What to Do When Your TPMS Light Comes On in Vancouver

The TPMS warning light on your dashboard is one of those alerts that prompts a split-second decision: is this urgent, or can it wait until the weekend? In Vancouver, where temperature swings between seasons — and sometimes within a single day — can be dramatic, tyre pressure fluctuates more than most drivers realise. Understanding what the light is telling you, what it is not, and what to do about it is worth a few minutes of your attention.

Why Temperature Changes Affect Tyre Pressure

Tyre pressure is measured in pounds per square inch (psi) and is calibrated for a specific temperature: the ambient air temperature inside the tyre at the time it was set. For every 10°F (6°C) drop in temperature, tyre pressure falls by approximately 1 psi. In Vancouver, it is not unusual for overnight temperatures to drop 15 to 20 degrees between a warm autumn evening and a clear winter morning — that is a 1.5 to 2 psi drop in pressure overnight, with no puncture, no slow leak, and nothing wrong with the tyre.

This means that a tyre set to 35 psi on a mild October afternoon may read 31 or 32 psi on a cold January morning. If the TPMS threshold on your vehicle is set at 31 psi, the light comes on — not because the tyre is failing, but because it is cold.

What Your TPMS Light Actually Means

There are two types of TPMS: direct and indirect. Direct TPMS uses a sensor inside each tyre that measures actual pressure and temperature, typically triggering the light when pressure falls 25% or more below the recommended level. Indirect TPMS uses the vehicle's ABS wheel-speed sensors to detect when a tyre is rotating at a different speed than the others — which happens when its diameter changes due to lower pressure. Indirect systems cannot tell you which tyre is low or by how much.

Regardless of system type, the light has one job: to alert you that at least one tyre is outside the manufacturer's recommended pressure range. It does not tell you whether that is due to a slow leak, a temperature drop, or a sudden puncture. That is your job to determine.

When to Act Immediately vs. When to Wait

The light is urgent if: the tyre visibly looks flat or significantly underinflated, you heard a loud bang or felt a impact before the light came on, the light is flashing rather than solid (some systems flash to indicate a sensor fault rather than a pressure problem), or you are far from a service location and cannot check the tyre yourself.

The light is likely temperature-related if: it came on overnight or first thing in the morning after a cold night, all four tyres are affected rather than just one, the pressure reading at a gauge is close to — but slightly below — the recommended level, and the light goes off after driving for 15 to 20 minutes as the air inside the tyre warms and expands.

If you are unsure, check all four tyres with a gauge at the earliest opportunity. Most gas stations have a pressure gauge available. Compare readings against the driver's door jamb or fuel door sticker — that figure is the cold tyre pressure target, not the number on the tyre sidewall.

Winter Tyre Pressure in Vancouver

Winter introduces two compounding factors: lower temperatures and the switch to winter or all-season tyres. Winter tyres are designed to be run at slightly lower pressure than summer tyres — typically 2 to 4 psi lower — to allow the tyre to flex more and generate heat. Consult your vehicle's winter tyre specification and the tyre manufacturer's pressure recommendation for winter use.

Driving on winter tyres at the same pressure as summer tyres is a common mistake. The tyre is designed to perform correctly at the specified winter pressure; running it higher reduces the contact patch and compromises winter grip. Running it significantly lower than specified is equally problematic — the tyre sidewall bears more load than it is designed for and can overheat.

Checking and Inflating Your Tyres in Vancouver

The most reliable place to find your correct tyre pressure is the sticker on the driver's door jamb — not the sidewall. The number on the sidewall is the maximum the tyre can handle, not the optimal pressure for your vehicle.

Check tyre pressure when the tyres are cold — before driving, or at least three hours after the last drive. Warm tyres give falsely high readings because the air inside has expanded.

If you are inflating at a gas station, bring a personal gauge to verify the station's accuracy — mechanical gauges wear out and can be inaccurate by several psi. A small discrepancy between the station's readout and your gauge is common; a large one means the station's gauge is unreliable.

When to Bring It to a Professional

If the TPMS light remains on after inflating the tyres to the correct pressure, or if you are adding air regularly — more than 2 to 3 psi per month — without a corresponding temperature explanation, there is likely a slow leak. Tyres lose pressure through the valve stem, a small puncture, or bead sealing issues. A slow leak that is not addressed will eventually lead to a flat, and an underinflated tyre generates heat that can cause catastrophic failure at motorway speeds.

For a proper tyre inspection, pressure check, and TPMS diagnostic, visit our tires service page or browse our Land Rover Defender PPF portfolio project to see our work on a vehicle equipped with performance tyres.