TPWS Malfunction Toyota (Here Is How To Fix)


TPWS Malfunction

There is a whole array of different warning lights and error messages that can appear on your dashboard and completely ruin your day, but what do you actually need to do when one lights up? If you’ve been experiencing a TPWS malfunction, then we’ve got the solution.

TPWS stands for Tire Pressure Warning System, which is designed to let you know that the air pressure in your tires is not at a safe and efficient level. This system can activate in error, though, and may need resetting or even repairing to remove the warning.

Here are a few steps you need to take to fix a TPWS malfunction, especially on Toyota vehicles:

Step 1: Allow the system to recalibrate

Step 2: Turn the TPMS off and on again

Step 3: Refresh the air in your tires

Step 4: Reset all the electronics

Step 5: Check the sensors

Step 6: Call in the professionals

What Does TPWS Mean?

Before we get into how to solve any issues that you might find with this particular feature in your car, we first need to identify what it actually is and what it does.

TPWS is an acronym that is only really used by specific models of Toyota, and it stands for Tire Pressure Warning System.

In many other vehicles, it is instead referred to as the TPMS – or the Tire Pressure Monitoring System. It may seem confusing, but they are just different terms for the same thing.

Your TPWS monitors the air pressure in your tires and gives you an indication to warn you when this pressure is not at the right level for optimum driving performance. Basically, the TPWS uses either direct or indirect sensors to read the level of pressure and flags an alert when the pressure changes from what it should be.

  • Direct TPWS: This is when there is an air pressure sensor in each wheel, located on the valve of the tire. They can give readings in real-time for pressure and temperature, and these readings are more accurate. The sensors are, however, more susceptible to damage during maintenance and tire changes.
  • Indirect TPWS: This system uses the ABS wheel speed sensors to monitor how each wheel’s speed is changing. If one tire is rotating faster than the others, this indicates that it is underinflated. Indirect TPWS is cheaper, but it needs to be reset after tire maintenance and is less accurate overall.

Read also >> BMW TPM Malfunction: Here Is How To Fix (Step by Step Guide)

Why Is Tire Pressure Important?

So why does this system exist and should you be worried if the warning light turns on? Well, having the correct tire pressure is not only hugely beneficial for fuel efficiency and overall performance, but it is also a pretty significant safety concern as well.

If your tires are underinflated, then they will have an impact on a number of different aspects of the normal functioning of your vehicle, including:

  • Poor traction on the road surface
  • Increased braking distances
  • Less responsive steering and handling
  • Higher rolling resistance, reducing fuel economy
  • More wear on the outer edges, requiring more frequent replacements and a higher risk of blowouts
  • Generating more heat, leading to tread loss and a higher risk of blowouts

On the other hand, it is also possible for your tires to be overinflated, although this is less of a risk and less likely in modern vehicles due to their ability to withstand pressures in excess of what is needed.

With that being said, regularly overinflated tires can cause more wear on the central tread, meaning they need to be replaced more often.

Fortunately, it’s very easy to keep an eye on the pressure in your tires and you can top them up at pretty much any gas station for just a couple of dollars.

How To Fix TPWS Malfunction

If you have checked the air pressure in your tires and everything seems to be perfectly fine, then there is probably an issue with the Tire Pressure Warning System itself. This is actually a pretty common complaint, in many different makes and models of vehicles, where the light seems to turn on for no particular reason.

To solve this issue, we’ve put together a simple step-by-step guide for everything that you might need to do to first reset the TPWS and, if this doesn’t solve the problem, what you can try next.

Step 1: Allow the system to recalibrate

If you have checked and you are sure that the air pressure in your tires is normal, then you can try driving it for a short period to allow the TPWS to reset.

To calibrate the system, it usually takes around 30 minutes of cumulative driving at between 30 and 65 mph.

Step 2: Turn the TPMS off and on again

It’s a classic fix, but it works more often than it doesn’t. With the car safely parked and switched off, turn the key to the “on” position but don’t actually start it up.

Then, press and hold the TPWS button (usually located under the steering wheel) until the pressure light flashes three times, then release it.

Now, simply start up the car and wait for around 10 to 20 minutes for the sensors to reset.

Step 3: Refresh the air in your tires

Another way to reset the system is to very slightly overinflate the tires, by around 3 PSI more than what is recommended, then completely deflate them, then fully reinflate them back to the recommended amount of pressure.

Step 4: Reset all the electronics

If these methods don’t work, then you can try resetting all of the electronics in the vehicle by disconnecting the battery while the car is switched off, waiting for around 10 minutes, then reconnecting it and starting the car up again.

Step 5: Check the sensors

If resetting the TPWS doesn’t work, then you might want to have a look at the sensors themselves.

Direct TPWS sensors are usually located in the space between the tire and the wheel trim, and they can become damaged or obstructed by dirt, debris, or something like a sealant.

Giving the sensors a clean might be all that you need to do, but they may also need repairing or replacing.

Step 6: Call in the professionals

If you’ve tried everything else, then the problem is likely caused by damage to the system, or you need the entire TPWS to be re-initialized.

Both of these jobs are best left to the professionals, and it usually costs a pretty reasonable amount to get them done.

A professional reset of your TPWS will usually set you back between $30 and $40, and repairs and replacements typically range from $50 to $100.

Why Is The TPWS Light On?

Now that we know why you need to keep an eye on your tire pressure, we can talk about what that little light is actually telling you.

Remember: its job is to indicate when the tire pressure has changed from what is optimal, but this can mean a few different things.

A Tire Is Underinflated

If you have just put air into your tires, made a replacement, or carried out some regular maintenance then it might simply be that the tire does not have enough air in it.

You can check the exact tire pressure yourself using a quality pressure gauge, which only costs around $10-$20 to purchase.

You Have Installed New Tires

You might assume that new tires are always going to be at their best, but installing one is actually when they are most likely to experience a flat or some other issue. If the warning light is on, then it’s worth investigating.

On the other hand, some TPWS systems have different configurations for different tire sizes, so they can malfunction and read the pressure incorrectly if you install tires that are not within the manufacturer’s recommendations.

You Have A Flat Tire

The light will also come on when you have a flat, as the sensor will register that the tire has lost almost all of its pressure.

This one is often easy to spot as you might notice a significant change in how the vehicle is driving. Make sure to slowly and safely pull over if a flat occurs while you’re on the road, and install a replacement tire before driving away.

Sometimes, a flat might not be visible so you should also use your tire gauge to check the pressure in each tire – even if they look perfectly normal.

The Temperature Has Changed

Air expands when it is hot and contracts when it is cool, so seasonal temperature changes will affect the air pressure in your tires. It doesn’t mean that air has escaped, but you may need to top them up anyway if they are all registering as too low.

You should reset your tire pressure at the beginning of the summer and at the beginning of winter, to prepare for this change.

The TPWS Has A Malfunction

If none of the above is true, then it might well be that the system is sending you the warning when it doesn’t need to, and you have a genuine malfunction with your TPWS.

Toyota TPWS Malfunction FAQs

How Long Can I Drive With TPWS Light On?

Depending on the exact problem, you may be able to drive for a while with your TPWS light on, or it may very quickly become highly dangerous to do so.

It is always best to pull over as soon as possible and check the air pressure on every tire to make sure you are not driving with a flat, or you could experience a blowout at high speeds.

Is A TPWS Warning Light An MOT Failure?

If you’re getting your MOT done in the UK, having the TPWS warning light on can be an instant failure as it could indicate that there is a potential fault with the valves or sensors.

It’s best to resolve this problem before you take your vehicle in for an inspection.

Why Is My Tire Pressure Light On When My Tires Are Fine?

If you are sure that your tires are fine but the TPWS warning light is still on, then this may be due to temperature changes, incompatible tire sizes, or a malfunction in the TPWS system.

Summary

So, what is a TPWS malfunction and what do you need to do about it? The Tire Pressure Warning System is designed to tell you when the air pressure in your tires is outside of its recommended range, which can be dangerous and lower your vehicle’s performance.

If the light is on and your tire pressure is normal, then it might be because of a malfunction in the system.

You can try resetting the TPWS in various ways, inspecting the sensors, or taking it in for a repair or full re-initialization.

References

https://www.goodyear.eu/en_gb/consumer/learn/what-is-tpms.html

https://www.aaa.com/autorepair/articles/the-importance-of-proper-tire-inflation

Steve P.

Steve is an automotive technician, technical writer, and Managing Editor. He has held a lifelong passion for cars, with a particular interest in cars like the Buick Riviera. Steve is based in Boise, Idaho.

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