4 Common Reasons of Tire Pressure Warning Light Comes On
Warning lights such as those from TPMS systems that monitor tire pressure can mean trouble. But surprisingly, the TPMS light can come on even when your tires are properly inflated and not punctured by a screw or nail.
Learn the specific reasons why your TPMS light comes on when your tires are actually underinflated, whether you can continue driving, and how to find a faulty TPMS sensor.
Why Your TPMS Light Comes On
There are several reasons why your vehicle’s TPMS light may come on even when each tire has the correct air pressure. Below are some of the most common such cases.
1) Sensor Damage (TPMS Sensor Defect)
Under certain circumstances, the TPMS sensor in your tire can become damaged, impairing its functionality. This is especially likely if such an issue occurs immediately after a tire change, as special assembly and disassembly procedures are required to prevent sensor damage.
2) Sensor Battery Dead
TPMS sensors used in direct monitoring systems use an internal battery for continued use. These batteries generally have a long lifespan, but are prone to failing over time. This causes feedback to no longer be sent to the vehicle’s TPMS receiver, which illuminates the system’s warning light.
3) TPMS Receiver Failure
This is much less common than sensor failure, but it is possible for a vehicle’s TPMS receiver to actually fail, causing it to not receive and calculate air pressure-related data correctly. This anomaly will cause the vehicle’s TPMS light to come on, regardless of the state of the individual tire pressures or the vehicle’s sensors.
4) Loss of Traction (Indirect)
Early indirect monitoring systems were known to have a particularly strange problem. Because these systems relied on using data from wheel speed sensors, a loss of traction could cause the vehicle’s TPMS light to come on. This often caused a lot of confusion for drivers as they tried to work out the cause of such errors.
Is it okay to drive with the TPMS light on?
Yes, you can indeed drive with your vehicle’s TPMS light on. However, this is not recommended unless your tires are inspected by a qualified professional. In most cases, the presence of such a light indicates low tire pressure. However, if your tires are full of air but your tire pressure light won’t turn off, this could be an issue with the sensor/receiver.
In these cases, it is generally safe to continue as necessary until a sensor replacement is scheduled and completed. However, be aware that your vehicle’s ability to detect and report loss of tire pressure will be impaired until the appropriate repairs are made.
This is because the general TPMS warning light will remain illuminated as long as the error persists.
- If an actual loss of pressure occurs, this light will not come back on.
- If you plan to drive with your car’s TPMS light on, we recommend manually checking your vehicle’s tire pressures using a tire pressure gauge.
- If you have any doubts about the condition of your vehicle’s tires, stop driving immediately until the problem is resolved.
How TPMS Works
The general concept of modern TPMS technology is to alert the driver that the vehicle has one or more underinflated tires before those tires become a safety risk. The technology is required for all 2007 and newer vehicles sold in the United States.
Monitoring a vehicle’s tire pressure is done in one of two ways, the first method is called direct monitoring, while some manufacturers use indirect monitoring for the same purpose. Direct Monitoring
Vehicles with direct TPMS rely on a complete set of pressure sensors mounted on the valve stems that correspond to an integrated receiver module. These sensors record and transmit the pressure of each tire in real time and provide this data to the driver continuously.
This type of TPMS unit is typically very accurate and is found in the majority of new cars today.
Indirect Monitoring
Unlike direct TPMS, this type of indirect system does not have independent pressure sensors for each tire. Instead, vehicles with such warning systems rely on the use of the vehicle’s speed sensor to determine relative tire pressures. The theory behind this is that an underinflated tire will rotate at a slightly different speed than a fully inflated tire. This type of system tends to be slightly less accurate than a direct TPMS and is generally less common.
How do I tell which TPMS sensor is bad?
Many drivers wonder how to identify which TPMS sensor in their vehicle is faulty. Luckily, this is relatively easy to determine. Many of today’s modern vehicles have built-in data displays that show a breakdown of the air pressure in each tire as you shift gears. In this case, finding the problem tire or sensor is as easy as reading the display while looking for the highlighted values.
In other cases, you will need a portable TPMS scanner or an automotive diagnostic tool with TPMS reset capabilities to determine which sensor is not providing feedback. Many auto parts stores and vehicle service centers offer such tests for free as a convenience, allowing you to save the expense of purchasing this type of diagnostic tool.
Can I disable a tire pressure monitoring system? While you can probably find plenty of ways online to disable, trick, or bypass your vehicle’s TPMS system, we don’t recommend doing so.
The use of such systems is required by law and helps increase consumer safety. As with any vehicle security system, it’s best to leave your car’s TPMS function alone.
How to Reset the Tire Pressure Light
After determining and correcting the root cause of your vehicle’s TPMS light, the next matter of business involves resetting the light itself. In the majority of cases, this process is far easier than one might expect, and can be completed in minutes. The following are several examples of how to reset a vehicle’s TPMS light.
Toyota Models
The TPMS light on many Toyota vehicles can be reset by accessing their integrated reset button. This procedure is as follows.
1. Turn Key To “ON” Position: First, turn your vehicle’s key to the “ON” position, without starting the engine itself.
2. Locate Reset Button: Next, locate the vehicle’s TPMS reset button. This button is most often found beneath the steering wheel.
3. Hold Reset Button: Finally, you will depress this button, holding it until the vehicle’s TPMS light blinks 3 times. You will then start your vehicle, before letting it idle for a period of 5-10 minutes.
General Motors Models
The vast majority of GM vehicles, especially featuring first-generation TPMS technology, required the use of a calibrated TPMS tool for rest. The following is one of the most common of all GM reset procedures.
1. Depress Key Fob Buttons: To initiate the relearn procedure, depress the lock and unlock buttons on your key fob simultaneously. Hold these buttons for a period of 3-5 seconds.
2. Listen For Honk: If step one is completed correctly, your vehicle’s horn will honk, signaling the beginning of the reset procedure.
3. Relearn Each Tire: You will now use a relearn device to analyze each sensor, beginning at the left-front wheel. Continue around the vehicle in a clockwise pattern while checking each wheel. Upon checking the final tire, your vehicle’s horn will honk twice, signifying the end of the procedure.
Honda Models
The process to reset the TPMS on Honda vehicles differs according to the age of the car.
For 2016 models and newer with a touchscreen display:
1. Go to the home screen
2. Select settings
3. Click TPMS calibration
4. Select “Calibrate”
For older model Honda vehicles without a touchscreen display:
For old Honda models without touch display, use steering wheel buttons and calibrate through these steps:
1. Use the steering wheel buttons: buttons should be located on the left side of the steering wheel.
2. Select Menu
3. Select ‘Customize Setting’
4. Choose TPMS Calibration
5. Click Initialize