The TPMS light alerts the vehicle driver of low tire pressure and keeps you safe on the road. However, there are times when the sensors or system malfunction and cause the low tire pressure light to engage when the tires are fine. So, what causes this issue? What to do?
We explore all of the causes explored in-depth in this guide. We also consider the differences between the various types of TPMS systems and ways to desensitize the light. Finally, we answer whether it is safe to continue driving with that TPMS light on.
Causes of Low Tire Pressure Light is On with Correct Tire Pressure
If your low tire pressure light is lit, even though the tire pressure is fine, you may need to reset the TPMS. If there has been no reset, it can also be due to an issue with the TPMS sensor.
Additionally, the sensor battery could also be dead, or the TPMS receiver could potentially be damaged. If you have an indirect TPMS system, it could even be the loss of traction.
Here is some more detail about possible causes of a low tire pressure light being on while tire pressure being good.
#1. Faulty or Unprogrammed Tire Pressure Sensor.
If you corrected the tire pressure but the TPMS light still remains on, you will need to reset the TPMS system, either with a scanner or check your car for a method for resetting the TPMS system.
At times the tire pressure sensors lose the programmed data, so you may need to reset the TPMS sensor using the OBD2 scanner or TPMS Reset tool if you verified all else involves tire pressure and performance are working correctly.
The TPMS sensor can also be easy damaged and keep the light on. The downside of a damaged sensor is it is not monitoring the tire pressures for you and put your health and safety at risk.
The sensor can be damaged by debris or contaminants. It can also be damaged mounting and dismounting tires, which takes extra care to make sure the sensor is protected during the tire change.
#2. Dead Battery in Sensor.
Direct monitoring TPMS sensors require batteries to function normally. Although the batteries are designed for long use, they can and will fail. On average, they may fail every five to ten years.
When a battery fails there can’t be any feedback through the system. This means they light will come on because there is not communication.
#3. Defective TPMS Receiver.
While this is less common than the other two examples, it can occur. The TPMS receiver may fail and no longer obtain pressure data from the tires.
There is no rhyme or reason to why this happens occasionally. An electronic device can fail to operate properly, so regardless of the pressure in each tire, the warning will illuminate.
#4. Traction Loss.
If you have an indirect TPMS, it can activate the warning light if you begin losing traction. The TPMS uses the wheel speed sensor information to determine when to trigger a low tire pressure warning.
When you lose traction, the TPMS may assume a tire is losing pressure even though it is not. This can lead to confusion, especially when the TPMS warning light has come on and gone off a few times.
Understanding Direct vs. Indirect TPMS
#1. Direct.
The direct TPMS is used in most cars on the road today. With this design, all four wheels have a sensor that feeds information back to the computer. If the tire pressure gets low, a signal is sent and the alert comes on the dashboard.
Because of where the sensors are located, there can be damage to them when driving on harsh road conditions, such as dirt driveways or during service. They also go bad simply because of old age, requiring replacement over time.
#2. Indirect.
Some manufacturers prefer the indirect system, which doesn’t use a sensor on each wheel. Instead, the TPMS runs from the sensors on the anti-lock brakes. These sensors determine when the rotation speed is slow, indicating that tire pressure might be low.
The indirect TPMS is considered more durable than the normal system because it doesn’t fail as often. However, you aren’t going to know if multiple tires are running low since there aren’t separate sensors.
Up until now, it’s only been some Asian and European automakers that have chosen this TPMS configuration. However, other automakers are discussing switching over, making it more of a standard option across the board.
How to Fix TPMS Light?
#1. Inflate the Tire.
The first solution is to inflate the low tire properly. The light will come on, and you should always check the tire pressures first.
You can compare the reading with the recommended air pressure on the driver’s side door jamb. If the light stays on, and the pressures are correct, you will have to go to our other tips.
#2. Repair the Fault.
The repair that you carry out will depend on what fault is being caused. If you do not have the tools to figure out what is wrong, you should take the car to a professional.
A simple TPMS sensor can cost $75 to $250 to replace, which includes the sensor and labor. A dead battery usually means that a new sensor is also needed. If the receiver is required to be changed, the cost will be slightly higher.
If you have the tools and knowledge to change the sensor and receiver, you can repair this yourself and charge only for the parts and not for the labor.
#3. Reset the Light.
If the light has come on because there was a fault after rotating the tires or servicing, you may need to reset the light. Most car makers have an easy way to reset the warning light. You will find the details in the owner’s manual.
There may be a reset button in the glove box or in the car system menu settings. Additionally, you need to know how long to hold the button and what exact steps to take to reset the light.
Can I Drive with the TPMS Light On?
You should react to a TPMS light warning if it appears on the dashboard. Your first consideration should be to pull over quick to check proper air pressure in the tires. If the tire is not inflated correctly, they could fail.
When tire is under inflating the tire could overheat and burst creating an unsafe situation. If you are not aware that the tire pressure is continuously losing air you lose control. At a minimum the tire is uneven wear, causing a friction, and the need for a new tire or tires sooner.
When the Tire Pressure Monitoring System lights up and all the tires are perfectly inflated you still would never know if there was a problem. Things such as a bad sensor ignoring it until it was too late, and instead of having tires inflated 32 psi, one could be 25 psi, creating a greater risk until it gets lower and possibly resulting a accident.
As the tires get lower, you start to deal with:
- Delayed driving response
- Additional wear to the tires
- Overheating tires
- Reduced traction
- Bumpier ride
- Less on-road control
The cost of getting the air or fixing the problem isn’t even close to the risk. You will pay a fraction for the repair compared to what liability you may face in the event of a significant crash.
Plus, a bad crash could turn someone’s life around if there are injuries. Is this really worth ignoring the helpful TPMS light?