter, your vehicle can still pass the test even if the TPMS isn’t working.
Pennsylvania: It doesn’t matter, your vehicle can still pass the test even if the TPMS isn’t working.
Rhode Island: Your TPMS needs to be functional and working properly.
Texas: It doesn’t matter, your vehicle can still pass the test even if the TPMS isn’t working.
Utah: It doesn’t matter, your vehicle can still pass the test even if the TPMS isn’t working.
Vermont: Your TPMS needs to be functional and working properly.
Virginia: It doesn’t matter, your vehicle can still pass the test even if the TPMS isn’t working.
West Virginia: Your TPMS needs to be functional and working properly.

Hence, depending on where you live, you may have to get your faulty TPMS fixed before taking your car for inspection. It isn’t uncommon for the TPMS components to go faulty, especially when your car grows old and it starts wearing out.

Does tire pressure sensor affect inspection?

As tire pressure is not a crucial emission or safety feature on a car, your tire pressure sensor won’t affect the inspection much.

Unless your tires are actually in a bad condition and pose a hazard, their pressure shouldn’t be an issue. The inspection technicians focus on more important factors, such as the toxicity level of the emissions and potential safety concerns.

Can I drive with check tire pressure light on?

Your TPMS can’t stop the car, it only warns you of low tire pressure. Hence, you can still drive the car with the tire pressure light on.

However, just because it’s possible to drive a car with its TPMS light on doesn’t mean you should. Unless your TPMS is faulty and your tires have enough pressure, it is a bad idea to keep driving for much longer without refilling them.

There is a reason why your car has a tire pressure measurement system in the first place – it’s unsafe to drive with underinflated tires. As your tires lose pressure, the car starts lacking control and stability.

This increases the risk of a crash, while lowering the vehicle’s performance. If your TPMS is working fine and the light turns on, you should drive to an air pump and get the tires refilled immediately.

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Ways to turn off the TPMS light before the inspection?

Provided that your TPMS is fully functional, the best way to turn off the light is to simply reinflate your tires. The TPMS light should turn off when there is enough pressure. If it doesn’t turn off, an easy fix is to drive the car for about ten minutes at 50 mph. In case the problem continues to bother you, try these measures.

First, overinflate all the tires with 3 PSI, and then deflate them entirely. Now inflate them once again, it should reset the light.
The TPMS has a reset button. Turn the car on with the key, but don’t actually start it. Press the TPMS button and hold it until the tire pressure light blinks thrice. Let go of the button and start driving. The light would usually turn off after running the car for 20 minutes.
Turn off the vehicle and disconnect the positive battery cable. Now turn the car back on and discharge the remaining power by pressing the horn for three seconds. Now connect the battery again and find out if the tire pressure light has turned off.

If none of these methods work, you may take your car to a service center and get the TPMS fixed by a professional. It’s a good idea to repair a faulty TPMS anyway, because if the light stays on at all times, it’ll be impossible to notice when the tire pressure is actually low.

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Conclusion

While driving with low tire pressure is unsafe, your TPMS light won’t cause your car to fail emissions. At most, you may have to get the tires pumped to the necessary pressure level before the vehicle can undergo the test.

However, if your TPMS is faulty, it may stop you from passing the emissions and safety tests depending on your state. Regardless, it’s a good idea to fix a bad TPMS anyway, regardless of the regulations in your state.

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