A tire pressure monitor fault means your vehicle's sensor system has detected a problem — either a faulty sensor, a dead battery in the sensor, or a wiring issue — rather than low tire pressure itself
Your tire pressure monitoring system (TPMS) uses small sensors mounted inside or on each wheel to measure air pressure and send that data to your dashboard. When the system detects a problem with a sensor or its connection, it displays a fault message instead of a pressure reading. This is different from the standard low-pressure warning, which means your tires actually need air.
A fault message tells you the monitoring system itself is broken, not necessarily your tires. You still need to check your tire pressure manually — with a tire gauge — because the system cannot do it for you right now. The fault could be a single bad sensor, corrosion in the wiring, or a sensor battery that has died.
Key Takeaways
- A tire pressure monitor fault means the sensor system is malfunctioning, not that your tires are low on air — check pressure manually with a gauge.
- The most common cause is a dead sensor battery, which typically lasts 5 to 10 years and cannot be replaced separately.
- A single faulty sensor usually costs $150 to $300 to replace at a tire shop or dealership, depending on your vehicle.
- You can drive safely with a fault message as long as you monitor tire pressure yourself until the sensor is repaired.
- Some vehicles display a fault only when the system detects an actual malfunction; others show it when the system cannot communicate with one or more sensors.
Why the sensor battery dies and what happens next
TPMS sensors run on small coin-cell batteries that last between 5 and 10 years, depending on the sensor brand and how often the system transmits data. Once the battery dies, the sensor stops sending pressure readings to your vehicle's computer, and the fault message appears on your dashboard.
When a sensor battery dies, you have two options: replace the entire sensor unit (the standard repair), or have a technician reprogram your vehicle to ignore the dead sensor. Replacing the sensor is more common and costs less over time, because ignoring a sensor leaves you without monitoring on that wheel. A tire shop or dealership can replace one sensor in about 30 minutes to an hour.
If multiple sensors fail at once — which is rare but can happen if your vehicle is older — you may want to replace all four at the same time. This costs more upfront but saves you from returning to the shop repeatedly as the other batteries age.
Corrosion and wiring problems that trigger a fault
Moisture and road salt can corrode the wiring connections between your sensors and the vehicle's receiver module, especially if you live in a cold climate or near the ocean. Corrosion breaks the signal, and your vehicle interprets this as a sensor malfunction.
A technician can sometimes clean the corroded connection and restore the signal without replacing the sensor. This is cheaper than a full sensor replacement — usually $50 to $100 in labor — but the corrosion may return if the connection is not sealed properly. If cleaning does not work, the sensor itself may need replacement.
Wiring damage from a recent tire repair or wheel replacement can also cause a fault. If you had a flat tire fixed or new tires installed shortly before the fault appeared, ask the shop whether they may have disturbed a sensor wire during the work.
How to check your tire pressure while the sensor is broken
Until your sensor is repaired, use a manual tire gauge to check pressure at least once a week. You can buy a digital or dial gauge at any auto parts store for $10 to $25. Check pressure when the tires are cold — before you have driven, or at least three hours after driving — because heat raises pressure and gives a false high reading.
Your vehicle's correct tire pressure is printed on a sticker inside the driver's door jamb, not on the tire sidewall itself. The sidewall number is the maximum pressure the tire can hold, which is different. Write down the correct pressure and compare it to your gauge reading on each wheel.
If any tire is more than 3 pounds per square inch (psi) below the recommended pressure, add air at a gas station or tire shop. If a tire loses pressure repeatedly over a few days, you may have a slow leak that needs repair separate from the sensor fault.
Sensor replacement costs and where to get it done
A single TPMS sensor replacement typically costs $150 to $300 total at a tire shop or dealership, including the sensor itself and labor. The sensor alone costs $40 to $100, and labor is usually $50 to $150 depending on how straightforward the sensor is to access on your vehicle.
Some vehicles have sensors mounted on the wheel valve stem, which are easier to replace. Others have sensors built into the wheel assembly, which requires more work. Luxury and high-performance vehicles sometimes have more expensive sensors, pushing the total cost higher.
You can have the work done at a tire shop, a general mechanic, or a dealership. Tire shops are often the cheapest option and can usually fit you in quickly. Dealerships may charge more but have access to your exact vehicle specifications and can reprogram the system if needed.
When you can safely drive with a fault message
A tire pressure monitor fault does not make your vehicle unsafe to drive. The system is a convenience feature that alerts you to pressure problems; it is not a safety system like brakes or airbags. You can drive normally as long as you check your tire pressure manually every week or two.
However, you should not ignore the fault indefinitely. A faulty sensor means you have lost one layer of protection against slow leaks or punctures. If you do not notice a pressure drop on your own, a tire could become dangerously underinflated without warning.
If the fault message is accompanied by a low-pressure warning — a separate alert — that means at least one tire is actually low on air. In that case, add air when ready and then address the sensor fault at your next opportunity.
Sensor faults after a tire repair or replacement
If a fault appeared right after you had a tire repaired, rotated, or replaced, the sensor may have been damaged or disconnected during the work. Contact the shop and describe when the fault started. Many shops will recheck their work for free if the problem happened during their service.
When you take your vehicle in for tire work in the future, ask the technician to note the sensor locations and be careful around them. Some shops charge an extra $10 to $20 per wheel to handle sensors carefully during tire service, which is worth the cost if you want to avoid damage.
Frequently Asked Questions
Can I ignore a tire pressure monitor fault and keep driving?
Yes, the fault itself is not dangerous — you can drive safely as long as you check tire pressure manually every week. However, you lose the automatic alert system that catches slow leaks, so you must stay vigilant. The fault should be repaired within a few weeks to restore full monitoring.
Is a tire pressure monitor fault the same as a low tire pressure warning?
No. A fault message means the sensor is broken or not communicating. A low-pressure warning means the sensor detected that one or more tires are actually low on air. You may see both messages at once if a sensor is faulty and a tire is also underinflated.
How long do TPMS sensor batteries last?
Most TPMS sensor batteries last between 5 and 10 years. The exact lifespan depends on the sensor brand, how often the system transmits data, and climate conditions. Once the battery dies, the entire sensor unit must be replaced — the battery cannot be replaced separately.
Will the fault go away on its own?
No. A sensor fault will not resolve without repair. If the fault is caused by a dead battery, a corroded connection, or a damaged sensor, only a technician can fix it. The message will remain on your dashboard until the sensor is replaced or the wiring is repaired.
Can I replace a TPMS sensor myself?
Replacing the sensor itself is difficult without special tools, but removing the tire and accessing the sensor is possible if you have basic mechanical skills. Most people have a shop do it because the sensor must be programmed to your vehicle after installation, which requires a special tool that most home mechanics do not own.