A solid TPMS light means one or more tires are low on air — check pressures against the sticker in your door jamb and inflate soon; it is usually just cold weather or a slow leak. A flashing light (it typically blinks for 60–90 seconds after start-up, then stays on) means the TPMS system itself has a fault — a dead sensor battery, a missing sensor, or one that needs relearning — and that needs a diagnosis, not just air.
Solid light: a tire is low
A steady TPMS light is the simple case: at least one tire has dropped below its target pressure. The target is on the placard inside the driver's door jamb — not the number moulded on the tire sidewall, which is the maximum, not the recommendation.
Nine times out of ten the cause is cold weather or a slow leak — a nail, a corroded valve stem, or a rim that no longer seals perfectly. Top the tire up and watch it: if the light comes back within a few days, something is leaking, and a slow leak caught early is usually a straightforward tire repair.
Don't just live with the light. An underinflated tire wears its shoulders faster, drags on your fuel economy, and runs hotter — heat is what kills tires, especially at highway speed.
Flashing light: the system itself has a fault
If the light flashes for about 60–90 seconds after start-up and then stays solid, the car isn't telling you about air — it is telling you the TPMS system can't do its job. The usual causes:
- A dead sensor battery. The battery is sealed inside the sensor and lasts roughly 5–10 years — cars from the mid-2010s are hitting sensor end-of-life in waves right now.
- A missing sensor — a spare or winter wheel without one, or a sensor damaged during a previous tire change.
- A sensor that needs relearning. After a rotation or a tire change, some vehicles need the sensors re-registered to their new positions.
A flashing light needs a diagnosis: no amount of inflating will clear it, and while it is faulted the car may not warn you about a genuinely low tire.
Why the light loves the first cold morning
Air contracts as it cools: every ~10°C drop costs a tire roughly 1 psi. Tires set in a warm September afternoon can be 3–4 psi down by the first frosty morning in October — just enough to trip the warning. That is why TPMS lights come on in waves across the GTA the moment fall arrives.
The fix is simply to set pressures for the season, checked cold (before driving). Often the light even goes off by itself once the tire warms up mid-drive — that is the classic cold-morning signature, but it still means you are running low and should top up. If you are about to swap onto winter tires anyway, a winter package on its own wheels can carry its own sensor set, so the seasonal changeover never triggers the light in the first place.
What we do about it at Taylor Tire
TPMS is one of our specialties. Bring the car in and we diagnose on the spot: read each sensor, tell you exactly which one is dead, missing, or unregistered, and fix it the same visit — we stock, program and install all major sensor types, so there is no ordering wait for common vehicles. Off the public rate card: programming is $20 a sensor, a replacement sensor is $70 installed.
We also handle the relearn after installations and rotations, and when we build a winter package we can fit it with its own sensors so both sets of wheels stay fully monitored year-round. Serving Markham since 1978 — call (905) 475-2104 or book online.
What to do right now
- Find the pressure placard inside the driver's door jamb and note the front and rear numbers.
- Check all four tires with a gauge (cold, before driving) and inflate any that are low — including the spare if it has a sensor.
- Drive normally; on most vehicles the light clears itself within a few minutes once pressures are right.
- If the light returns within days, or it flashes at start-up, book a diagnosis — that is a leak or a sensor fault, not something air will fix.
Common questions
Is it safe to drive with the TPMS light on?
For a short distance at moderate speed, usually yes — but check pressures as soon as you can. A significantly underinflated tire runs hot and can fail, so if the car pulls, vibrates, or a tire looks visibly low, stop and check it before driving on.
Why does my TPMS light flash and then stay on?
That flash-then-solid pattern is the fault signal: the TPMS system itself has a problem — most often a sensor with a dead battery, a missing sensor, or one that needs relearning. It needs a diagnosis; inflating the tires will not clear it.
How long do TPMS sensor batteries last?
Roughly 5 to 10 years, depending on driving. The battery is sealed inside the sensor, so when it dies the sensor is replaced as a unit — we program and install all major sensor types the same visit.
Do I need new TPMS sensors for winter tires?
Not necessarily — sensors can be swapped between wheels, but many drivers put a second set in the winter wheels so the seasonal changeover is faster and the light never comes on. Ask us to quote it with your winter package.
Sources
- TireWise: TPMS and tire-pressure safety — NHTSA Verified
- Know the signs of tire wear and TPMS warnings — Chevrolet Verified
Questions about your own car? Bring it to Taylor Tire for a clear answer, an all-in price and same-day service when the schedule allows.