Low Tire Light on AGAIN, why? It may only be 3-4 psi low, but thats all it take somtimes. It’s good to know your tire pressures, especially if you have a 8-08 or newer vehicle because these have Direct TPMS.
What’s TPMS? Tire Pressure Monitoring System. Each wheel has a sensor that is able to measure the actual pressure in each tire and send an RF signal to a receiver. This receiver alerts the driver either by a light or an actual pressure at a specific tire as indicated on the dash board.
Also don’t forget the spare tire, if it’s a full size, I bet it also has a sensor too.
You can find the required pressure for front and rear tires (sometimes they are different) located on a placard usually in the drivers side door jam.
Now it is important to know whether this is the warm or cold pressure that is required. The psi is usually 2-3 lbs. lower when cold. So if you have to drive to an air pumping station to fill up, and the tires are now warm, if you set it exactly to the required COLD pressure, they will be 2-3lbs. low in the morning.
I have had cars come in with an actual psi of 31, and the required was 33 and it turned the light on. After correcting the pressure, most cars will adjust automatically after the car is driven above 29 mph for a few minutes.
If the light still does not go out, check your owners manual, there may be a specific procedure. And if that doesn’t help, go by your local repair shop and have them read the TPMS sensor pressures with a tool designed specifically for this. We have two tools, the Bartec and an OTC. If the sensor does not transmit a signal, the battery may have gone dead and complete sensor replacement will be required.
Hope this helps