The TPMS (Tire Pressure Monitoring System) sensor light can come on even if your tires are properly inflated due to several reasons beyond low tire pressure. This comprehensive guide will provide you with advanced and critical details to help you understand and address the issue effectively.
Reasons for TPMS Light On but Tires Are Fine
1. Damaged TPMS Sensor
The TPMS sensor in a tire can be damaged during specific conditions, such as tire replacement or improper mount and dismount procedures. This can impair the sensor’s ability to function correctly, causing the TPMS light to illuminate. According to industry experts, the TPMS sensor is particularly vulnerable to damage during the tire replacement process, with a failure rate of up to 3% when proper procedures are not followed.
2. Faulty TPMS Receiver
While less common than sensor failure, the TPMS receiver in a vehicle can also malfunction. This can prevent accurate data from being calculated, leading to the TPMS light coming on regardless of the actual tire pressure. Diagnostic tests performed by mechanics have shown that up to 15% of TPMS-related issues can be attributed to receiver malfunctions.
3. Dead TPMS Sensor Battery
Direct monitoring TPMS systems use sensors with integrated batteries that can eventually fail, stopping the feedback to the car’s TPMS receiver and triggering the warning light. The average lifespan of a TPMS sensor battery is around 5-7 years, but some advanced models can last up to 10 years.
4. Loss of Traction (Indirect TPMS)
Indirect TPMS systems, which use wheel speed sensors to calculate tire pressure, can cause the TPMS light to come on due to a loss of traction. This can be particularly confusing for drivers, as the tires may be properly inflated, but the system is unable to accurately measure the pressure.
5. Cold Weather Conditions
Cold weather can cause the TPMS light to come on due to the contraction of air inside the tire, leading to lower pressure readings. This is a common occurrence, especially in regions with significant temperature fluctuations. Studies have shown that a 10°F (5.6°C) drop in ambient temperature can result in a 1-2 PSI (0.07-0.14 bar) decrease in tire pressure.
6. Recent Tire Rotation or Replacement
The TPMS sensor can be damaged during the tire rotation or replacement process, leading to the TPMS light coming on. This is often due to improper handling or the use of incorrect tools and techniques. Industry data suggests that up to 20% of TPMS-related issues are caused by sensor damage during tire service.
7. Malfunctioning TPMS Sensor
The TPMS sensor itself can malfunction due to various factors, such as wear and tear, low battery power, or the presence of substances other than air or nitrogen in the tire. This can result in inaccurate pressure readings and the TPMS light being illuminated. Manufacturers report a TPMS sensor failure rate of around 2-5% over the lifetime of the vehicle.
8. Forgotten Spare Tire
If the spare tire is not properly checked or calibrated, it can cause the TPMS light to come on. This is because the TPMS system is designed to monitor all the tires, including the spare, and will trigger the warning light if it detects an issue with the spare tire pressure.
What to Do If the TPMS Light Is On but Tire Pressure Is Fine
-
Check the Spare Tire: Ensure the spare tire is properly inflated to the recommended pressure and that the TPMS sensor for the spare is functioning correctly.
-
Reset the TPMS System: Follow the manufacturer’s instructions to reset the TPMS system, which may involve driving at a certain speed for a specified time or using a reset button. This can help the system relearn the tire pressures and clear any false warnings.
-
Replace the TPMS Sensor: If the sensor is damaged or malfunctioning, it may need to be replaced by a professional. The average cost of a TPMS sensor replacement ranges from $50 to $150, depending on the vehicle make and model.
-
Consult a Mechanic: If the issue persists after trying the above steps, it’s best to consult a qualified mechanic to inspect the TPMS system and diagnose the underlying problem. They can use specialized tools and diagnostic software to identify the root cause and provide a suitable solution.
Technical Specifications
Direct TPMS Systems
- Use sensors inside each tire to measure pressure directly
- Sensor batteries typically last around 10 years
Indirect TPMS Systems
- Use wheel speed sensors to calculate pressure indirectly
- Require manual reset after tire inflation or rotation
TPMS Sensor Battery Life
- Typically lasts around 5-7 years
- Some advanced models can last up to 10 years
References
- https://www.youtube.com/watch?v=udFV5thQ3UA
- https://www.reddit.com/r/MechanicAdvice/comments/15mt2kx/what_other_reason_can_low_tire_pressure_warning/
- https://www.kingstoyota.com/how-to-reset-tire-pressure-light-cincinnati-oh.htm
- https://www.swedespeed.com/threads/tire-pressure-monitoring-system-alert-came-on-but-tire-pressure-is-fine-what-do-i-do.638668/
- https://carfromjapan.com/article/car-maintenance/fix-low-tire-pressure-light-tires-fine-issues/