On the first cold November morning in San Ramon, the tire light on your RAV4 comes on before you leave the driveway. Usually none of the four tires has a leak, because air inside a tire shrinks as it cools, and the pressure falls about 1 psi for every 10 degrees the temperature drops. A tire set on a warm afternoon can sit several pounds lower by sunrise. At Driven Auto Care of San Ramon, we start the fix with the air in all four tires, well before any reset.
Why the Light Comes On Before Sunrise
Each wheel on a RAV4 carries a small sensor at the valve stem that radios its tire's pressure to the vehicle. Federal rules call for the warning once a tire falls 25 percent or more below the cold pressure printed on the door placard. Overnight is when the air is coldest, so a tire that was close to that line at dinner can cross it by morning. As you drive, the tires warm up and the pressure climbs back, which is why the light can go out on its own by lunch. The tires are still low the next cold morning, so they need air.
The Right Number Is on the Door Jamb
Your RAV4's correct pressure is on the sticker inside the driver's door jamb, and it's a cold number. The figure molded into the tire's sidewall is the most air that tire can safely hold, so it's the wrong target for daily driving. Check the tires in the morning before the RAV4 has moved, because a few miles of driving warms the air and raises the reading. Fill all four to the placard, and include the spare on models where it has a sensor.
Set the Air First, Then Register It
Toyota's procedure has you set every tire to the placard pressure before you initialize the system. Toyota lists the times to initialize as after a change to the tire pressure you run, after a change of tire size, after rotating the tires, and after new sensors are registered. Getting the air right first lets the system start from the correct pressures on all four tires.
The reset itself depends on the model year. On many 2019 and later RAV4s, you park, turn the ignition on, choose the tire pressure setting on the screen between the gauges, and hold the OK button until the tire light blinks three times. Earlier generations use a small reset switch under the dash instead. On either type, the procedure won't run while the vehicle is moving.
When the Light Blinks Before It Stays On
When the tire light blinks for about a minute at start-up and then stays on steady, we look for a fault in the system itself, separate from low air. Adding air to the tires leaves this blinking light on. The usual cause is a sensor that has stopped sending its signal because the sealed battery inside it has run down with age. A wheel or tire change can also leave a sensor unregistered.
For a steady light, we bring each tire up to the door placard figure while the tires are cold, then register the new pressures. For a blinking light, we read each sensor on a scan tool to find the one that has gone silent, replace it, and register its code with the vehicle. We also offer a free Confidence Inspection when you bring your RAV4 in for the tire light.
Bring Your RAV4 In
Call Driven Auto Care of San Ramon at (925) 830-4701 about the warning on your RAV4. When you bring it in, we set the pressures and check the sensors on all four wheels. Then we'll run the reset, and you'll drive away with the light off for the right reason.
