What your TPMS is Telling you
The low tire pressure indicator in Honda vehicles with TPMS is set to come on when the tire pressure drops 20 percent. All Honda Owners Manuals recommend that the tire pressures be checked and set at least once per month. Each tire should be checked cold, meaning that the vehicle has been sitting for at least 3 hours or driven for less than 1 km.
All tires (even those in good condition) lose tire pressure naturally. It's common to lose up to 1.5 PSI per month. Secondly, it's a scientific fact that tire pressure drops when there is a drop in temperature. You can count on a loss of 1 PSI for every 5.5°C of temperature drop. Here's what can typically happen:
It's August 1st and the temperature outside is a balmy 27°C. You check and set your tire pressures to 32 PSI, just like it says on the driver's doorjamb sticker and in the Owner's Manual. We fast forward to November 1st and the temperature outside is now a nippy 10°C. You check the tire pressures, but now they're reading only 25 PSI and on top of that, the low tire pressure indicator in the dashboard is on.
Remember what that low pressure indicator is telling you: it's not saying there's a problem with the TPMS. To make things right, first check the tire pressures; if they're all lower than the recommended cold inflation pressures, fill the tires to the mentioned pressures. If the low tire pressure indicator stays on after you've completed this step, drive the vehicle over 50 km/h for about 1 minute; the indicator should go out. Otherwise, if one tire pressure reading is vastly different than the rest, there may be a leak in the tire.
Again, it is recommended to check and set the tire pressures monthly, otherwise, the low tire pressure indicator is going to be coming on and because of the cold weather, that could be more often than not. So here's the bottom line: The low tire pressure indicator is like a "low fuel indicator" for the tires; think of it as just another maintenance item - it's really no different than filling up the fuel tank when the low fuel sign displays.
For more step by step information on how to check your tire pressure, click here.