Your Tire Pressure Monitoring System (TPMS) warning light communicates two distinct problems depending on how it illuminates on your dashboard. A solid light indicates a tire pressure issue, while a light that flashes for 60 to 90 seconds before turning solid indicates a malfunction within the TPMS system itself. Diagnosing the root cause requires observing this behavior as soon as you start your vehicle.
Solid TPMS Light: Tire Pressure Alert
A TPMS light that comes on solid and stays solid means that one or more of your tires are underinflated or overinflated past the manufacturer's safe threshold (usually a 25% variance).
Common Causes
Puncture or Leak: A nail, a damaged valve stem, or a poor bead seal is allowing air to escape.
Cold Weather Drops: Air condenses in cold temperatures. A drop of 10°F can reduce tire pressure by 1 to 2 PSI. It is common for a solid light to trigger on cold mornings and turn off later in the day as driving heats and expands the air inside the tire.
Spare Tire Deflation: Many modern vehicles equip the spare tire with a TPMS sensor. If the spare in your trunk loses air over time, it will trigger a solid dash light even if your four primary tires are perfectly inflated.
How to Fix It
Pull over safely and use a manual tire pressure gauge to check all four tires (and the spare). Inflate or deflate the tires to match the recommended PSI listed on the sticker located inside the driver-side door jamb, not the maximum pressure printed on the tire sidewall. Once properly inflated, the light should turn off automatically after driving a few miles at city speeds.
Flashing TPMS Light: System Malfunction
If the TPMS light flashes or blinks for 60 to 90 seconds when you start the car and then remains solid, the system is failing to communicate with one or more of the wheel sensors. The TPMS is out of order and cannot accurately warn you of a tire blowout.
Common Causes
Dead Sensor Battery: Direct TPMS sensors are powered by internal lithium-ion batteries that last 5 to 10 years. When the battery dies, the sensor stops transmitting, and the light flashes. Learn more about Direct Vs Indirect TPMS
Damaged Hardware: Sensors are easily snapped or damaged by tire technicians during mounting and dismounting.
Lost Programming: If you recently rotated your tires, swapped to winter wheels, or installed a new sensor without properly reprogramming the vehicle's computer, the system will not recognize the sensors.
How to Fix It
Because a flashing light points to an electronic failure, adding air to your tires will not solve the problem.
Verify that your tire pressures are physically safe using a manual gauge.
Take the vehicle to a tire shop or use an OBD2 scan tool to read the TPMS diagnostic trouble codes (DTCs). The scanner will identify exactly which wheel has the dead or missing sensor.
Replace the faulty sensor and perform a relearn procedure to sync the new hardware with your vehicle's computer.
You Should learn more about the relearn process: How to Reset a TPMS Sensor.
Can You Drive With the TPMS Light On?
If the light is solid and you have manually verified with a gauge that the pressure drop is minor (e.g., 28 PSI instead of 32 PSI), you can safely drive at low speeds to the nearest air compressor. Driving on severely underinflated tires causes excess friction, overheats the rubber, accelerates tread wear, and significantly increases the risk of a high-speed blowout.
If the light is flashing, the physical air pressure in your tires might be perfectly fine, allowing you to drive safely. However, a flashing light means you are driving without an active early warning system. If you run over a nail on the highway, the car will not be able to warn you that the tire is deflating until you feel it in the steering wheel.
(For a broader overview of how these sensors protect your vehicle, return to our Tire Pressure Monitoring System (TPMS): Complete Guide.