Is it OK to drive with bad TPMS sensor?
Not advisable. A faulty TPMS can hide tires that are underinflated, increasing the risk of a blowout, reduced handling, and uneven tire wear. If you suspect the sensor is failing, have the system diagnosed and repaired promptly; you may drive briefly to a shop, but avoid long trips until fixed.
Tire Pressure Monitoring Systems (TPMS) are designed to alert you when a tire’s pressure drops too far. There are two main types: direct TPMS, which uses sensors installed in each wheel, and indirect TPMS, which infers low pressure from ABS data. A malfunctioning TPMS can leave you unaware of dangerous tire conditions, compromising safety and potentially affecting fuel economy and tire life. This article explains how TPMS works, what to do when the light comes on, and what to expect if a sensor needs replacement.
How TPMS works and why failure matters
Direct TPMS measures each tire’s pressure with a sensor in the valve stem and reports values to the car’s computer. Indirect TPMS does not measure pressure directly; instead, it compares wheel speeds and tire dimensions to detect possible underinflation. If a sensor fails or the system loses calibration, you may stop receiving accurate warnings or any warning at all, which can leave underinflated tires unnoticed.
Direct vs indirect TPMS
Direct TPMS provides real-time readings for each tire and a warning if one tire falls below a threshold. Indirect TPMS relies on ABS/wheel-speed data to flag potential underinflation but does not show exact pressures. Direct sensors typically have a battery life of several years, while indirect systems depend on the vehicle’s ABS/ACU logic and calibration.
What to do if the TPMS warning light comes on
When the warning appears, follow these practical steps to stay safe and identify the cause.
- Check all tires with a reliable gauge to verify actual pressures, including the spare if applicable.
- Inflate each tire to the manufacturer’s recommended pressure, usually listed on a sticker on the door jamb or in the owner’s manual, then recheck after driving a short distance.
- Inspect tires for visible damage, punctures, or slow leaks and address any issues before continuing your trip.
- If the light stays on or you suspect a sensor fault, schedule service to diagnose the TPMS sensor, relearn the system, or replace components as needed.
Addressing the warning promptly helps preserve safety and tire life. If you can’t reach a shop right away, drive cautiously and monitor tire pressures manually until you can get professional service.
Common causes of TPMS sensor failure and replacement options
Understanding why a TPMS sensor fails can help you plan repairs and costs. The following list covers typical failure modes and what they usually entail.
- Dead or failing battery inside a direct TPMS sensor, a common reason for sensor replacement after several years.
- Physical damage to sensors from impacts, wheel changes, or corrosion, which may require sensor replacement.
- Worn or damaged valve stems that can trigger TPMS faults and may necessitate stem replacement and resealing.
- Corrosion or mounting issues at the sensor or wheel hub that disrupt signal or readings, sometimes requiring sensor or wheel service.
After sensor replacement, a TPMS relearn or reset is often needed to re-sync the system with the vehicle. Replacement costs vary, but you can expect sensor units to run roughly $50–$150 each, plus labor and potential wheel balancing.
Safety and legal considerations
TPMS is a safety feature designed to prevent driving on underinflated tires. In many regions, new vehicles must have a functioning TPMS, and inspections or regulations may flag a persistent TPMS fault. Driving with a known malfunctioning TPMS is not universally illegal, but it increases safety risk and could affect inspections, warranties, or insurance considerations. If the system indicates a fault, treat it as urgent maintenance and seek professional service promptly.
Summary
In short, driving long-term with a bad TPMS sensor is not advisable. It can mask dangerous underinflation and lead to unsafe driving conditions, higher fuel usage, and accelerated tire wear. Check tire pressures manually if needed, and arrange professional diagnostic and repair to restore accurate monitoring. Regular maintenance and timely sensor replacement help ensure safety, performance, and compliance.
