How do I know if my TPMS sensor is going bad?

Yes — warning lights, erratic readings, or a fault message are common signs that a TPMS sensor may be failing. Direct sensors have a finite battery life and typically need replacement after several years. If you notice any related symptoms, a diagnostic check is recommended to confirm the cause.

TPMS, or Tire Pressure Monitoring System, comes in two main flavors: direct TPMS with sensors mounted inside each tire and indirectly monitored systems that estimate pressure using ABS wheel-speed data. Understanding which type you have helps explain why warnings appear and how to fix them. A professional diagnostic scan is usually required to identify the exact sensor or system fault and to perform any necessary relearns after tire work.

Symptoms of a failing TPMS sensor

Below are the most common indicators that your TPMS may be going bad. A quick check against these signs can help you decide whether to seek professional service.

• Your TPMS warning light stays on, even when you’ve recently inflated the tires to the recommended pressure.


• Reading values in the vehicle display are inconsistent, or one tire shows a persistent “low” message while others do not.


• The warning light flashes on startup or you see a “TPMS Fault” or “Service TPMS” message on the dashboard.


• After rotating tires or replacing a tire, the system cannot be relearned or throws errors during the relearn process.


• You notice physical issues like a damaged sensor, a corroded valve stem, or a tire with a slow leak around the valve area.


• The system reports a problem even though the tires appear properly inflated, suggesting the sensor’s battery or electronics may be failing (common in older vehicles).

These signs don’t always mean a sensor is dead — they can also indicate a leak, valve damage, or a failing receiver. A professional diagnostic can distinguish between a simple pressure issue and a true sensor fault.

Direct vs indirect TPMS: how they differ and why it matters

Understanding which type of TPMS you have helps explain the symptoms and the repair approach. Direct TPMS uses physical sensors inside each tire; indirect TPMS estimates pressure using ABS wheel-speed data. Each type has different failure modes and maintenance needs.

Direct TPMS (in-tire sensors)

Direct sensors report actual tire pressures and send data to the vehicle's computer. They require a battery in every sensor and are susceptible to certain failure modes.

• Battery life is finite; most sensors last about 5–10 years, depending on usage and climate.


• Sensors and valve stems can corrode, be damaged by road hazards, or leak, causing inaccurate readings or failure to transmit.


• When a sensor fails or its battery dies, replacement of the sensor (and sometimes the valve) is usually required, followed by a relearn to sync with the car.

Direct TPMS replacement typically involves a new sensor and relearn procedure, and in many cases, the battery cannot be replaced separately. This makes sensor replacement the common remedy when the battery dies or a sensor fails.

Indirect TPMS (estimated pressures via ABS)

Indirect TPMS doesn’t carry a pressure sensor in the tire. It uses the ABS wheel-speed sensors to infer relative pressure by comparing tire rotation. It can be less precise and may be slower to react to changes.

• No battery to replace since there are no tire-mounted sensors.


• Reliant on the vehicle’s ABS system; readings can be affected by tire size changes, wear, or uneven tread, potentially causing false alerts.


• Relearn requirements, if any, vary by vehicle and may occur after wheel or tire changes, but some setups do not require sensor replacement when issues arise.

Indirect TPMS can be more economical upfront but may not detect slow leaks as reliably as direct sensors. If your indicators point to a TPMS fault in an indirect system, it’s still wise to verify actual tire pressures with a gauge and inspect tires for wear or damage.

What to do if you suspect a bad TPMS sensor

If you think your TPMS is failing, follow these practical steps to verify the issue and determine the best path to repair.

• Check all tires with a reliable tire pressure gauge and compare results to the vehicle’s recommended pressure sticker (usually on the door jamb) and to each tire’s intended pressure.


• Inspect tires and wheels for damage, punctures, or corroded valve stems that could cause false readings or leaks.


• Have a professional read the TPMS with a diagnostic tool to identify the specific sensor IDs, pressures, and battery status if available, and to confirm whether a relearn is needed.


• If a sensor is determined to be faulty, replace the sensor(s). Direct TPMS usually requires sensor replacement rather than battery replacement, followed by a system relearn.


• After any tire work or sensor replacement, perform the required relearn procedure as specified by the vehicle manufacturer; this may involve drive cycles or a scan tool.


• Monitor over the next few days to ensure the warning light stays off and that readings stay consistent across all tires.

Timely inspection is important: driving with an unresolved TPMS fault can mask underinflation, which increases wear and reduces fuel efficiency. Most repairs are completed within a few hours at a tire shop or dealership, depending on the vehicle and parts availability.

Costs, timelines, and maintenance tips

Costs depend on whether you’re dealing with a direct or indirect TPMS and whether OEM or aftermarket sensors are used. Here are general ranges to set expectations.

• Direct TPMS sensor replacement (per sensor): roughly $40–$100 for the part, plus $20–$60 for labor and relearn. OEM sensors tend to be pricier.


• Direct TPMS battery replacement is rarely offered; most techs replace the whole sensor.


• Indirect TPMS adjustments are typically less expensive, since there’s no tire-mounted sensor, but diagnosis can still require a diagnostic tool and potential software updates.

Maintenance tips to extend TPMS life include keeping tires properly inflated, avoiding harsh impacts that can damage sensors, and scheduling regular wheel and tire service with a shop familiar with TPMS relearns. If you frequently rotate tires or change wheelsets, ask your shop about the relearn requirements for your specific vehicle.

Summary

TPMS problems are usually signaled by warning lights, inconsistent readings, or fault messages. Direct sensors have batteries that can die within 5–10 years, often necessitating sensor replacement and a relearn, while indirect systems rely on ABS data and may behave differently. Start with verifying tire pressures and inspecting for damage, then use a professional diagnostic tool to confirm the issue and perform the necessary relearn or replacement. Prompt attention helps prevent underinflation risks and keeps your vehicle operating safely and efficiently.

How do I know if I need new TPMS sensors?

You may need new TPMS sensors if the warning light stays on after you've properly inflated your tires, if the system shows inaccurate readings, or if the light blinks and then turns solid, which indicates a system malfunction. Additionally, sensors have a lifespan of about 5 to 10 years and their batteries will eventually die, so they may need to be replaced as part of routine maintenance. 
Signs of a faulty sensor

• Persistent TPMS light: The light remains on after all tires are inflated to the correct pressure, which is often found on a sticker inside the driver's side door jamb. 
• Flashing light: A blinking TPMS light that then turns solid is a strong indicator that the system has a malfunction and at least one sensor is not communicating properly. 
• Inaccurate or missing data: Your vehicle's display shows incorrect tire pressure, or a blank or error message for one or more tires. 
• False alarms: The system repeatedly alerts you to low pressure when the tires are properly inflated. 
• Issues after tire service: The warning light comes on or a sensor fails shortly after getting new tires, which could be due to damage during the installation or a sensor that was already failing. 

When to consider replacement as a preventative measure

• Sensor age: TPMS sensors have a limited lifespan of about 5 to 10 years, as their internal batteries will eventually die. 
• When replacing tires: It is often cost-effective to replace the sensors at the same time you are changing your tires, since the tires must be removed to access the sensors anyway. 

Can AutoZone fix TPMS sensors?

At AutoZone, we carry replacement TPMS sensors for most makes and models. And if you need help resetting the TPMS light, we can offer helpful advice or refer you to a shop in our professional network.

What happens when a TPMS sensor goes bad?

If a TPMS sensor is bad, the vehicle may have an illuminated TPMS warning light, display incorrect or fluctuating pressure readings, and the driver may experience a loss of safety features. Inaccurate or absent warnings can lead to driving with underinflated tires, which decreases fuel economy, increases tire wear, and reduces vehicle handling and braking efficiency, increasing the risk of an accident.
 
Symptoms of a bad TPMS sensor

• Illuminated TPMS light: The warning light on the dashboard stays on even when all tires are properly inflated. 
• Inaccurate readings: The pressure displayed in the vehicle's information system does not match the actual pressure when manually checked. 
• Fluctuating readings: Tire pressure values jump around erratically. 
• No data displayed: A blank screen or error message may appear for one or more tires. 
• Frequent alerts: The system repeatedly triggers false alarms about low or high pressure. 
• Issues after service: Problems appear shortly after tire replacement or rotation. 

Consequences of driving with a bad sensor

• Reduced safety: Without proper alerts, you may not know if a tire is dangerously underinflated, which can reduce traction, steering response, and braking efficiency. This increases the risk of accidents, especially in slippery conditions. 
• Decreased fuel economy: Underinflated tires increase rolling resistance, forcing the engine to work harder and burn more fuel. 
• Premature tire wear: Uneven wear occurs on underinflated tires, leading to a shortened lifespan and the need for earlier replacement. 

What to do

• Do not ignore it: While you can technically drive with the TPMS light on, it's not recommended due to the safety and performance issues it can cause. 
• Check your tire pressure manually: Even with a faulty sensor, manually check the pressure in all your tires to ensure they are properly inflated. 
• Have it diagnosed and replaced: A professional can diagnose the specific sensor that is failing and replace it. The TPMS sensor batteries typically last 5-10 years and will eventually need replacement. 

How do you diagnose a bad TPMS sensor?

Fill each tire until it reaches its recommended tire pressure. Then, gently release air from each tire and monitor the car display panel. If you release pressure from one tire and it doesn't trigger the system, it might mean that the sensor is defective.